Introduction
Mantids represent a prominent group of predatory insects with a substantial role in regulating arthropod populations across diverse ecosystems. Many species exhibit remarkable camouflage, remaining motionless for extended periods while ambushing prey. Equipped with raptorial forelegs, mantids capture a wide range of insects, small arthropods, and even conspecifics. Their widespread distribution highlights their ecological precision in sustaining insect population balance (Sampaio et al., Reference Sampaio, Bueno, Silveira and Auad2009). Hierodula tenuidentata Saussure, 1869 (Mantodea: Mantidae) and Empusa fasciata Brullé, 1832 (Mantodea: Empusidae) are two mantid species recorded in Iran. Hierodula species are predominantly active in humid, vegetated environments, including gardens and urban green zones, whereas Empusa species are more frequent in semi-arid and mountainous habitats (Mirzaee and Pashaie Rad, Reference Mirzaee and Pashaie Rad2017; Moradzadeh et al., Reference Moradzadeh, Pashaei Rad and Shahbazi2021). Their active periods span spring and summer, while overwintering occurs in the oothecal and nymphal stages, respectively (Mirzaee et al., Reference Mirzaee, Sadeghi and Battiston2022, Reference Mirzaee, Simões, Battiston, Sadeghi, Wiemers and Schmitt2024).
Insects frequently encounter starvation, dietary shifts, and environmental stressors, particularly among predatory species, due to fluctuations in the availability of their prey. Nutritional macromolecules are essential for growth, reproduction, enzymatic activity, moulting, and overall physiological resilience (Kang et al., Reference Kang, Kamita, Suzuki and Seong2011; Maggini et al., Reference Maggini, Beveridge and Suter2012; Le Gall and Behmer, Reference Le Gall and Behmer2014). Starvation or nutrient-poor diets prolong immature stages, alter pupal mass and adult longevity (Littlefair and Knell, Reference Littlefair and Knell2016), and compromise internal defence mechanisms, reducing the capacity to manage pathogenic threats (Siva-Jothy and Thompson, Reference Siva-Jothy and Thompson2002; Zhu et al., Reference Zhu, Yuan, Yao, Liu, Tao and Huang2012; Stączek et al., Reference Stączek, Zdybicka-Barabas, Wiater, Pleszczyńska and Cytryńska2020).
The insect defence system, comprising both cellular and humoral components, serves as the final barrier against microbial agents, xenobiotics, and abiotic stresses (Lavine and Strand, Reference Lavine and Strand2002; Beckage, Reference Beckage2008). Hemocytes, the primary effector cells, respond to challenges by altering their abundance, morphology, and activity (Strand, Reference Strand2008). As such, changes in hemocyte parameters provide a sensitive proxy for evaluating circulatory competence and stress responses. Nutritional deprivation or low quality food strongly influences these dynamics. For example, 1 week of starvation in damselfly larvae Coenagrion puella (Linnaeus, 1758) (Odonata: Coenagrionidae) resulted in weight loss, reduced hemocyte density, and suppressed phenoloxidase activity (Campero et al., Reference Campero, Block, Ollevier and Stocks2008). In bumblebees, low-protein diets significantly altered circulating cell profiles (Roger et al., Reference Roger, Michez, Wattiez, Sheridan and Vanderplanck2017). Samia cynthia (Drury, 1773) larvae fed on cassava leaves – rich in essential nutrients – exhibited heightened cell-mediated defence compared to those reared on artificial diets (Manjula et al., Reference Manjula, Lalitha and Shivakumar2020). Host plant chemistry has also been shown to influence defence allocation in Junonia coenia Hübner, 1822 (Carper et al., Reference Carper, Enger and Bowers2019). The impact of nutritional stress is further modulated by developmental stage. In mantid Tenodera angustipennis Saussure, 1869 (Mantodea: Mantidae), younger instars were more sensitive to starvation than nymphs and adults (1981), likely due to higher energy requirements associated with metabolic scaling. Prey quality additionally affects reproductive physiology and feeding behaviour in mantids. In Stagmomantis limbata Hahn, 1835 (Mantodea: Mantidae), richer diets enhanced reproductive output and reduced cannibalistic tendencies (Maxwell et al., Reference Maxwell, Gallgo and Barry2010), while improved food quality in Tenodera sinensis Saussure, 1871 (Mantodea: Mantidae) increased growth and consumption efficiency (Paradise and Stamp, Reference Paradise and Stamp1990).
Alongside nutrition, temperature acts as a major determinant of insect physiology, influencing survival, development, digestion, circulation, and internal defence capacity (Xia et al., Reference Xia, Wang, Xie, Feng and Huang2021; Vogel et al., Reference Vogel, Shah, Voulgari-Kokota, Maistrou, Aartsma, Beukeboom, Salles, Van Loon, Dicke and Wertheim2022; Herren et al., Reference Herren, Hesketh, Dunn and Meyling2023). Insects typically operate within narrow thermal ranges, and deviations from these thresholds can modulate hemocyte dynamics and disrupt systemic homeostasis. Exposure to high or low temperatures can sharply modify hemocyte density, depending on the developmental stage and species, thereby affecting the insect’s resistance to control measures (Browne et al., Reference Browne, Surlis and Kavanagh2014). For instance, exposure of Phthorimaea operculella (Zeller, 1873) (Lepidoptera: Gelechiidae) larvae to elevated temperatures increased hemocyte counts, whereas cold stress reduced them (Pourali and Ajamhassani, Reference Pourali and Ajamhassani2018). Similarly, diapause larvae of the pistachio wasp Megastigmus pistaciae Walker, 1871 (Hymenoptera: Torymidae) showed markedly reduced hemocyte number compared to their active counterparts under cold exposure (Ajamhassani et al., Reference Ajamhassani, Ebrahimizadeh, Abdos and Ahangi Rashti2023). These effects may be partially mediated by temperature-induced reductions in feeding, which subsequently alter hemolymph volume and cellular defence parameters.
Despite increasing knowledge of how nutrition and temperature shape insect defence physiology, comprehensive data on their combined effects in ambush predators remain sparse. Most studies have focused on generalist herbivores or laboratory models, neglecting species with specialised ecological niches (Matsura, Reference Matsura1981). To date, no comparative investigation has assessed the hemocyte responses of two ecologically distinct mantids – H. tenuidentata and E. fasciata – under simultaneous food restriction, prey variation, and temperature stress. Moreover, there is a lack of data on short-term fluctuations in hemocyte numbers in relation to real-world shifts in diet quality and ambient temperature. This study specifically addresses these gaps by quantifying hemocyte profiles in H. tenuidentata and E. fasciata under starvation, differential prey diets, and thermal extremes. Does hemocyte density decrease uniformly under food deprivation in both species, or do species-specific defence strategies emerge? How do different prey sources modulate cellular response in mantids with contrasting ecological distributions? Do thermal stressors differentially impact hemocyte patterns depending on their intensity or duration? These questions form the core of this investigation. By integrating multiple environmental stressors into a species-comparative framework, this study provides novel insights into the trade-offs between energy acquisition and defence investment in mantids. The findings establish baseline data for future immunophysiological research and offer broader implications for understanding predator adaptation in dynamic ecosystems.
Materials and methods
Mapping of distribution records
To map the distribution of Empusa fasciata and Hierodula tenuidentata in Iran, we compiled occurrence data from all available published literature and supplemented this with new records collected during the present study (fig. 1). For records that did not include geographic coordinates but listed a locality name (such as a city or province), we manually georeferenced the locations using Google Earth v. 9.174.0.2 (https://earth.google.com/web/), based on the information provided on specimen labels or in the published sources.
(A) Red symbols indicate the distribution of H. tenuidentata across Iran, with red circles representing previously published records and red stars showing new records documented in this study. Green symbols depict the distribution of E. fasciata, where green circles correspond to literature records and green triangles represent new findings from this research. All records added in this study are newly documented for the study area. Detailed coordinates and data sources for each occurrence are provided in the supplementary file 1. (B) Miami, (C) Alikahi, (D) Mojen, Mantid sampling area, Semnan Province, Iran.
Figure 1 Long description
A) The map of Iran displays the distribution of Hierodula tenuidentata and Empusa fasciata. Red circles represent previously published records of Hierodula tenuidentata, while red stars indicate new records. Green circles show literature records of Empusa fasciata and green triangles represent new findings. The map includes a scale bar indicating distances of 250 km and 500 km. B) An image of a dry, leafless landscape. C) An image of a green, tree-filled area. D) An image of a barren, rocky terrain with mountains in the background.
All georeferenced records, along with those collected in this study, were used to generate a distribution map in QGIS v. 3.22 (https://qgis.org/en/site/).
Insect rearing
Oothecae of H. tenuidentata in early to mid-spring from plum and apricot trees in the Miami city (36°24ʹ40ʺ N, 55°39ʹ30ʺ E), Alikahi village (36°29ʹ36ʺ N, 54°45ʹ22ʺ E), Bastam city (36°30ʹ16ʺ N, 55°00ʹ18ʺ E), Silu region (35°33ʹ56ʺ N, 53°22ʹ31ʺ E) and oothecae of E. fasciata were collected from thorny shrubs in the Mojen city (36°29ʹ37ʺ N, 54°45ʹ07ʺ E) and the Dezej village (36°21ʹ43ʺ N, 55°01ʹ00ʺ E), Semnan Province, North-East of Iran (fig. 1A–D). Each ootheca was housed individually in a 20 × 20 × 20 cm rearing container and maintained under controlled conditions (25 ± 1°C, 50% relative humidity, 14:10 h light:dark photoperiod). Daily misting was applied to prevent desiccation. Upon hatching, nymphs were separated into individual containers to avoid cannibalism. Each rearing unit included thorny branches for E. fasciata and tree leaves for H. tenuidentata, providing physical support and mimicking their natural habitat. First- and second-instar nymphs were fed Macrosiphum rosae (Linnaeus, 1758) (Hemiptera: Aphididae) aphids, while later instars received mealworms until reaching maturity. M. rosae and mealworms were reared on Rosa sp. and wheat bran, respectively. Representative images of nymphal feeding and adult mantids are shown in fig. 2.
Developmental stages of Hierodula tenuidentata, (A) oothecae, (B) first instar nymph, (C) fifth instar nymph, (D) female adult, (E) male adult and developmental stages of Empusa fasciata, (F) oothecae, (G) 7th instar nymph, (H) 7th instar nymph feeding on Oedipoda sp., (I) female adult, (J) male adult.
Hemocyte identification
To identify hemocyte types, hemolymph was extracted from adult and nymph mantids using a sterile needle inserted into the abdominal region. A drop of hemolymph was transferred onto a clean glass slide, and a thin smear was prepared using a second slide. After air-drying for several minutes, a 9:1 Giemsa solution (Merck KGaA, Germany) was applied to the smear and allowed to stain for 4 minutes. Excess stain was gently rinsed off with distilled water (Yeager, 1945). The underside of the slide was dried using filter paper. Hemocyte classification was performed under an Olympus BH2 light microscope using established morphological criteria and validated identification keys (Gupta, Reference Gupta and Gupta1991; Lavine and Strand, Reference Lavine and Strand2002).
Differential hemocyte count (DHC)
Ten individuals from each nymphal stage (excluding the first instar) and both adult sexes were selected for analysis. Based on established protocols (Yeager, Reference Yeager1945; Arnold and Hinks, Reference Arnold and Hinks1976), the proportion of hemocyte types was calculated within 1–2 µL of hemolymph. Hemolymph collection and Giemsa staining were performed as described for hemocyte identification. One hundred hemocytes were randomly selected at 40× magnification and differentially counted using an Olympus BH2 microscope.
Effect of starvation period on hemocyte count of H. tenuidentata and E. fasciata
Sixth-instar nymphs of H. tenuidentata and E. fasciata were subjected to starvation stress for 12, 24, 72, and 96 hours. The experiment comprised five treatments: a control group fed mealworms and four starved groups exposed to 24, 48, 72, or 96 hours of food deprivation. All individuals were misted daily to maintain hydration throughout the experiment. Each treatment included 10 replicates, with hemolymph extracted from 10 sixth-instar nymphs per species in each replicate (1–2 µL). The extracted hemolymph was immediately mixed with 25 µL of Tyson buffer, an anticoagulant containing methyl violet (0.06 mM), glycerol (43 mM), sodium chloride (NaCl₂, 72 mM), sodium sulphate (Na₂SO₄, 9 mM), and distilled water (250 mL). All reagents were obtained from Merck (Germany). The hemolymph–Tyson buffer mixture was loaded into a Neubauer hemocytometer (HBG, Germany) for quantification. Total hemocyte count (THC), as well as counts of plasmatocytes, granulocytes, prohemocytes, and oenocytoids, was performed under light microscopy at 40× magnification using Jones’ formula (Jones, 1967).
\begin{equation*}\frac{{{\text{Hemocyte count}} \times \,{{1 \text m}} {{\text{m}}^{\text{2}}}\times {\text{ Dilution} \times {Depth\ factor\ of\ the\ chamber}}}}{{{\text{No}}{\text{. of squares counted}}}}\end{equation*}Dilution = 15 times, Depth factor of the chamber = 10, No. of squares counted = 5.
Effect of prey type on hemocyte count of H. tenuidentata and E. fasciata
In this experiment, treatments included six prey types: adults of Musca domestica Linnaeus, 1758, (Diptera: Muscidae), Plodia interpunctella (Hübner, 1813) (Lepidoptera: Pyralidae), Lycaena sp. (Lepidoptera: Lycaenidae), second- and third-instar nymphs of Dociostaurus maroccanus (Thunberg, 1815) (Orthoptera: Acrididae), Oedipoda sp. (Orthoptera: Acrididae) and larvae of Tenebrio molitor Linnaeus, 1758 (Coleoptera: Tenebrionidae). Grasshoppers and L. botrica were collected from herbaceous plants and gramineae in the rangelands of the Shahrood region, Semnan Province, Iran, using an insect net. The remaining prey species were reared under controlled conditions (25 ± 1°C, 50% relative humidity, 14:10 h light:dark photoperiod). P. interpunctella was maintained on an artificial diet consisting of wheat germ, water, glycerine, wax, and malt extract, whereas T. molitor was reared on wheat bran. Newly moulted sixth-instar nymphs of H. tenuidentata and E. fasciata were fed one of these prey types for 7 consecutive days. After 1 week, 2 µL of hemolymph was extracted from each replicate and mixed with 15 µL of Tyson buffer. Using a Neubauer hemocytometer and light microscope at 40× magnification, THC and individual counts of granulocytes, plasmatocytes, prohemocytes, and oenocytoids were determined based on Jones’ formula. Each treatment included 10 biological replicates (10 newly moulted sixth-instar nymphs of mantids).
Effect of thermal stress on hemocyte count of H. tenuidentata and E. fasciata
Fifth-instar nymphs of H. tenuidentata and E. fasciata were used in this experiment, which included ten treatments: control groups maintained at 25 ± 1°C; heat-stressed nymphs exposed to 30°C for 24 and 48 hours; and cold-stressed nymphs exposed to 5°C for 24 and 48 hours. Each treatment included three replicates, with hemolymph (2 µL) collected from one nymph per replicate. The hemolymph was mixed with 25 µL of Tyson buffer. Hemocyte counts – including THC, granulocytes, plasmatocytes, prohemocytes, and oenocytoids – were performed using a Neubauer hemocytometer.
Statistical analysis
All experiments were conducted in the form of a complete randomised design and analysed using SAS 9.1 software program. After normality test, all data were compared by one-way analysis of variance followed by Tukey’s test. Differences between treatments and control were statistically considered at a probability less than 5% and marked by different letters.
Results
In total, we obtained 25 occurrence points for H. tenuidentata and 18 occurrence points for E. fasciata. These records were mapped to visualise the known distribution ranges of both species across the studied region of Semnan Province, Iran (fig. 1).
Hemocyte identification
The circulating hemocytes of adult H. tenuidentata consisted of prohemocytes, granulocytes, plasmatocytes, oenocytoids, and spherulocytes (fig. 3A). Spherulocytes were absent in the nymphal stages of this species. In E. fasciata, the hemolymph at both nymphal and adult stages displayed a similar hemocyte composition, except for the absence of spherulocytes (fig. 3B). Prohemocytes in both species were perfectly spherical, with the smallest size among all hemocyte types. These cells contained a prominent central nucleus, occupying most of the intracellular space, with the cytoplasm forming a thin peripheral layer (fig. 3A,B).
Light microscopy pictures of Hierodula tenuidentata hemocytes (A) and Empusa fasciata hemocytes (B) stained with Giemsa. PR, prohemocyte; PL, plasmatocyte; OE, oneocytoid; GR, granulocyte; SP, spherulocyte. Scale bar = 10 µm.
Granulocytes exhibited a size range from 7.5 ± 2.8 µm, with a visibly granular cytoplasm. In H. tenuidentata, oval granulocytes with dense granule content were observed (fig. 3A, table 1), suggesting high functional activity in defence processes. Spindle-shaped plasmatocytes with one or two cytoplasmic extensions were identified, whereas cylindrical, vermiform, or stellate forms were not observed in either species (fig. 3A,B). Plasmatocytes were the largest cells in both mantids (table 1). Size of them was 10.2 ± 3.1 and 5.7 ± 1.2 µm in H. tenuidentata and E. fasciata, respectively. Plasmatocyte nuclei stained deep blue with Giemsa, confirming their identity. In both species, oenocytoids were larger than prohemocytes and were characterised by a lateral nucleus that distinguished them from other cell types. The size of oenocytoids was 5.2 ± 0.8 µm and 3.2 ± 0.4 in H. tenuidentata and E. fasciata, respectively (table 1).
Morphometric size of hemocytes in two mantids, Hierodula tenuidentata and Empusa fasciata (n = 20)
Table 1 Long description
Measurements are hemocyte length and width in micrometers, reported as mean plus or minus standard error, for each hemocyte type within two mantid species. For Hierodula tenuidentata, prohemocytes measure 3 plus or minus 0.5 in length and 2.9 plus or minus 0.2 in width, plasmatocytes 10.2 plus or minus 3.1 and 4.6 plus or minus 1.2, granulocytes 7.5 plus or minus 2.8 and 5.7 plus or minus 2, oenocytoids 5.2 plus or minus 0.8 and 4.6 plus or minus 0.6, and spherulocytes 8.5 plus or minus 1 and 7 plus or minus 1.7. For Empusa fasciata, prohemocytes measure 1.4 plus or minus 0.2 in length and 1.3 plus or minus 0.3 in width, plasmatocytes 5.7 plus or minus 1.2 and 2.8 plus or minus 0.8, granulocytes 3.7 plus or minus 0.7 and 3.2 plus or minus 0.5, and oenocytoids 3.2 plus or minus 0.4 and 3 plus or minus 0.3. Letter markers appear after each mean in both the length and width columns.
Note: Different letters in each column show significance using Tukey’s test at p < 0.05.
Spherulocytes were found exclusively in the adult stage of H. tenuidentata and represented the large type of hemocyte (8.5 ± 1 µm) (table 1). These cells displayed prominent cytoplasmic spherules, a defining morphological trait (fig. 3A). The dimensions of hemocytes in E. fasciata were generally smaller than those in H. tenuidentata, often measuring approximately half the size (table 1). In H. tenuidentata, plasmatocytes and spherulocytes were the largest hemocytes, whereas in E. fasciata, plasmatocytes were the largest observed cell type.
Differential hemocyte count (DHC)
Table 2 presents the differential hemocyte profiles of H. tenuidentata and E. fasciata. Significant variation was observed across developmental stages in both species. Prohemocytes were most abundant in early-instar nymphs and declined progressively with age, reaching their lowest frequency in the late nymphal and adult stages (F = 55.5, df = 17, p ≤ 0.0001).
Hemocyte frequency (%) of developmental stages in two mantids, Hierodula tenuidentata and Empusa fasciata
Table 2 Long description
Hemocyte frequency is reported as percent for two mantid species across developmental stages, with columns for Prohemocyte, Plasmatocyte, Granulocyte, Oenocytoid, and Spherulocyte, and values given as mean plus or minus a spread with letter markers. For Hierodula tenuidentata, prohemocytes decline from 34.7 in the 2nd instar nymph to 14.3 in the 10th instar nymph, then are 15.0 in female adult and 16.2 in male adult. In the same species, plasmatocytes rise from 11.0 in the 2nd instar nymph to 26.1 in the 10th instar nymph, then are 23.0 in female adult and 21.5 in male adult. Granulocytes in Hierodula tenuidentata increase from 32.6 in the 2nd instar nymph to 46.5 in the 10th instar nymph, then are 43.5 in female adult and 41.0 in male adult. Oenocytoids in Hierodula tenuidentata range from 20.3 in the 2nd instar nymph down to 12.5 in the 10th instar nymph, then are 18.5 in female adult and 20.0 in male adult; spherulocytes are shown only for adults at 3.5 in female and 1.0 in male, with dashes for nymph stages. For Empusa fasciata, prohemocytes range from 30.1 in the 2nd instar nymph down to 15.4 in the 5th instar nymph, and are 15.1 in female adult and 16.6 in male adult. Plasmatocytes in Empusa fasciata stay around the low to mid 30s, from 33.1 in the 2nd instar nymph to 35.2 in the 5th instar nymph, and are 34.3 in female adult and 32.4 in male adult. Granulocytes in Empusa fasciata range from 34.0 in the 2nd instar nymph up to 41.2 in the 5th instar nymph, and are 36.2 in female adult and 35.1 in male adult. Oenocytoids in Empusa fasciata rise from 3.1 in the 2nd instar nymph to 13.0 in the 7th instar nymph, and are 15.4 in female adult and 16.0 in male adult; spherulocytes are shown as dashes for all listed stages.
Note: Different letters in each column show significance using Tukey’s test at p < 0.05.
In E. fasciata, plasmatocytes were more abundant than in H. tenuidentata across all stages. In H. tenuidentata, the frequency of plasmatocytes followed an inverse trend relative to prohemocytes. These cells were scarce in early instars but increased steadily with age, peaking at nymphal stages 9 and 10. In contrast, E. fasciata consistently exhibited high plasmatocyte frequency (30–35%) throughout all examined life stages (F = 40.5, df = 17, p ≤ 0.0001).
Granulocytes were the most abundant hemocyte type in both species and across all developmental stages (F = 63.2, df = 17, p ≤ 0.0002). Their relative abundance ranged from 32% to 46%, suggesting a consistently high level of immunological activity in both mantids.
Oenocytoids constituted approximately 5–20% of circulating hemocytes during the late nymphal and adult stages in both species, maintaining a lower average compared to other cell types (F = 22.2, df = 17, p ≤ 0.002). Spherulocytes were detected exclusively in mature individuals of H. tenuidentata, with the lowest observed frequency (1–3%).
Effect of starvation period on hemocyte reduction of H. tenuidentata and E. fasciata
According to table 3, starvation had a significant effect on THC and DHC in both H. tenuidentata and E. fasciata. In H. tenuidentata, starvation significantly affected THC (F = 780.0, df = 4, p ≤ 0.0001), prohemocytes (F = 245.3, df = 4, p ≤ 0.0001), plasmatocytes (F = 121.4, df = 4, p ≤ 0.002), granulocytes (F = 114.2, df = 4, p ≤ 0.0001), and oenocytoids (F = 45.5, df = 4, p ≤ 0.0001). In E. fasciata, similar significant effects were observed: THC (F = 815.3, df = 4, p ≤ 0.0001), prohemocytes (F = 182.2, df = 4, p ≤ 0.0001), plasmatocytes (F = 348.2, df = 4, p ≤ 0.0001), granulocytes (F = 154.2, df = 4, p ≤ 0.003), and oenocytoids (F = 15.6, df = 4, p ≤ 0.0001).
Effect of starvation period on hemocyte count of 6th instar nymph in Hierodula tenuidentata and Empusa fasciata
Table 3 Long description
Hemocyte number, reported as cells in mm3, is listed for two mantids across starvation duration in hours: control, 24, 48, 72, and 96. For H. tenuidentata, total hemocyte values are 1430 plus or minus 112.6a at control, 1388 plus or minus 88.5a at 24, 1255 plus or minus 72.2b at 48, 983 plus or minus 70.5c at 72, and 874 plus or minus 46.7d at 96. H. tenuidentata prohemocyte values are 440 plus or minus 36.5a, 421 plus or minus 22.4a, 365 plus or minus 24.3b, 352 plus or minus 38.7b, and 277 plus or minus 56.5c; plasmatocyte values are 275 plus or minus 21.6a, 250.3 plus or minus 25.5a, 210 plus or minus 24.5b, 202 plus or minus 15.6b, and 175 plus or minus 17.7c. H. tenuidentata granulocyte values are 525 plus or minus 54.3a, 512 plus or minus 36.5a, 445 plus or minus 64.3b, 366 plus or minus 35.5c, and 270 plus or minus 18.6d; oenocytoid values are 215 plus or minus 10.4a, 194 plus or minus 15.4a, 175 plus or minus 21.2a, 124 plus or minus 16.6c, and 100 plus or minus 12.3c. For E. fasciata, total hemocyte values are 1745 plus or minus 121.6a at control, 1700 plus or minus 90.5a at 24, 1652 plus or minus 104.2b at 48, 1412 plus or minus 77.5c at 72, and 976 plus or minus 90.2d at 96. E. fasciata prohemocyte values are 285 plus or minus 30a, 254.3 plus or minus 38.4a, 221.4 plus or minus 15.5a, 155.6 plus or minus 23.4b, and 115.3 plus or minus 22.4c; plasmatocyte values are 593 plus or minus 44.6a, 570 plus or minus 40.5a, 503 plus or minus 25.7b, 423 plus or minus 41.8c, and 321 plus or minus 33.7d. E. fasciata granulocyte values are 721 plus or minus 50.3a, 711 plus or minus 21.3a, 678 plus or minus 34.2b, 604 plus or minus 51.6c, and 518 plus or minus 24.2d; oenocytoid values are 136 plus or minus 12.4a, 128 plus or minus 15.6a, 112 plus or minus 10b, 94 plus or minus 17.4c, and 56 plus or minus 8.7d. Each value includes a trailing letter marker shown in the cells.
Note: Different letters in each row show significance using Tukey’s test at p < 0.05.
In both species, hemocyte counts after 24 hours of starvation did not differ significantly from the control group. However, with prolonged starvation (48 and 72 hours), all hemocyte types declined progressively. The most pronounced reduction occurred at 96 hours, where the lowest levels of THC, granulocytes, plasmatocytes, and oenocytoids were recorded.
In H. tenuidentata, granulocyte number in nymphs starved for 4 days were approximately half those of the control group. In E. fasciata, THC, prohemocyte, and plasmatocyte counts also dropped to nearly 50% of control values after 96 hours of starvation. These findings underscore the critical role of daily nutritional intake in maintaining hemocyte populations. Notably, hemocyte depletion became after 48 hours of food deprivation in both species.
Effect of prey type on hemocyte changes of H. tenuidentata and E. fasciata
According to table 4, diet significantly influenced THC and DHC in both H. tenuidentata and E. fasciata during the 7-day feeding period. In H. tenuidentata, significant effects were observed on THC (F = 824.4, df = 5, p ≤ 0.0001), prohemocytes (F = 145.5, df = 5, p ≤ 0.0001), plasmatocytes (F = 132.2, df = 5, p ≤ 0.0002), granulocytes (F = 246.6, df = 5, p ≤ 0.0001), and oenocytoids (F = 57.6, df = 5, p ≤ 0.0001). Similarly, in E. fasciata, diet had a significant effect on THC (F = 921.3, df = 5, p ≤ 0.0001), prohemocytes (F = 211.2, df = 5, p ≤ 0.0001), plasmatocytes (F = 214.5, df = 5, p ≤ 0.0001), granulocytes (F = 286.5, df = 5, p ≤ 0.0001), and oenocytoids (F = 32.2, df = 5, p ≤ 0.0001).
Effect of prey on hemocyte count of 6th instar nymph in Hierodula tenuidentata and Empusa fasciata
Table 4 Long description
Hemocyte number, reported as cells per mm3 with mean plus or minus variation and letter markers, is listed for two mantids across six prey types: Musca domestica, Lycaena sp., Tenebrio molitor, Plodia interpunctella, Oedipoda sp., and Dociostaurus maroccanus. For H. tenuidentata, total hemocyte values are 1288, 1330, 1384, 1421, 1883, and 1812; prohemocyte values are 355.5, 378.3, 411, 377, 523, and 434.6; plasmatocyte values are 231.5, 283.4, 270, 286, 576, and 550.4; granulocyte values are 444, 415.5, 488, 506, 655, and 702; oenocytoid values are 170, 154.3, 176, 128, 214, and 178. For E. fasciata, total hemocyte values are 1421, 1543, 1655, 1843, 2124, and 2235; prohemocyte values are 150, 166, 230, 321.3, 365.6, and 333.6; plasmatocyte values are 488, 521, 575, 681.4, 825, and 872.4; granulocyte values are 631.3, 615, 657, 810.6, 1066, and 1120; oenocytoid values are 72.5, 70.5, 88.5, 118.5, 194.5, and 176. Letter markers appear after each mean value in every row.
Different letters in each row show significance using Tukey’s test at p < 0.05.
Hemocyte counts – particularly THC, plasmatocytes, and granulocytes – were significantly higher in mantids fed on nymphs of Oedipoda sp. and D. maroccanus compared with other prey types. In E. fasciata, the highest hemocyte number was observed after feeding of grasshoppers (Oedipoda sp., Dociostaurus maroccanus, and P. interpunctella), respectively. In H. tenuidentata, granulocytes and prohemocytes consistently exhibited higher densities than other hemocyte types across all treatments. In E. fasciata, granulocytes and plasmatocytes were the most abundant regardless of diet.
These findings suggest a sustained enrichment of circulating immunocytes in both species, indicating that diet composition modulates – but does not override – their inherently active cellular defence systems.
Effect of thermal stress on hemocyte reduction or elevation of H. tenuidentata and E. fasciata
Temperature stresses significantly affected hemocyte composition in H. tenuidentata (table 5). THC (F = 631.4, df = 4, p ≤ 0.0001), prohemocytes (F = 215.5, df = 4, p ≤ 0.0001), plasmatocytes (F = 153.8, df = 4, p ≤ 0.001), granulocytes (F = 135.3, df = 4, p ≤ 0.0001), and oenocytoids (F = 43.2, df = 4, p ≤ 0.002) either increased or decreased depending on the duration and type of thermal exposure. After 24 hours of heat stress, granulocyte number increased (540 ± 46.2 cells in mm3) compared with the control (515.4 ± 50.2 cells in mm3), while other hemocyte types remained essentially unchanged. After 48 hours, THC, plasmatocytes, and granulocytes increased, whereas prohemocytes declined. Oenocytoids showed no significant changes under either heat exposure condition. Cold stress also induced significant alterations. Following 24 and 48 hours of exposure to 5°C, THC and all hemocyte subtypes decreased markedly compared with the control, with a greater reduction observed after 48 hours.
Effect of thermal stress on hemocyte count of 5th instar nymph in Hierodula tenuidentata and Empusa fasciata
Table 5 Long description
Hemocyte number, cells in mm3, is listed for two mantids across Temperature, degrees Celsius, conditions: Control, Heat 24 h, Heat 48 h, Cold 24 h, and Cold 48 h. For H. tenuidentata, total hemocyte is 1334 plus or minus 85.6 at Control, 1321.5 plus or minus 95.6 at Heat 24 h, 1555.5 plus or minus 110 at Heat 48 h, 1222 plus or minus 74.5 at Cold 24 h, and 977 plus or minus 45.5 at Cold 48 h. H. tenuidentata prohemocyte is 450.4 plus or minus 23.5, 461.3 plus or minus 32.6, 407.3 plus or minus 25.6, 404.1 plus or minus 34.6, and 356.1 plus or minus 26.8 across the same columns. H. tenuidentata plasmatocyte is 227 plus or minus 34.7, 215.6 plus or minus 14.7, 352.6 plus or minus 26.5, 188.7 plus or minus 16.3, and 112 plus or minus 14.5; granulocyte is 515.4 plus or minus 50.2, 540 plus or minus 46.2, 634.5 plus or minus 28.2, 465.1 plus or minus 38.6, and 370 plus or minus 42.4; oenocytoid is 145.3 plus or minus 27.3, 135 plus or minus 15, 157 plus or minus 16.5, 115.6 plus or minus 10.5, and 103.3 plus or minus 17.5. For E. fasciata, total hemocyte is 1715 plus or minus 151.6 at Control, 1734 plus or minus 130.6 at Heat 24 h, 1763 plus or minus 114.8 at Heat 48 h, 1690 plus or minus 106.6 at Cold 24 h, and 1578 plus or minus 132.3 at Cold 48 h. E. fasciata prohemocyte is 254 plus or minus 36.6, 260.3 plus or minus 45.3, 273 plus or minus 21.6, 248 plus or minus 25.6, and 225 plus or minus 53.6; plasmatocyte is 561 plus or minus 23.2, 537.4 plus or minus 45.2, 555 plus or minus 43.2, 548 plus or minus 41.2, and 544.3 plus or minus 37.2. E. fasciata granulocyte is 711.7 plus or minus 61.6, 724.4 plus or minus 35.6, 744.7 plus or minus 56.8, 684.7 plus or minus 52.6, and 603.5 plus or minus 71.5; oenocytoid is 107 plus or minus 8.3, 88 plus or minus 15.3, 92.5 plus or minus 12.3, 91.4 plus or minus 12.3, and 75.4 plus or minus 6.7. Each value includes a trailing letter in the cell, and the Heat and Cold columns include an asterisk marker in their headers.
Notes: Different letters in each row show significance using Tukey’s test at p < 0.05.
* Heat: 30℃.
* Cold: 5℃.
Table 5 summarises hemocyte responses in E. fasciata under thermal stress. THC (F = 914.4, df = 4, p ≤ 0.0001), prohemocytes (F = 86.3, df = 4, p ≤ 0.0001), plasmatocytes (F = 110.4, df = 4, p ≤ 0.0001), granulocytes (F = 155.4, df = 4, p ≤ 0.0001), and oenocytoids (F = 35.6, df = 4, p ≤ 0.001) exhibited significant fluctuations after exposure to 30°C and 5°C at both 24 and 48 hours. No substantial change was observed after 24 hours of heat exposure, but 48-hour treatment resulted in increased granulocytes and a corresponding rise in THC. In contrast, cold exposure for 24 hours significantly reduced granulocytes (684.7 ± 52.6 cells in mm3) and THC (1690 ± 106.6 cells in mm3). These effects intensified after 48 hours, indicating that prolonged cold stress more severely disrupted hemocyte profiles and circulatory regulation in E. fasciata.
Discussion
Although faunistic investigations of mantids in Iran remain limited in scope, previous reports have documented the presence of Hierodula tenuidentata and Empusa fasciata in several provinces, including northern regions along the humid Caspian Sea coast, western temperate mountainous zones, and southern provinces characterised by warm and temperate climates (Mirzaee and Pashaie Rad, Reference Mirzaee and Pashaie Rad2017; Mirzaee and Sadeghi, Reference Mirzaee and Sadeghi2019, Reference Mirzaee and Sadeghi2021). In the current study, both nymphs and adults of H. tenuidentata and E. fasciata were collected from orchards and rangelands within Semnan Province, a region classified as hot and arid. The occurrence of these species across diverse climatic zones of Iran underscores their considerable adaptability to varying thermal environments. Given that the insect prey base of mantids also shifts with climatic variability, these findings highlight the ecological significance and dietary flexibility of H. tenuidentata and E. fasciata across Iran. Despite the ecological importance of these species, investigations into their hemocyte profiles and associated physiological responses to environmental and nutritional stressors have been extremely limited. This study characterises the hemocyte patterns and diversity across developmental stages of both species, elucidating how hemocyte composition is modulated by food scarcity and temperature fluctuations. Moreover, understanding the immune physiology of these mantids offers valuable insights into their biological resilience, ecological interactions, and trophic dynamics.
The hemolymph of H. tenuidentata and E. fasciata contained abundant hemocytes across all developmental stages, as observed through Giemsa staining. Even 1–2 μL of hemolymph consistently yielded high cellular counts, including prohemocytes, plasmatocytes, granulocytes, and oenocytoids. Spherulocytes, the fifth hemocyte type, were detected exclusively in adult H. tenuidentata. All five types have previously been reported in Blepharopsis mendica Fabricius (Mantodea: Empusidae) (Ajamhassani and Ahangi Rashti, Reference Ajamhassani and Ahangi Rashti2020). These hemocytes are common across insect taxa, with granulocytes and plasmatocytes playing primary roles in immune defence (Strand and Pech, Reference Strand and Pech1995; Lavine and Strand, Reference Lavine and Strand2002; Abdos et al., Reference Abdos, Ajamhassani and Zamani2025; Ajamhassani et al., Reference Ajamhassani, Abdos and El Aalaoui2026). Hemocyte size differed markedly between the two species. Cells in E. fasciata were approximately half the size of those in H. tenuidentata. Larger granulocytes and plasmatocytes are generally more effective in confronting foreign agents (Tojo et al., Reference Tojo, Naganuma, Arakawa and Yokoo2000; Beckage, Reference Beckage2008). Increased cytoplasmic granulation in granulocytes or elongated pseudopodia in plasmatocytes facilitate phagocytosis and nodule formation, promoting encapsulation and destruction of invaders (Akai and Sato, Reference Akai and Sato1973; Tanaka and Yamakawa, Reference Tanaka and Yamakawa2011). These morphological advantages may enhance the stress resilience of H. tenuidentata hemolymph.
We observed varying densities of hemocytes at different developmental stages. Although experiments were conducted under controlled conditions to minimise stress, the role of prey health and the absence of contamination with toxins or fungal and bacterial spores should not be overlooked in immune interactions. Granulocytes in H. tenuidentata and both granulocytes and plasmatocytes in E. fasciata showed the highest densities across all life stages. Oenocytoids and prohemocytes exhibited variable abundance depending on the stage. In young nymphs of both mantids, prohemocyte counts exceeded those of oenocytoids. Prohemocytes function as stem-like precursors that differentiate into immune effector cells in response to stress or pathogen invasion (Yamashita and Iwabuchi, Reference Yamashita and Iwabuchi2001). The reduced number of prohemocytes in older larvae and adults compared to early instars may indicate their transition into granulocytes, which are essential for phagocytosis and nodulation of foreign agents. It is proved that the prohemocyte can differentiate into other cell types (Strand, 2008). These developmental shifts in hemocyte composition may be associated with feeding patterns, thermal stress, moulting, or pathogen exposure (Vogelweith et al., Reference Vogelweith, Moret, Monceau, Thieri and Moreau2016). Additionally, nutritional content and hormonal status contribute to stage-specific variation in hemocyte density (Gupta, Reference Gupta and Gupta1991). Immune responses in early instars tend to be weaker, suggesting that hemocyte proliferation and differentiation become more prominent in later stages (Brodeur and Vet, Reference Brodeur and Vet1995; Gillespie et al., Reference Gillespie, Kanost and Trenczek1997). For instance, in Bombyx mori (Linnaeus, 1758), both hemocyte adhesion and phagocytosis increase with larval age (Wago and Ichikawa, Reference Wago and Ichikawa1979).
Short-term starvation and dietary variation significantly affected hemocyte abundance in both H. tenuidentata and E. fasciata. Extended food deprivation resulted in a marked reduction in circulating hemocytes. After 96 hours of starvation, counts of total hemocytes, granulocytes, and plasmatocytes were at their lowest. These findings emphasise the critical role of continuous nutrition and macromolecules in maintaining circulatory immune function in mantids like to another Arthropoda (Lee et al., Reference Lee, Simpson and Wilson2008; Maklakov et al., Reference Maklakov, Simpson, Zajitschek, Hall, Dessmann and Clissold2008; Graham et al., Reference Graham, Deacutis, Pulpitel, Ponton, Simpson and Wilson2014). The physiological impact of undernourishment was evident, as individuals subjected to 4 days of starvation died shortly after their first moult (unpublished data), highlighting the necessity of daily feeding for survival. A strong correlation has been reported between nutritional status and physiological performance in T. angustipennis (Mantodea: Mantidae), where starved third- and fifth-instar nymphs exhibited significant weight loss and reduced metabolic activity compared to their well-fed counterparts (Matsura, Reference Matsura1981). Starvation also impairs reproductive traits, including male courtship, female receptivity, and mating duration (Scharaf, Reference Scharaf2016). Previous studies have demonstrated that food restriction leads to a reduction in hemolymph volume and, consequently, a lower hemocyte density. In P. interpunctella, 24–72 hours of food deprivation caused a measurable decline in hemocyte numbers (Ebrahimi and Ajamhassani, Reference Ebrahimi and Ajamhassani2020). Similarly, in Galleria mellonella (Linnaeus, 1758), reduced hemocyte density was reported in response to Candida albicans (C.-P.Robin) Berkhout, 1923 infection under starvation conditions (Banville et al., Reference Banville, Browne and Kavanagh2012).
In this study, sixth-instar mantids were fed various prey for 7 days, including adults of M. domestica, P. interpunctella, and Lecaena sp., nymphs of D. maroccanus and Oedipoda sp., and larvae of T. molitor. Hemocyte abundance varied significantly with prey type, with the highest counts observed in H. tenuidentata feeding on D. maroccanus and Oedipoda sp., and in E. fasciata fed on P. interpunctella and grasshoppers. These results support previous studies showing that diet quality influences insect immune cell profiles (Manjula et al., Reference Manjula, Lalitha and Shivakumar2020). Similar effects have been reported in Cydalima perspectalis (Walker, 1859) (Lepidoptera: Crambidae) larvae reared on different host cultivars (Kholghahmadi et al., Reference Kholghahmadi, Karimi-Malati and Jalali Sendi2025) and in Hyposidra talaca (Walker, 1860) (Lepidoptera: Geometridae) larvae fed protein-rich artificial diets (Ghosh et al., Reference Ghosh, Prasad and Mukhopadhyay2018). Grasshoppers likely provide greater nutritional value due to higher protein and lipid content, which may contribute to the increased hemocyte abundance observed. Although larger prey generally offer greater energetic returns, they also require greater handling effort, and according to optimal foraging theory predators tend to select prey that maximises net energy gain (Maxwell and Eitan, Reference Maxwell and Eitan1998; Chong, Reference Chong2002; Maxwell and Frinchaboy, Reference Maxwell and Frinchaboy2014). Mantids typically capture prey smaller than half their body size (Reitze and Nentwig, Reference Reitze and Nentwig1991); accordingly, all prey used in this study were ≤1 cm and within the preferred size range for sixth-instar mantids. In addition to prey size, prey quality and physical characteristics may influence feeding efficiency and physiological responses. Observations showed that H. tenuidentata and E. fasciata selectively consumed the abdomen of Lecaena sp., avoiding the wings, suggesting prey-part selection based on nutritional value or digestibility. The relatively small size of M. domestica may correspond to lower nutritional value, while the tough, sclerotized cuticle of T. molitor larvae may reduce digestibility compared with softer-bodied prey such as grasshoppers. Similar limitations have been reported for beetles with hard exoskeletons, which can reduce feeding efficiency in mantids (Reitze and Nentwig, Reference Reitze and Nentwig1991). Overall, these results indicate that both prey nutritional value and physical structure influence prey suitability and may affect immune-related physiological responses such as hemocyte abundance in predatory insects.
Prey nutrition directly influences the extent of consumption by predators. This interaction reflects an ecologically realistic scenario, where the prey’s nutritional state – shaped by its diet – affects predator intake. In this study, all prey items except P. interpunctella and T. molitor were collected from field environments (rangelands of Shahrood region in Semnan Province). Previous work has shown that spiders consuming well-fed crickets ingested approximately 15% more lipids than those consuming starved individuals (Wilder et al., Reference Wilder, Mayntz, Toft, Rypstra, Pilati and Vanni2010). Similarly, Orius (Hemiptera: Anthocoridae) adults produced more eggs when fed on Drosophila reared on a protein-rich casein diet compared to those reared on a sucrose-based diet (Montoro et al., Reference Montoro, De Fine Licht and Sigsgaard2021). Environmental factors such as habitat richness and interspecific competition can indirectly influence prey nutritional quality. Korichi et al. (Reference Korichi, Ould El Hadj, Doumadji, Bia and Tartoura2016) demonstrated that predators in heterogeneous habitats encounter more diverse and potentially better-nourished prey. In the current study, H. tenuidentata was observed in a range of habitats, including gardens, urban green zones, and mountain slopes, whereas E. fasciata was largely confined to arid shrublands and semi-desert terrains. These ecological differences may underlie the contrasting prey utilisation patterns between the two mantid species (Baranowski, Reference Baranowski2025).
Notably, the rangelands of the Shahrood region support abundant herbaceous plants and gramineae, especially in spring. Located away from human traffic routes, they remain free from pesticide applications or other control measures. A diverse array of grasshoppers and Lepidoptera feed on these plants, and these insects likely had access to adequate nutrition before predation. The adequate abundance of prey in these rangelands suggests that mantids in such habitats can prefer prey grasshoppers and Lepidoptera through active foraging. At the same time, mantids readily accepted and consumed the laboratory-reared prey, P. interpunctella and T. molitor. Changes in hemocyte density in both mantid species were greater when fed field-collected prey than when fed laboratory-reared prey. However, targeted field investigations are required to confirm whether habitat variability consistently translates to prey quality differences and subsequent immunophysiological outcomes.
Thermal extremes at 30°C and 5°C induced significant changes in hemocyte density in H. tenuidentata and E. fasciata within 48 hours of exposure. In H. tenuidentata nymphs, 30°C heat stress resulted in a marked reduction in prohemocyte numbers and a concurrent increase in granulocyte and plasmatocyte counts. A similar increase in granulocytes and plasmatocytes was observed in E. fasciata nymphs after 48 hours of heat exposure. These results support the hypothesis that prohemocytes, as undifferentiated precursors, undergo mitotic division into more specialised hemocyte types – particularly granulocytes – under stress conditions, thereby explaining their reduction (Pandey et al., Reference Pandey, Mishra, Kumar, Singh and Prasad2010). Cold exposure at 5°C elicited immunological responses in both species, notably affecting granulocyte and plasmatocyte densities. In H. tenuidentata, a decline in total hemocytes was apparent after just 24 hours, with further reductions at 48 hours. In E. fasciata, cold-induced granulocyte depletion was evident at 24 hours, whereas changes in other hemocytes occurred more gradually, becoming significant after 48 hours. By the end of the cold stress period, the THC and all individual hemocyte types had declined significantly compared to the control group. These reductions are likely attributable to decreased feeding under low-temperature conditions, which are suboptimal for mantid physiological activity. Most mantids remain active within a thermal window of 20–30°C (Prete et al., Reference Prete, Wells, Wells and Hurd1999; Battiston et al., Reference Battiston, Picciau, Fontana and Marshall2010), which represents the optimal range for their physiological functioning and behavioural repertoire. Within this interval, mantids exhibit maximal locomotor activity, efficient predation, mating behaviour, and egg-laying. Activity levels tend to increase with temperature up to a point, but exposure to temperatures beyond this upper threshold can lead to thermal stress, reduced mobility, and eventual mortality (Schmalhofer, Reference Schmalhofer1999). Conversely, temperatures below this range are often suboptimal or detrimental, particularly to early instars and developing oothecae. Under such cool conditions, mantids may enter a near-quiescent state, with significant reductions in movement and foraging efficiency. Both laboratory and field observations have shown that low temperatures can delay moulting, interfere with nutrient assimilation, and lower survival and reproductive success rates (Hurd et al., Reference Hurd, Eisenberg, Moran, Rooney, Gangloff and Case1995; Prete et al., Reference Prete, Wells, Wells and Hurd1999). Nutritional deprivation due to extreme temperature fluctuations not only reduces hemocyte proliferation but may also trigger the transition of circulating hemocytes into a sessile state. Another reason for the change in the number of cells is that sometimes the cells are damaged or destroyed due to stress tolerance (Johansson et al., Reference Johansson, Keyser, Sritunyalucksana and Söderhäll2000; Jiravanichpaisal et al., Reference Jiravanichpaisal, Lee and Söderhäll2006). Previous studies corroborate these findings, with similar hemocyte responses reported in other insects. In Danaus chrysippus (Linnaeus, 1758) (Lepidoptera: Danaidae), cold stress reduced hemocyte numbers, while heat increased them (Pandey et al., Reference Pandey, Tiwari and Kumar2008). Under cold stress, the number of hemocyte in Nicrophorus vespilloides Herbst, 1783 (Coleoptera: Silphidae) decreased and percentage ratio of phagocytic hemocyte reduced (Urbanski et al., Reference Urbanski, Czarniewska, Baraniak and Rosinski2017). In Dacus ciliatus Loew, 1862 (Diptera: Tephritidae), both heat (30°C) and cold (4°C) elevated THCs, cold thermal stress reduced granulocyte and plasmatocyte counts (Ajamhassani et al., Reference Ajamhassani, El Aaalaoui and Valizadeh2025).
Conclusion
Nutritional status and thermal stress exerted a marked influence on the hemocyte number of H. tenuidentata and E. fasciata. Starvation periods up to 96 hours significantly reduced circulating hemocytes, while diet quality and thermal extremes modulated hemocyte abundance across both species. The findings suggest that mantid immunity is acutely sensitive to short-term nutritional deprivation and temperature fluctuations. Predators deprived of sufficient or high-quality prey may become physiologically compromised and more susceptible to environmental pressures. Similarly, even brief exposures to suboptimal temperatures appear capable of impairing cellular immune responses.
Given the ecological relevance of mantids as generalist predators and their contribution to arthropod population control, optimising conditions for their survival – particularly in conservation or mass-rearing programs – requires a comprehensive understanding of their physiological resilience. Hemocyte profiling provides a valuable lens through which to examine immune function and circulatory adaptations in response to abiotic and dietary stressors. These findings establish a foundation for future research in mantid immunophysiology and may inform efforts to enhance their application in biological control frameworks.
Supplementary material
The supplementary material for this article can be found at https://doi.org/10.1017/S0007485326100984.
Acknowledgements
The authors express their gratitude to Mr Mehdi Tork (University of Tehran) for his assistance in identifying nymphal specimens of D. maroccanus and Oedipoda sp. and express special appreciation to the Shahrood University of Technology for their scientific support and help. We also thank the editorial office of Bulletin of Entomological Research for handling our manuscript.
Financial support
This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.
