Types Of Hemocytes Research Articles

English

Haemocytes in insects mediates the cellular responses like phagocytosis, encapsulation and clotting which signifies the immunological functions of any insect. In the domesticated variety of silkworm B.mori five types of haemocytes have been identified in all the stages. The most abundant cell was found to be plasmatocytes followed by Granular cells. Spherule cells and Oenocytoids were found to less during IV and V instars and least or absent in all other stages. Haemocytes found be to fluctuating before and after spinning. Plasmatocytes and granular cells decreased gradually with respect to number of days in pupa. The total haemocytic count increases gradually in the silkworm larval stages and found to be maximum at the last instar and least during adult stages where the role of haemocytes is not required because they die after laying eggs.

Morphological and Ultrastructural Characterization of Hemocytes in an Insect Model, the Hematophagous Dipetalogaster maxima (Hemiptera: Reduviidae).

Simple SummaryChagas’ disease is a debilitating and life-threatening disease endemic of the Americas, although it currently affects about six to seven million people around the world. The triatomines, also known as kissing bugs, are blood-feeding insects that play a key role in the transmission of Chagas’ disease since they are the vectors of the parasite Trypanosoma cruzi, the causative agent of the illness. On the other hand, the hemocytes are the cells present in the circulatory system of insects and other invertebrates. These cells are comparable to the white blood cells of vertebrates and fulfill vital functions in coagulation and defense against pathogens. The classification of hemocytes is mainly based in their cell shape, which is technically challenging to assess, and the authors have not always agreed upon this subject. In this study we combined different techniques to classify the hemocytes of the kissing bug Dipetalogaster maxima in a juvenile stage of development. We characterized the hemocytes in five types, including plasmatocytes, granulocytes, prohemocytes, adipohemocytes and oenocytes. These findings contribute to the understanding of insect and triatomine physiology and can be applied to unravel basic aspects of insect immune responses, coagulation cascades and endocrine processes.Hemocytes, the cells present in the hemolymph of insects and other invertebrates, perform several physiological functions, including innate immunity. The current classification of hemocyte types is based mostly on morphological features; however, divergences have emerged among specialists in triatomines, the insect vectors of Chagas’ disease (Hemiptera: Reduviidae). Here, we have combined technical approaches in order to characterize the hemocytes from fifth instar nymphs of the triatomine Dipetalogaster maxima. Moreover, in this work we describe, for the first time, the ultrastructural features of D. maxima hemocytes. Using phase contrast microscopy of fresh preparations, five hemocyte populations were identified and further characterized by immunofluorescence, flow cytometry and transmission electron microscopy. The plasmatocytes and the granulocytes were the most abundant cell types, although prohemocytes, adipohemocytes and oenocytes were also found. This work sheds light on a controversial aspect of triatomine cell biology and physiology setting the basis for future in-depth studies directed to address hemocyte classification using non-microscopy-based markers.

Effects of Zinc oxide Nanoparticles (ZnO NPs) on Hemocyte Types of Galleria mellonella

In this study, 70 nm-sized and nanorod-shaped Zinc oxide nanoparticle (ZnO NPs) concentrations (0.5, 1, 2.5, 5, and 10 µg/10 µl) was force-fed to fourth instar (110 ± 20 mg) Galleria mellonella (Lepidoptera: Pyralidae) larvae. The effects of ZnO NPs on plasmatocyte, granulocyte, spherulocyte, prohemocyte, oenocytoid, and coagulocyte numbers in hemolymph of G. mellonella larvae was determined. Results showed that treating G. mellonella with 10 μg/10 µl ZnO NPs significantly decreased spherulocytes numbers, whereas numbers of plasmatocyte, granulocyte, prohemocyte, oenocytoid, and coagulocyte numbers did not differ significantly when compared to the control group after 24 h force feeding treatment. There was a statistically significant difference between the experimental groups in the prohemocyte numbers of larvae that exposed to 1 and 5 μg/10 µl ZnO NPs.

Crayfish hemocytes develop along the granular cell lineage

Despite the central role of hemocytes in crustacean immunity, the process of hemocyte differentiation and maturation remains unclear. In some decapods, it has been proposed that the two main types of hemocytes, granular cells (GCs) and semigranular cells (SGCs), differentiate along separate lineages. However, our current findings challenge this model. By tracking newly produced hemocytes and transplanted cells, we demonstrate that almost all the circulating hemocytes of crayfish belong to the GC lineage. SGCs and GCs may represent hemocytes of different developmental stages rather than two types of fully differentiated cells. Hemocyte precursors produced by progenitor cells differentiate in the hematopoietic tissue (HPT) for 3 ~ 4 days. Immature hemocytes are released from HPT in the form of SGCs and take 1 ~ 3 months to mature in the circulation. GCs represent the terminal stage of development. They can survive for as long as 2 months. The changes in the expression pattern of marker genes during GC differentiation support our conclusions. Further analysis of hemocyte phagocytosis indicates the existence of functionally different subpopulations. These findings may reshape our understanding of crustacean hematopoiesis and may lead to reconsideration of the roles and relationship of circulating hemocytes.

Acute hypoxic exposure: Effect on hemocyte functional parameters and antioxidant potential in gills of the pacific oyster, Crassostrea gigas

Bivalve mollusks are frequently subjected to fluctuations of dissolved oxygen concentration in the environment which can represent a significant threat to bivalve antioxidant status. In this work the effects of hypoxia on hemocyte reactive oxygen species (ROS) production and level of mitochondrial potential as well as the activity and expression level of catalase (CAT) and superoxide dismutase (SOD) in gills of Crassostrea gigas were investigated after 24 h and 72 h exposure. 24 h hypoxia promoted an increase of mitochondrial membrane potential in agranulocytes and induced ROS accumulation in granulocytes. 72 h exposure substantially decreased hemocyte mitochondrial potential and intracellular ROS level in all hemocyte types. No significant changes in the activity of CAT in gills were observed following both 24 h and 72 h exposure periods compared to control. SOD activity in gills decreased after 72 h exposure to hypoxia but did not change under 24 h hypoxia. Significant up-regulation of SOD gene and no changes in expression level of CAT were observed in all experimental groups. The results indicate an overall shift in antioxidant status in gills and hemocytes of the Pacific oyster that may act as compensatory mechanisms to maintain redox homeostasis after a short-term (24 h) exposure and represent the occurrence of oxidative stress conditions at the end of 72 h hypoxia.

Flow cytometric analysis of morphologic and immunological characterisation of the tiger shrimp Penaeus monodon haemocytes

Morphology and immune functions of Penaeus monodon haemocytes were analysed by flow cytometry (FCM). Basing on the relative size and granularity, there are three types of haemocyte identified by FCM, including hyaline cells (HC), semigranular cells (SGC) and granular cells (GC). GC and SGC were significantly larger than HC. GC contained more granules in the cytoplasm than the two other types. SGC were the most abundant cells, while HC were the least. The mean total apoptotic cell ratio was 5.09 % in the fresh shrimp haemocytes. SGC contributed most to the phagocytic activity, and HC contributed least, probably due to the great difference of percentage. GC had most mass of mitochondria and lysosome, and HC contained least. Defined by different characteristic of lysosomal mass, three subsets of haemocytes were observed. GC were most active in non-induced and zymosan-induced reactive oxygen species (ROS) production, while HC showed lowest oxidative activity. Both non-induced and zymosan-induced esterase activity (EA) in GC were higher than those in SGC and HC. The present flow cytometric analysis clearly demonstrated the variation in morphologic and immunological characterisation among the three haemocyte subpopulations. The facts that SGC account for most of the number of circulating haemocyte, while GC contain most organelles in relation to energy supply and immune defence, and have highest immune activites, suggesting that GC and SGC are the main haemocyte types involved in the cellular defence of P. monodon.

Single-cell RNA-seq analysis reveals penaeid shrimp hemocyte subpopulations and cell differentiation process.

Crustacean aquaculture is expected to be a major source of fishery commodities in the near future. Hemocytes are key players of the immune system in shrimps; however, their classification, maturation, and differentiation are still under debate. To date, only discrete and inconsistent information on the classification of shrimp hemocytes has been reported, showing that the morphological characteristics are not sufficient to resolve their actual roles. Our present study using single-cell RNA sequencing revealed six types of hemocytes of Marsupenaeus japonicus based on their transcriptional profiles. We identified markers of each subpopulation and predicted the differentiation pathways involved in their maturation. We also predicted cell growth factors that might play crucial roles in hemocyte differentiation. Different immune roles among these subpopulations were suggested from the analysis of differentially expressed immune-related genes. These results provide a unified classification of shrimp hemocytes, which improves the understanding of its immune system.

Morphological and Functional Characterization of Hemocytes of the Black Sea Bivalves: Pacific Oyster (Crassostrea gigas) and Mussel (Mytilus galloprovincialis)

To understand the role that hemocytes play in processes of cellular immunity of bivalve mollusks, they should be accurately classified based on their morphological and physiological characteristics. The circulating hemocytes of the cultured Pacific oyster (Crassostrea gigas) and marine mussel (Mytilus galloprovincialis) were investigated using light microscopy and flow cytometry. In the mussel, two cell types, granulocytes and agranulocytes, were identified based on the presence of two subpopulations of cells differing by size and granularity level on light scatter plots. Light microscopic examination confirmed the presence of cells with cytoplasmic granules and cells without granulation in hemolymph of the mussel. In the oyster, light microscopy and flow cytometry revealed three types of hemocytes: agranulocytes, hyalinocytes, and granulocytes. The cells in the hemolymph of both species were mainly represented by agranular cells, which constituted 78.4 ± 8.9 % in the mussel and 86.7 ± 2.7 % (agranulocytes and hyalinocytes) in the oyster. Agranulocytes were the smallest cell type in the mussel and oyster. They were round-shaped and had large nuclei and narrow cytoplasm. Hyalinocytes of the oyster were larger and irregularly shaped, with eccentric nuclei. Granulocytes of both species contained numerous eosinophilic, basophilic, and mixed granules and formed pseudopodia. Flow cytometry showed that the agranular hemocytes of both species produced considerably fewer reactive oxygen species compared to granulocytes. Morphological and functional characterization of hemocytes of cultivated species improves the analysis of physiological state of bivalve mollusks farmed in the Black Sea region

Proteomics of purified lamellocytes from Drosophila melanogaster HopTum-l identifies new membrane proteins and networks involved in their functions

In healthy Drosophila melanogaster larvae, plasmatocytes and crystal cells account for 95% and 5% of the hemocytes, respectively. A third type of hemocytes, lamellocytes, are rare, but their number increases after oviposition by parasitoid wasps. The lamellocytes form successive layers around the parasitoid egg, leading to its encapsulation and melanization, and finally the death of this intruder. However, the total number of lamellocytes per larva remains quite low even after parasitoid infestation, making direct biochemical studies difficult. Here, we used the HopTum-l mutant strain that constitutively produces large numbers of lamellocytes to set up a purification method and analyzed their major proteins by 2D gel electrophoresis and their plasma membrane surface proteins by 1D SDS-PAGE after affinity purification. Mass spectrometry identified 430 proteins from 2D spots and 344 affinity-purified proteins from 1D bands, for a total of 639 unique proteins. Known lamellocyte markers such as PPO3 and the myospheroid integrin were among the components identified with specific chaperone proteins. Affinity purification detected other integrins, as well as a wide range of integrin-associated proteins involved in the formation and function of cell-cell junctions. Overall, the newly identified proteins indicate that these cells are highly adapted to the encapsulation process (recognition, motility, adhesion, signaling), but may also have several other physiological functions (such as secretion and internalization of vesicles) under different signaling pathways. These results provide the basis for further in vivo and in vitro studies of lamellocytes, including the development of new markers to identify coexisting populations and their respective origins and functions in Drosophila immunity.

Characterization of the immune hemocyte in larvae of Dorcus titanus castanicolor (Motschulsky, 1861) (Lucanidae, Coleoptera)

AbstractThere are four types of hemocytes in the stag beetle hemolymph: granulocytes, prohemocytes, coagulocytes, and spherulocytes. Unusually, the size and shape of the hemocyte subtypes are similar. To identify the predominant immune hemocytes, we injected carboxylate‐modified polystyrene latex beads and E. coli particles into the hemocoel of stag beetles. In response to the pathogens, only granulocytes underwent morphological changes, including the extension of fan (or amoeba)‐like structures from their membrane, and had bacterial particles in their cytoplasm. At 6 h post‐injection, lysosomes in the cytoplasm of the granulocytes were activated to remove the pathogens. At 12 h post‐injection, more lysosomes were activated along with phagocytosis of the E. coli particles. At 24 h to 48 h post‐injection, the bacterial particles, including activated lysosomes, were gradually cleared from the cytoplasm. To confirm these results, we performed flow cytometry analysis. Consistent with our microscope observations, the granulocytes were activated after 6 h post‐infection, and lysosomes were mostly activated at 12 h. These results suggest that bacteria are actively engulfed between 6 and 12 h post‐infection by granulocytes. Granulocyte lysosomes were activated within 12 h to digest the bacteria, which were completely cleared by 48 h post‐infection.

Identification of Silkworm Hemocyte Subsets and Analysis of Their Response to Baculovirus Infection Based on Single-Cell RNA Sequencing.

A wide range of hemocyte types exist in insects but a full definition of the different subclasses is not yet established. The current knowledge of the classification of silkworm hemocytes mainly comes from morphology rather than specific markers, so our understanding of the detailed classification, hemocyte lineage and functions of silkworm hemocytes is very incomplete. Bombyx mori nucleopolyhedrovirus (BmNPV) is a representative member of the baculoviruses and a major pathogen that specifically infects silkworms (Bombyx mori) and causes serious losses in sericulture industry. Here, we performed single-cell RNA sequencing (scRNA-seq) of hemocytes in BmNPV and mock-infected larvae to comprehensively identify silkworm hemocyte subsets and determined specific molecular and cellular characteristics in each hemocyte subset before and after viral infectmadion. A total of 20 cell clusters and their potential marker genes were identified in silkworm hemocytes. All of the hemocyte clusters were infected by BmNPV at 3 days after inoculation. Interestingly, BmNPV infection can cause great changes in the distribution of hemocyte types. The cells appearing in the infection group mainly belong to prohemocytes (PR), while plasmatocytes (PL) and granulocytes (GR) are very much reduced. Furthermore, we found that BmNPV infection suppresses the RNA interference (RNAi) and immune response in the major hemocyte types. In summary, our results revealed the diversity of silkworm hemocytes and provided a rich resource of gene expression profiles for a systems-level understanding of their functions in the uninfected condition and as a response to BmNPV.

Morphology and activities of cell populations of haemocytes in Oncomelania hupensis following Schistosoma japonicum infection

Oncomelania hupensis is the only obligatory intermediate host of Schistosoma japonicum, the pathogen of zoonosis schistosomiasis. Haemocytes play a critical role in the cellular immune defence of O. hupensis against S. japonicum challenge. Here, the morphology and classification of haemocytes of O. hupensis were investigated by Giemsa staining and light microscopy, combining with the scanning and transmission electron microscopy and flow cytometry. Granulocytes and hyalinocytes were confirmed as two main types of haemocytes, account for ~ 10% and ~ 90% of all haemocytes, with size varying in 4.3–10.9 μm and 0.4–30.8 μm, respectively. Subpopulations can be identified further by granule feature, shape, size, and surface and inner structure of cells. The heterogeneity in morphology implied varied developmental process and function of haemocyte subpopulations. After the S. japonicum challenge, haemocytes of O. hupensis respond to S. japonicum invasion immediately. The dynamic change of haemocyte subpopulations indicates that the small hyalinocyte could differentiate into a larger one or granulocyte after S. japonicum challenge, and the granulocytes and larger hyalinocytes play leading roles in early defence reaction, but in different ways. Phagocytosis and apoptosis of haemocytes in O. hupensis were proved to be related to immune defence against S. japonicum, with the combined effect of granulocytes and larger hyalinocytes. However, the main pathway of each subpopulation to take effect in different periods need further investigation.

Quantitative and Qualitative Impacts of Selected Arthropod Venoms on the Larval Haemogram of the Greater Wax Moth, Galleria mellonella (Linnaeus) (Lepidoptera: Pyralidae)

The greater wax moth, Galleria mellonella (Linnaeus) (Lepidoptera: Pyralidae) is the most destructive pest of honey bee, Apis mellifera Linnaeus (Hymenoptera: Apidae), throughout the world. The present study was conducted to determine the quantitative and qualitative impairing effects of the arthropod venoms, viz., death stalker scorpion Leiurus quinquestriatus (Hemprich & Ehrenberg) venom (SV), oriental Hornet (wasp) Vespa orientalis Linnaeus venom (WV) and Apitoxin of A. mellifera (AP) on the larval haemogram. For this purpose, the 3rd instar larvae were treated with LC50 of each of these venoms (3428.9, 2412.6, and 956.16 ppm, respectively). The haematological investigation was conducted in haemolymph of the 5th and 7th (last) instar larvae. The important results could be summarized as follows. Five basic types of the freely circulating haemocytes in the haemolymph of last instar (7th) larvae of G. mellonella had been identified: Prohemocytes (PRs), Plasmatocytes (PLs), Granulocytes (GRs), Spherulocytes (SPs) and Oenocytoids (OEs). All venoms unexceptionally prohibited the larvae to produce normal hemocyte population (count). No certain trend of disturbance in the differential hemocyte counts of circulating hemocytes in larvae of G. mellonella after treatment with the arthropod venoms. Increasing or decreasing population of the circulating hemocytes seemed to depend on the potency of the venom, hemocyte type and the larval instar. In PRs of last instar larvae, some cytopathological features had been observed after treatment with AP or WV, but SV failed to cause cytopathological features. With regard to PLs, some cytopathological features had been observed after treatment with AP while both SV and WV failed to cause cytopathological features in this hemocyte type. No venom exhibited cytopathological effects on GRs, SPs or OEs.

Eicosanoid‐induced calcium signaling mediates cellular immune responses of Tenebrio molitor

AbstractCalcium signaling is associated with actin cytoskeleton rearrangement. It is required for expressing cellular immune responses of insect hemocytes. Eicosanoids mediate immune responses by cytoskeleton rearrangement against various pathogen infections in insects. The objective of this study was to investigate cellular immune responses of a mealworm, Tenebrio molitor L. (Coleoptera: Tenebrionidae). The hypothesis tested was that immune responses would be mediated by calcium signaling associated with eicosanoid mediation. Larvae of T. molitor possessed at least four morphological types of hemocytes, most (almost 75%) of which were granulocytes and plasmatocytes. They all exhibited a hemocyte‐spreading behavior by F‐actin extension. Upon bacterial infection, hemocytes exhibited phagocytosis and formed hemocytic nodules. Intracellular calcium was detected in hemocytes. Its amount increased with increasing incubation time after bacterial infection. Inhibition of calcium influx or release from endoplasmic reticulum using specific inhibitors prevented cellular immune responses. Interestingly, treatment with an eicosanoid biosynthesis inhibitor suppressed calcium signals induced by bacterial challenge. Furthermore, treatment with naproxen, a prostaglandin (PG) synthesis inhibitor, or esculetin, a leukotriene synthesis inhibitor, also inhibited the increase of calcium concentration in hemocytes. Among eicosanoids, PGE2 highly stimulated the increase of calcium signals. These results suggest that cellular immune responses of T. molitor are triggered by calcium signaling, which is up‐regulated by eicosanoids.

Hemocytic sarcoma of the body wall in a California king crab Paralithodes californiensis.

Neoplasia is rarely reported in decapod crustaceans, and sarcoma has not been previously reported in any crab species. A California king crab Paralithodes californiensis with a recent history of autotomy (4 legs lost) and anorexia was found dead. Grossly, the crab had a pigmented ulcer on the right cheliped merus. Necropsy tissue samples were placed in 10% neutral buffered formalin and processed routinely for histology. Both histochemical (i.e. Brown and Brenn Gram, Fite-Faraco acid fast, Fontana-Masson, Giemsa, hematoxylin and eosin, Masson's trichrome, periodic acid-Schiff [PAS], phosphotungstic acid-hematoxylin, and von Kossa) and immunohistochemical (i.e. cytokeratin, vimentin, and lysozyme) stains were performed. The body wall (presumably of the right cheliped merus) was ulcerated and subtended by a densely cellular, unencapsulated, invasive neoplasm composed of spindle cells arranged in intersecting streams and bundles embedded in a small to moderate amount of fibromatous stroma. Neoplastic cells were oval to elongate with fibrillar, pale eosinophilic cytoplasm that occasionally contained moderate numbers of small, spherical, brightly eosinophilic granules that were highlighted with PAS and Giemsa stains. Neoplastic cells had mild atypia and no evident mitoses. Immunohistochemical stains were noncontributory. This neoplasm is consistent with hemocytic sarcoma of semi-granulocytic origin. Decapod crustaceans have 3 types of hemocytes: hyalinocytes, granulocytes, and semi-granulocytes. Neoplastic cells had PAS- and Giemsa-positive granules, which are present in both semi-granulocytes and granulocytes. Semi-granulocytes can elongate and are associated with deposition of extracellular matrix during some immune responses. Neoplastic cells were elongate and associated with deposition of matrix. These findings suggest neoplastic cells were of semi-granulocytic origin.

Immune Cell Production Is Targeted by Parasitoid Wasp Virulence in a Drosophila-Parasitoid Wasp Interaction.

The interactions between Drosophila melanogaster and the parasitoid wasps that infect Drosophila species provide an important model for understanding host–parasite relationships. Following parasitoid infection, D. melanogaster larvae mount a response in which immune cells (hemocytes) form a capsule around the wasp egg, which then melanizes, leading to death of the parasitoid. Previous studies have found that host hemocyte load; the number of hemocytes available for the encapsulation response; and the production of lamellocytes, an infection induced hemocyte type, are major determinants of host resistance. Parasitoids have evolved various virulence mechanisms to overcome the immune response of the D. melanogaster host, including both active immune suppression by venom proteins and passive immune evasive mechanisms. We identified a previously undescribed parasitoid species, Asobara sp. AsDen, which utilizes an active virulence mechanism to infect D. melanogaster hosts. Asobara sp. AsDen infection inhibits host hemocyte expression of msn, a member of the JNK signaling pathway, which plays a role in lamellocyte production. Asobara sp. AsDen infection restricts the production of lamellocytes as assayed by hemocyte cell morphology and altered msn expression. Our findings suggest that Asobara sp. AsDen infection alters host signaling to suppress immunity.

AGE RELATED HEMOCYTE COMPOSITION IN AUTUMN GENERATION OF APIS MELLIFERA L.

AGE RELATED HEMOCYTE COMPOSITION IN AUTUMN GENERATION OF APIS MELLIFERA L.

Functional Characterization of the Pacific Oyster, Crassostrea gigas (Bivalvia: Ostreidae), Hemocytes Under Normoxia and Short-Term Hypoxia

Hemolymph cellular composition, morphology and functional properties of the Pacific oyster (Crassostrea gigas) hemocytes were studied. Three hemocyte types (agranulocytes, hyalinocytes and granulocytes) were described in hemolymph. The morphology of each type was characterized by light microscopy and flow cytometry. Agranular cells (agranulocytes and hyalinocytes) were the dominant type of cells in hemolymph; their number was 86.7±2.7% of total cell count. Under hypoxia the number of agranulocytes increased (37.4% for control group versus 95.3% for hypoxic probes), whereas granulocyte and hyalinocyte number decreased up to 3.9% and 0.7% in hypoxic specimens respectively. The spontaneous ROS production decreased in each hemocyte type after exposure to hypoxia. Low dissolved oxygen did not influence hemocyte proliferation and mortality level.

Identification of haemocytes in the haemolymph of desert locust, Schistocerca gregaria and their activity against Bacillus thuringiensis israelensis

This study aimed to understand the role played by haemocytes of Schistocerca gregaria adults in response to injection with Bacillus thuringiensis israelensis (Bti) into the hemocoel. Light microscopy recognized four types of haemocytes namely: prohaemocytes (PRs), plsamatocytes (PLs), granular cells (GRs) and coagulocytes (COs). Different responses were observed in the haemocyte populations at different time intervals (6, 12 24 and 48 h) following injection with a sublethal dose of bacteria; (1) Pathological consequences in the haemocytes including variation in the cell volume, vacuolization in the cytoplasm, distortion of the cell membrane and pycnosis in the nuclei, (2) Various changes in the differential haemocyte counts (DHCs), the most important is a decrease in the numbers of GRs and COs accompanied with an increase in PLs and PRs, (3) A marked decrease in the total haemocyte counts (THCs) at most time periods. (4) Phagocytosis was shown during all periods post-injection with peak at 6 h, and PLs were the essential phagocytic cell type. (5) A significant increase in nodule counts at all time intervals post-injection was observed above controls, with the peak was at 12 h post-injection.

Effect of Different Host Plants on The Different Haemocyte Counts and Haemocyte Viability of Larvae of Spodoptera littoralis and Agrotis ipsilon

The present study aimed to investigate the effect of different six host plants namely, Cabbage, alfalfa, Jaw’s mallow, lettuce, turnip, and castor leaves on the total haemocyte count (THC), percentage of haemocyte viability, and the percentage of each type of haemocyte (differential haemocyte count, DHC) in Spodoptera littoralis and Agrotis ipsilon fourth instar larvae. There are five types of haemocytes in A. ipsilon and S. littoralis larvae; Prohaemocyte, Plasmatocyte, Granulocyte, Spherocytes, and Oenocyte. Results recorded the highest value 13.3±0.68 of Prohaemocyte at lettuce and the lowest value 9.3 for Cabbage, alfalfa and turnip. On the other hand, Prohaemocyte recorded the highest value 12.6 ± 0.9 in the case of castor feeding and 8.7 ± 0.3 for turnip for S. littoralis. Plasmatocyte recorded 45.3 ± 2.9 cells/mm3for A. ipsilon feed on turnip and 47.3 ± 1.8 cells/mm3for S. littoralis feed on lettuce as the highest value while Granulocyte recorded 33 ± 4.1 and 35 ± 0.7 for A. ipsilon feed on Jaw’s mallow, respectively. Spherocytes recoded 15.3 ± 0.9 and 12.3 ± 0.9 for A. ipsilon and S. littoralis feed on alfalfa. Finally, Oenocyte recorded 7.7 ± 1.5 and 7.3 ± 1.4 for A. ipsilon and S. littoralis feed on castor. Total haemocytic count recorded 29 ± 0.3 and 36 ± 0.75 cells/mm3 as the highest value when both A. ipsilon and S. littoralis feed on Alfalfa. Also, the haemocyte viability % recorded the highest value 91.5 ± 2.6 and 96.2 ± 0.8 % for A. ipsilon and S. littoralis feed on feed on Alfalfa. The result recorded increasing DHC level after feeding of the fourth larval instar of S. littoralis and A. ipsilon on different plant hosts such an increase in DHC gives an impression that blood cells may share in detoxifying. The most obvious activity of haemocyte is phagocytosis. In this context, the most active phagocytes are the Plasmatocyte, Plasmatocyte which was implicated in the encapsulation of necrotic tissues.