Showing 3 results for Hemocyte
Volume 0, Issue 0 (1-2024)
Abstract
Various factors, such as temperature stress, dietary changes, and the entry of contaminants and infections into the hemolymph, are known to affect insect immune responses by altering hemocyte profiles. The research focused on the hemocyte profile, hemogram across all biological stages, and the morphological and frequency changes of hemocytes in third instar larvae exposed to temperature stress. Cucumber fruits infected with insect larvae were collected and brought to the laboratory, where third instar larvae were extracted from the fruit tissue. The hemolymph was then collected, and after staining with Giemsa solution, hemocytes were identified under a light microscope. The hemogram analysis included measurements of DHC, THC, blood volume, and AHC across all biological stages. In third instar larvae, plasmatocytes and granulocytes were the most abundant, comprising about 56% of the hemocyte population. In contrast, prohemocytes were most frequent in the first instar larvae, accounting for approximately 37%. THC was highest in third instar larvae, indicating a direct correlation between hemolymph volume and total hemocyte count. Temperature stress had a significant impact on hemocyte numbers. Heat stress, with temperatures up to 30 and 35 °C, led to a notable increase in total cell count, granulocytes, and plasmatocytes. Conversely, cold temperatures resulted in a decrease in prohemocytes, plasmatocytes, granulocytes, and the total cell count compared to the control group. Additionally, temperature stress induced hemocyte deformation, with plasmatocytes and granulocytes showing the most pronounced changes under heat stress, including torn cell walls and loss of cell contents at 35 ○C.
Volume 3, Issue 4 (12-2014)
Abstract
The Mediterranean flour moth, Ephestia kuehniella Zeller, is one of the major pests in stored products worldwide. Several problems assossiated with the use of conventional insecticides have strongly demonstrated the need for applying alternative safe compounds such as insect growth regulators (IGRs). In the present study, growth regulating activity and hematological effects of pyriproxifen and methoxyfenozide were evaluated on E. kuehniella larvae. Effects of the insecticides were evaluated under laboratory conditions set at 26 ± 1 °C and 75% RH. Findings indicated that inhibition dose for fifty percent of population (ID50) was equal to 0.16 µg/mg larvae for pyriproxifen and 0.4 µg/mg larvae for methoxyfenozide, showing the considerable growth regulating effect on two-day-old fifth instar larvae. Then, influence of estimated doses were investigated on the insect hemocytes including total hemocyte count (THC) and differential hemocyte count (DHC). THC and the proportion of plasmatocytes were decreased as pyriproxifen doses increased, while, the granulocytes level was increased. In contrast, application of sublethal doses of methoxyfenozide caused a conciderable increase in THC and the plasmatocytes density, while, number of granulocytes was decreased. Since the total number of hemocytes and the proportion of plasmatocytes are very crucial in immune responses of insects, pyriproxifen could be used as an immunosuppressive pesticide in integrated control of E. kuehniella.
Yalda Baniesmaeili, Arash Akbazradeh, Gholam Hossein Riazi, Farzin Abdollahi, Mohammad Niroomand,
Volume 11, Issue 4 (12-2022)
Abstract
In this study, the effects of powder and leaf extract of Moringa oleifera on hemolymph factors of Litopenaeus vannamei in response to salinity stress were evaluated. After 8 weeks of feeding with powder (25, 50 and 100g / kg) and extract (0.25, 0.5 and 0.1 g/kg) leaves of Moringa and control treatment without Moringa, all treatments were exposed to short-term salinity stress (5 and 55 ppt). There was a statistically significant difference in total and differential count of homocytes in different dietary treatments in all three normal conditions and under salinity stress of 5 and 55 pp (p<0.05). Under normal conditions and high salinity, shrimps fed with Moringa leaf extract showed higher number of homocytes than other treatments. In stress-free conditions, the number of semi-granular cells in powder and extract treatments was higher than the control group. At 5 ppt, Moringa powder treatments had higher semi-granular and at 55 ppt salinity, the leaf powder group (100 g/kg) and the leaf extract (0.25 g/kg) showed the highest values, respectively. Overall, the results of this study showed the positive effects of using Moringa leaf powder and extract on innate immune system function and exposure to salinity stress in shrimp