Cotesia flavipes (CAM) (Hymenoptera: Braconidae) Supresses Immune Responses In Diatraea flavipennella (BOX) (Lepidoptera: Crambidae)

Abstract

The present research aimed to elucidate which aspects of immune responses in Diatraea flavipennella are suppressed by the parasitoid Cotesia flavipes, thus, ensuring parasitism success. We investigated the presence of apoptosis in fat body cells through the TUNEL technique. According to the results, reduced levels of nitric oxide and phenoloxidase activity were observed in larvae parasitized for three days, and reduced total number of hemocytes, after three and seven days. An increase in plasmatocytes and decrease in spherulocytes numbers were observed in the differential count on the third day of parasitism. The number of melanized microspheres in parasitized larvae was low and indicated less intense melanization. The ultrastructural analysis confirmed the immunosuppressive effect of C. flavipes on the encapsulation response of D. flavipennella because only the formation of hemocytes capsules, adhered to the microspheres' surface, was evidenced in non-parasitized caterpillars. The effect of parasitism was also recorded on the third day with the presence of hemocytes and apoptosis in fat body cells, including aspects of degeneration in the latter. We concluded that C. flavipes suppresses cellular and humoral immunological responses in D. flavipennella and drastically affects the host's fat tissue.

Effect of Prarasitism by Bracon Hebetor Wasp (Hymenoptera-Braconidae) On Cellular Immune Response of Polidia Interpunctella and Ephestia Kuehniella Larvae

“…While in E. kuehniella5 th larval instars, they decreased significantly at 24 and 48 hrs post parasitism and non-significantly at 12 and 72 hrs post parasitism. Our results were in agreement with the finding of Passos et al, (2014) they noticed that a decrease in spherulocytes numbers on the third day of Diatraea flavipennella parasitized by the parasitoid Cotesia flavipes.…”

“…While in E. kuehniella 5 th larval instars, they decreased significantly at 24 and 48 hrs post parasitism and nonsignificantly at 12 and 72 hrs post parasitism. Our results were in consistent with This was in consistent with Passos et al (2014) who noticed a decrease in spherulocytes numbers on the third day of in Diatraea flavipennella parasitized by the parasitoid Cotesia flavipes who noticed a decrease in spherulocytes numbers on the third day of in Diatraea flavipennella parasitized by the parasitoid Cotesia flavipes. The role of SP is poorly known.…”

“…In contrary, some parasitoid and host systems, parasitism leads to a significant reduction of THCs (Yu et al, 2007 andNishikawa et al, 2013), presumably due to either induced immunosuppressant (Stettler et al, 1998) or cell death of the circulating hemocytes and histolysis of the hematopoietic organ (Teramoto and Tanaka, 2004).In addition, the total hemocyte numbers in P. xylostella pupae parasitized by Diadegmasemiclausum declined (Huang et al, 2009). Similar results have been reported for other insects after parasitism with Asobara japonica (Mabiala-Moundoungou et al, 2010 andPassos et al, 2014), Choristoneur afumiferana parasitized by Tranosemarostrale (Doucet and Cusson, 1996) and for older Lacanobiaoleracea larvae injected with the venom of Pimpla hypochondriaca (Richards and Parkinson, 2000).…”

Cotesia flavipes Cameron (Hymenoptera: Braconidae) alters the nutrients in the hemolymph, fat body, and cytochemistry of Diatraea flavipennella Box (Lepidoptera: Crambidae) hemocytes

“…Several other proteins have been identified, including carboxylesterases specific to teratocytes that are involved in the hydrolysis of host lipids (GOPALAPILLAI et al, 2005). We evidenced teratocytes in caterpillars of D. flavipennella parasisted by C. flavipes (PASSOS et al, 2014) The presence of parasitoids causes differential changes in the biochemical profile of the hemolymph and fat body in the C. flavipes-D. flavipennella interaction. Furthermore, this interaction alters the cytochemistry of hemocytes and causes reduction in the reserve tissue, resulting in successful parasitism.…”

“…However, it is known that nutritional and physiological interaction depends on the evolutionary history of that interaction because the parasitoid's host regulation is species-specific (WHITFIELD, 1998;NAKAMATSU et al, 2002). To date, studies on host-parasitoid interactions between C. flavipes and D. flavipennella are rare (PASSOS et al, 2014); since introduced in Brazil, this parasitoid has been produced in the laboratory on D. saccharalis and released in the field to control both borer species. A reversal predominance of the sugarcane borer species occurred in the last 30 years in the state of Alagoas in Brazil (FREITAS et al, 2006) showing D. flavipennella as currently the predominant species in Northeastern Brazil.…”