Production of Culex pipiens (Dip.: Culicidae) adults infected by the parasitic nematode Strelkovimermis spiculatus (Nematoda: Mermithidae) for autodissemination control approach
عنوان دوره: دومین کنگره بین المللی حشره شناسی ایران
نویسندگان
چکیده
Inoculative release of the mosquito parasitic nematode, Strelkovimermis spiculatus, showed promising results for Integrated Vector Management (IVM) due to its narrow host range and culture method. The pre-parasitic nematodes penetrate lower instar host in nature and emerge from and kill the host before its pupal stage. Occasionally, the parasites infect later instar host and stay through host adult stage, which can help the parasites disperse to different ponds. To understand this important biological aspect, we have optimized the conditions in the lab to produce the maximum number of nematodes that emerges from adult host. To determine the optimal larval instar and parasite: host ratio, late third, early fourth and late fourth instar larvae, and 5:1, 10:1, 20:1, 40:1 ratios were compared and the percentage of infected adult mosquitoes obtained recorded. Average nematode development time was measured. The sex ratio, number and length of post-parasites emerged from adult hosts were also calculated and compared. The maximum proportion (17.39%) of post-parasites emerged from adults was obtained by the combination of parasite:host ratio of 10:1 and host instar of late 4th. The average duration between infection and nematode emergence was 7.37±0.51 days. The proportion of females to total emerged nematodes from adults was 40%, which is an acceptable ratio for nematodes’ colonization in new water bodies. There was no statistical difference between the length of nematodes emerged from mosquito adults and larvae (P=0.14). This information provided the baseline data and method for further investigation of the parasite dispersal and host manipulation behavior.
کلیدواژه ها
Insect parasitic nematodes؛ Culex pipiens؛ Control؛ autodissemination approach؛ Strelkovimermis spiculatus