01346nas a2200145 4500008004100000245012400041210006900165300000800234490000700242520083400249653001201083100002001095700001901115856006601134 1981 eng d00aInstar Susceptibility of Simulium vittatum (Diptera: Simuliidae) to the Entomogenous Nematode, Neoaplectana carpocapsae0 aInstar Susceptibility of Simulium vittatum Diptera Simuliidae to a1-50 v133 a

Laboratory bioassays showed that the susceptibility of Simulium vittatum to Neoaplectana carpocapsae increased with successive larval instars. First, second, and third instar larvae were resistant to infection, while seventh instars were highly susceptible. Significant differences in intra-instar susceptibility were also evident, as mortality ranged from 58% for the smallest seventh instar larvae to 97% for the largest. Dissections revealed that the basis for the resistance of early instars was physical exclusion of the comparatively large nematodes. The principle factor regulating the susceptibility of mid and late instars was injury to nematodes caused by larval mouthparts during ingestion. Differences in intra-instar susceptibility were similarly related to nematode injury.

10abiology1 aGaugler, R., R.1 aMolloy, D., P. uhttp://www.ncbi.nlm.nih.gov/pmc/articles/PMC2618041/pdf/1.pdf