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.pdf01506nas a2200169 4500008004100000245012500041210006900166300001400235490000800249520088800257653001201145100002001157700001901177700001601196700001401212856011001226 1980 eng d00aA Bioassay System for the Evaluation of Black Fly (Diptera: Simuliidae) Control Agents Under Simulated Stream Conditions0 aBioassay System for the Evaluation of Black Fly Diptera Simuliid a1271-12760 v1123 a

A new bioassay unit is described which provides simulated stream conditions for testing control agents against black fly larvae. Attributes include uniform flow, high control survival, and excellent visibility for observing larval behavior. It also possesses the unique advantage of using recycled water, continuously supplied fresh water, or both simultaneously. The unit has performed satisfactorily in assays against black flies using pathogens, parasites, and chemicals. In addition, stream invertebrates from four insect orders have been maintained in the unit.

A simple and inexpensive incubation unit is also described which possesses several of the advantages of the bioassay unit. It lacks the capability for recirculation and is generally less versatile than the bioassay unit; however, it is useful for the maintenance and observation of stream insects.

10abiology1 aGaugler, R., R.1 aMolloy, D., P.1 aHaskins, T.1 aRider, G. uhttp://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=8538374&fileId=S0008347X0001660601462nas a2200145 4500008004100000245014500041210006900186300001200255490000600267520095300273653001201226100002001238700001901258856003901277 1980 eng d00aFeeding Inhibition in Black Fly Larvae (Diptera: Simuliidae) and Its Effects on the Pathogenicity of Bacillus thuringiensis var. israelensis0 aFeeding Inhibition in Black Fly Larvae Diptera Simuliidae and It a704-7080 v93 a

The normal feeding behavior of Simulium vittatum larvae was disrupted following exposure to high concentrations of suspended particles under simulated stream conditions. Virtually all particulates tested caused inhibition of feeding at a concentration of 50 mg/liter, indicating that inhibition is a nonspecific response. The percentage of larvae with inhibited feeding increased with increasing particle concentration. Our results indicate that inhibition was a consequence of rapid gut filling.

The pathogenicity of Bacillus thuringiensis var. israelensis against S. vittatum was diminished or enhanced depending on whether feeding inhibition was induced before or after bacterial exposure. These results were attributed to reduced rates of bacterial ingestion and voidance, respectively. Such effects may have important implications in laboratory bioassays and field control.

10abiology1 aGaugler, R., R.1 aMolloy, D., P. uhttps://doi.org/10.1093/ee/9.5.704