An epizootic of patent iridescent virus disease in multiple species ofblackflies in Chiapas, Mexico

摘要

Simulium blackfly larvae (Diptera: Simuliidae) were collected from rivers and streams at 500-1500 m a.s.l. in Chiapas State of southern Mexico. Among 45 sites surveyed over an area of 2300 km(2) (around 15 degrees 15' N 92 degrees 20' W), some Simulium larvae from three sites were opalescent violet-blue, interpreted as patent infection with invertebrate iridescent virus (IIV). Dissection confirmed the presence of putative Iridovirus particles, 130 nm diameter, but no IIV isolates were obtained from homogenates injected into Galleria mellonella (L) larvae (Lepidoptera: Pyralidae). All Simulium with patent IIV infection died before metamorphosis, whereas similar to 60% of asymptomatic Simulium survived to adulthood in the laboratory.