Light microscopy of microsporidian spores and baculovirus occlusion bodies in Epinotia aporema and Helicoverpa gelotopoeon larval tissues, respectively

Abstract

Entomopathogens help regulate natural insect populations, and their use in pest management is the subject of active research. Classical and molecular techniques are currently available to elucidate disease etiology and pathogenesis. Here, we performed an Azan trichrome stain for light microscopic visualization of pathogens in the larval tissues of two Neotropical lepidopterans.

Epinotia aporema larvae exhibiting symptoms of microsporidiosis were fortuitously detected in a rearing facility (IMyZA-INTA, Argentina), while Helicoverpa gelotopoeon specimens were experimentally infected with an Argentinean isolate of Helicoverpa armigera nucleopolyhedrovirus (HearNPV). Caterpillars were fixed in Duboscq-Brasil and paraffin embedded. Microtome sections (5 μm-thick) were deparaffinized and stained2 for observation under a Nikon Eclipse 80i microscope equipped with a Nikon DS-U3 digital camera.