Malysh S.M. 2026. Infectivity of two microsporidia (Holomycota: Rozellomycota) from the cotton bollworm and the silkworm to the garden tiger moth, Arctia caja (Linnaeus, 1758) (Lepidoptera: Erebidae) // Euroasian Entomological Journal. Vol.25. No.2: 106–114 [in English].
All-Russian Institute of Plant Protection (VIZR), Podbelskogo 3, Saint Petersburg, Pushkin 196608 Russia. E-mail: s.malysh-vizr@yandex.ru
doi 10.15298/euroasentj.25.02.07
ABSTRACT. Microsporidia are obligate intracellular parasitic protists related to fungi. For lepidopteran insects, this group of pathogens acts as natural population regulators and is considered as promising resources of biological products. In this work, two closely related isolates of microsporidia were studied: Nosema bombycis (Naegeli, 1857) from the silkworm Bombyx mori (Linnaeus, 1758) (Bombycoidea: Bombycidae) and Nosema sp. from the cotton bollworm Helicoverpa armigera (Hübner, 1808) (Noctuoidea: Noctuidae). Their ability to cause infection in larvae of the garden tiger moth, Arctia caja (Linnaeus, 1758) (Noctuoidea: Erebidae), a polyphagous agricultural pest, was tested. Significant differences were observed between the two microsporidia in terms of virulence and ability to accumulate spores in this host. It was also found that the isolate from the cotton bollworm is able to maintain its infective properties for more than a year.
KEY WORDS: Laboratory cultivation, Lepidoptera, insect pathogen, mass production, parasitic protists, host range, virulence, biological control.