TY - JOUR

T1 - Microsporidia-cypovirus interactions during simultaneous infection of the tree defoliator Dendrolimus sibiricus (Lepidoptera: Lasiocampidae)

AU - Rumiantseva, Arina S.

AU - Ageev, Aleksander A.

AU - Ignatieva, Anastasia N.

AU - Yakimova, Maria E.

AU - Kharlamova, Daria D.

AU - Martemyanov, Vyacheslav V.

AU - Tokarev, Yuri S.

N1 - The authors are indebted to Bakhtiar Mirzakhodzhaev (Uzbek Research Institute of Sericulture, Tashkent, Uzbekistan) for kind gift of N. bombycis spores and to Vadim Kryukov (Institute of Systematics and Ecology of Animals, Novosibirsk, Russia) for consultation on statistics. The authors are grateful to Anna Felgenhauer, Master of Arts in Applied Linguistics (Wisconsin, USA) for checking grammar and style of the manuscript. Supported by RSF, grant # 23-16-46009 (field collection and laboratory cultivation of insects, in vivo propagation of entomopathogens, experimental design, data analysis) and grant # 23-66-10015 (bioassays with larch population of D. sibiricus).

PY - 2024/11

Y1 - 2024/11

N2 - The Siberian moth, Dendrolimus sibiricus is a dangerous forest defoliator, the number one pest of boreal forests in Asia. Search for effective and ecologically friendly control measures drives attention to microbial pathogens. Viruses and microsporidia are obligate intracellular parasites widespread in insect populations causing either chronic or acute infections. Interactions of these pathogens vary from antagonistic to synergistic. The goal of the work was to test a recently discovered cytoplasmatic polyhedrosis virus (cypovirus) strain DsCPV-1 isolated from D.sibiricus, combined with a microsporidium, against D. sibiricus, by feeding the inoculum (viral polyhedral and microsporidian spores). Three different microsporidian parasites of lepidopterans were tested against D. sibiricus as monoinfection: Nosema bombycis from silkworm, N. pyrausta from corn borer, and Tubulinosema loxostegi from beet webworm. Nosema bombycis was the most virulent, with a median lethal time of 7 days in the first and second instars treated with 100,000 and 1 million spores/larva, respectively. Nosema bombycis (dose 100,000 spores/larva) was chosen to test it as mixed infection in combination with an extremely low dose of DsCPV-1 (1 polyhedron/larva) against two races of D. sibiricus second instar larvae (the fir-feeding race and the larch-feeding race). The mixed infection demonstrated the most prominent negative effect on larval lethal time and weight for the both tested races. Mixed infections showed a synergistic effect for the fir-feeding larvae but additive effect only for the larch feeding larvae. Both pathogens co-developed successfully in the larvae with equal ratio of producing inoculum. The combination of these entomopathogens is therefore promising for forest protection against the Siberian moth and could be the way to significantly decrease the amount of pathogens applied in field.

AB - The Siberian moth, Dendrolimus sibiricus is a dangerous forest defoliator, the number one pest of boreal forests in Asia. Search for effective and ecologically friendly control measures drives attention to microbial pathogens. Viruses and microsporidia are obligate intracellular parasites widespread in insect populations causing either chronic or acute infections. Interactions of these pathogens vary from antagonistic to synergistic. The goal of the work was to test a recently discovered cytoplasmatic polyhedrosis virus (cypovirus) strain DsCPV-1 isolated from D.sibiricus, combined with a microsporidium, against D. sibiricus, by feeding the inoculum (viral polyhedral and microsporidian spores). Three different microsporidian parasites of lepidopterans were tested against D. sibiricus as monoinfection: Nosema bombycis from silkworm, N. pyrausta from corn borer, and Tubulinosema loxostegi from beet webworm. Nosema bombycis was the most virulent, with a median lethal time of 7 days in the first and second instars treated with 100,000 and 1 million spores/larva, respectively. Nosema bombycis (dose 100,000 spores/larva) was chosen to test it as mixed infection in combination with an extremely low dose of DsCPV-1 (1 polyhedron/larva) against two races of D. sibiricus second instar larvae (the fir-feeding race and the larch-feeding race). The mixed infection demonstrated the most prominent negative effect on larval lethal time and weight for the both tested races. Mixed infections showed a synergistic effect for the fir-feeding larvae but additive effect only for the larch feeding larvae. Both pathogens co-developed successfully in the larvae with equal ratio of producing inoculum. The combination of these entomopathogens is therefore promising for forest protection against the Siberian moth and could be the way to significantly decrease the amount of pathogens applied in field.

KW - Cytoplasmic polyhedrosis virus

KW - Microbial control

KW - Microsporidia

KW - Mixed infection

KW - Siberian moth

KW - Susceptibility

UR - https://www.scopus.com/record/display.uri?eid=2-s2.0-85203797052&origin=inward&txGid=9496b046018fc6099c7cb591fe7572a1

UR - https://www.mendeley.com/catalogue/c65dab3a-929a-3957-bf2f-8e4fe35cc10f/

U2 - 10.1016/j.jip.2024.108199

DO - 10.1016/j.jip.2024.108199

M3 - Article

C2 - 39277164

VL - 207

JO - Journal of Invertebrate Pathology

JF - Journal of Invertebrate Pathology

SN - 0022-2011

M1 - 108199

ER -