Applied and Environmental Microbiology (2011) 77, 2954-2960

Oihana Cabodevilla, Eduardo Villar, Cristina Virto, Rosa Murillo, Trevor Williams and Primitivo Caballero (2011)
Intra- and intergenerational persistence of an insect nucleopolyhedrovirus: Adverse effects of sublethal disease on host development, reproduction, and susceptibility to superinfection
Applied and Environmental Microbiology 77 (9), 2954-2960
Abstract: Sublethal infections by Spodoptera exigua multiple nucleopolyhedrovirus (SeMNPV) are common in field populations of the beet armyworm (S. exigua, Hübner) in the Almerian horticultural region of Spain. Inoculation of second, third, and fourth instars with occlusion bodies (OBs) of an isolate (VT-SeAl1) associated with vertically transmitted infections resulted in 15 to 100% of sublethal infection in adult survivors, as determined by reverse transcription-PCR (RT-PCR) detection of viral DNA polymerase transcripts, and quantitative PCR (qPCR) targeted at the DNA polymerase gene. The prevalence of adult sublethal infection was positively related to the inoculum OB concentration consumed during the larval stage. Sublethal infections persisted in OB-treated insects for at least five generations. Viral transcripts were more frequently detected in adult insects than in third instars. qPCR analysis indicated a consistently higher prevalence of sublethal infection than RT-PCR. Sublethal infection was associated with significant reductions in pupal weight, adult emergence, fecundity, and fertility (egg hatch) and significant increases in larval development time and duration of the preoviposition period. Insects taken from a persistently infected experimental population were significantly more susceptible to the OB inoculum than control insects that originated from the same virus-free colony as the persistently infected insects. We conclude that OB treatment results in rapid establishment of sublethal infections that persist between generations and which incur costs in the development and reproductive capacity of the host insect.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Primitivo Caballero, Trevor Williams

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
general biology - morphology - evolution
transmission/dispersal

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Spodoptera exigua		Spain (continental)
Alphabaculovirus spexiguae (entomopathogen)	Spodoptera exigua		Spain (continental)