BioControl (2005) 50, 761-770

Tiago Martins, Luísa Oliveira and Patrícia Garcia (2005)
Larval mortality factors of Spodoptera littoralis in the Azores
BioControl 50 (5), 761-770
Abstract: Mortality among larval developmental stages of Spodoptera littoralis (Boisduval) (Lepidoptera: Noctuidae), was determined by weekly sampling on weeds in a pasture on São Miguel Island (Azores, Portugal), from August to December, over a 3-year period (1999-2001). In all the years surveyed, larvae of S. littoralis usually appeared in pastures after the third week of August, with higher abundances in September and the beginning of October. Three different factors causing larval mortality were identified: one fungal pathogen, Furia virescens (Thaxter) Humber (Zygomycetes: Entomophthoraceae), two nucleopolyhedroviruses and one larval parasitoid, Meteorus communis (Cresson) (Hymenoptera: Braconidae). The percentages of dead larvae infected by virus or fungus were significantly higher than the other causes of mortality, regardless of the year. Furthermore, the percentage of larvae that died due to virus contamination was generally higher than the percentage of larvae infected by fungus. Significant correlations between the environmental factors and the percentage of larvae infected by virus or by fungus, were only observed during 2001. In 2001, the prevalence of fungal infection was negatively correlated with that of viral infection although prevalences of these two agents were positively correlated in both 1999 and 2000. These results show that virus and fungus are potential biological control agents for S. littoralis in Azores.
(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): Luisa Oliveira

Research topic(s) for pests/diseases/weeds:
population dynamics/ epidemiology
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
population dynamics/epizootiology
surveys/distribution/isolation

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Spodoptera littoralis	Grasses/turf/rangeland	Portugal (Azores)
Meteorus pendulus (parasitoid)	Spodoptera littoralis	Grasses/turf/rangeland	Portugal (Azores)
Furia virescens (entomopathogen)	Spodoptera littoralis	Grasses/turf/rangeland	Portugal (Azores)