Entomologia Experimentalis et Applicata (2005) 116, 191-197

Marc Sporleder, Jürgen Kroschel, Jürg Huber and Aziz Lagnaoui (2005)
An improved method to determine the biological activity (LC₅₀) of the granulovirus PoGV in its host Phthorimaea operculella
Entomologia Experimentalis et Applicata 116 (3), 191-197
Abstract: Granulovirus (PoGV) is a promising candidate to substitute for chemical insecticides in integrated pest management (IPM) of the potato tuber moth, Phthorimaea operculella (Zeller) (Lepidoptera: Gelechiidae). A procedure to assess pathogenicity (LC₅₀) and its standardization is crucial for research into the use of pathogens as biocontrol agents. In the present study, an egg-dip bioassay method was developed and its precision tested in a series of six bioassays over a time period of 18 months. Bioassays were carried out at 25 °C incubation temperature. The probit model as a statistical analysis method for the interpretation of concentration responses proved better than the exponential model. LC₅₀ values ranged from 2.3 x 10⁶ to 10⁷ granules ml^-1 with a mean of 5 x 10⁶ granules ml^-1 and regression slopes varied between 0.73 and 1.05 with a mean of 0.84. LC₅₀ values and slopes displayed no significant differences according to their 95% confidence limits. The rate of harvested infected larvae showed a linear increase with increasing concentration on a log-log scale. The mean natural mortality was 15% (SE ± 1.8%) and can be considered as a main factor producing variability among bioassays. The advantages of this bioassay method and its application in PoGV research are discussed.
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Link to article at publishers website
Database assignments for author(s): Marc Sporleder, Jürgen Kroschel, Jürg Huber, Aziz Lagnaoui

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

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Phthorimaea operculella
Betabaculovirus phoperculellae (entomopathogen)	Phthorimaea operculella