Journal of Entomological Science (1996) 31, 52-62

F.F.R. Nyouki, J.R. Fuxa and A.R. Richter (1996)
Spore-toxin interactions and sublethal effects of Bacillus thuringiensis in Spodoptera frugiperda and Pseudoplusia includens (Lepidoptera Noctuidae)
Journal of Entomological Science 31 (1), 52-62
Abstract: Interactions between the spores and delta-endotoxins of Bacillus thuringiensis Berliner were tested in a low-susceptibility insect, Spodoptera frugiperda (J. E. Smith). The spores (formulation MYD^TM) and one delta-endotoxin (formulation MVP^TM) had additive effects on mortality at a MVP^TM dose of 117,500 µg/g of diet (P < 0.01) and synergistic effects at a MVP^TM dose of 235,000 µg/g diet (P < 0.01). The spores and another delta-endotoxin (formulation MYX^TM) were antagonistic at a MYX^TM dose of 117,500 µg/g diet (P < 0.01) and additive at a MYX^TM dose of 235,000 µg/g diet (P < 0.01). The two delat-endotoxin formulations were additive with one another (P < 0.01). Sublethal concentrations of MVP^TM fed to larvae retarded the development of larvae and pupae for 5 d (P < 0.01) and 1.2 d (P < 0.01), respectively; and decreased pupal weight by 48 mg (P <. 0.01). The spore formulation did not affect (P > 0.05) pupal weight or the life span of larvae or pupae. Median lethal concentrations of MVP^TM and MYX^TM were 6,904 and 7,561 X greater, respectively, in S. frugiperda than in Pseudoplusia includens (Walker). In P. includens, sublethal concentrations of MVP^TM, MYX^TM, and Dipel^TM fed to larvae significantly (P < 0.05) reduced pupal weight and increased pupal life span compared to control insects. MVP^TM and Dipel^TM increased larval life span significantly (P < 0.05), but MYD^TM did not.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
evaluation - screening - selection

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Chrysodeixis includens
	Spodoptera frugiperda