Archives of Phytopathology and Plant Protection (1999) 32, 337-350

W.E. Khafagi and E.M. Hegazi (1999)
Latent effects of precocenes (I and II) and juvenile hormone I on Spodoptera littoralis (Boisd.) larvae
Archives of Phytopathology and Plant Protection 32 (4), 337-350
Abstract: The latent effects of precocenes I and II (PI and PH) and juvenile hormone I (JHI) when topically applied to the last three instars of Spodoptera littoralis (Boisd.) larvae have been studied. Application of both PI or PII resulted in morphogenetic abnormalities resemble some effects induced by administration of JHI, e.g., larval-pupal intermediate, partial or severe cases of untanned pupae and imperfect moths. In PII-treatments, the effect was instar-dose-dependent. The intermediate dose (55 μg) was more effective on S. littoralis larvae than other doses. The effectiveness of both doses of 40 or 70 μg in production of deformed larvae and pupae decreased when applied as repeated doses instead of single ones. In Pi-treatments, the lower dose (25 μg) was more harmful to Spodoptera larvae than the higher dose (70 μg). Repeated application by either lower or higher doses did not enhance the production of imperfect insects. Application of JHI induced symptoms ranging from supernumerary instars, larval-pupal intermediate, untanned pupae and deformed adults. The effect was dose-dependent. In all tested compounds, there apparently was a latent or delayed effects. Although the insects were treated while they were larvae the complete effects were not apparent until after the insect had become a pupa or an adult. More efforts will be needed to understand how does precocene interferes with the process of tanning or sclerotization?
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Link to article at publishers website
Database assignments for author(s): Esmat M. Hegazi

Research topic(s) for pests/diseases/weeds:
control - general

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Spodoptera littoralis