Environmental Entomology (1983) 12, 397-399

M.A. Mohamed, H.C. Coppel and J.D. Podgwaite (1983)
Artificially-induced nucleopolyhedrosis virus epizootic in populations of Neodiprion sertifer (Hymenoptera: Diprionidae)
Environmental Entomology 12 (2), 397-399
Abstract: An artificially-induced epizootic was created in European pine sawfly (N. sertifer) populations at density levels of 5, 7, and 10 colonies per tree when plots were treated with 3.5 x 10⁸ polyhedral inclusion bodies (PIB) per 0.04 ha. The progress of the epizootic was followed daily. The onset of mortality was at 13 days posttreatment, with a peak mortality period between 14 and 16 days across all density situations. During this period, ca. 70% of the total larval mortality was recorded. Of all the larval instars that died, the 4th experienced the greatest percentage of virus-induced mortality (ca. 58%). The average number of PIB accumulated per larva was inversely related to the density situations. That is, larvae in a low-density situation (five colonies per tree) accumulated more virus than those in a moderate-density situation (seven colonies per tree), and similarly between the moderate- and high-density situations (10 colonies per tree). This resulted in an inverse relationship between the average number of PIB produced per plot and colony density per tree: 2.92 x 10⁹, 9.00 x 10⁸, and 3.3 x 10⁸, in low-, moderate-, and high-density situations, respectively.
(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:
population dynamics/epizootiology
inundative/inoculative release

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Neodiprion sertifer	Pine (Pinus)	U.S.A. (mid N)
Gammabaculovirus nesertiferis (entomopathogen)	Neodiprion sertifer	Pine (Pinus)	U.S.A. (mid N)