Environmental Entomology (1990) 19, 648-655

Alan L. Knight, Larry A. Hull and Edwin G. Rajotte (1990)
Patterns of egg mass deposition of Platynota idaeusalis (Lepidoptera: Tortricidae) within an apple orchard
Environmental Entomology 19 (3), 648-655
Abstract: Two field releases of rubidium (Rb)-labeled, laboratory-reared adult Platynota idaeusalis (Walker) were conducted to measure female adult dispersal and egg mass deposition patterns within a 33-ha (about 7,450 trees) apple orchard in Adams County, Pa. In both studies >3,200 virgin male and female adults (male : female ratio = 1.1:1.0) were reared from rubidium-incorporated diet (3 g Rb/liter) and released on four center trees. Trees were randomly sampled for hatched and unhatched egg masses up to 500 m from the release sites. Atomic absorption spectrophotometry was used to detect rubidium in egg masses, and masses were considered marked if concentrations were >10 ppb. Following the first release, 417 trees were sampled and 39% of the 222 egg masses collected were marked. Following the second release, 260 trees were sampled and 67% of the 346 egg masses collected were marked. The distribution of rubidium-labeled egg, masses demonstrated that spatial patterns of egg mass deposition are primarily local and are affected by ambient air temperatures. For example, 90% of all recovered rubidium-labeled egg masses were found within 65 and 45 m of the release sites, and the most distant labeled egg mass was found at 250 and 170 m, respectively, following adult releases during a warm period in July (daily minimum temperatures, > 16°C) and a cooler period in September (daily minimum temperatures, < 12°C).
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Database assignments for author(s): Alan L. Knight

Research topic(s) for pests/diseases/weeds:
general biology - morphology - evolution
population dynamics/ epidemiology

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Platynota idaeusalis	Apple (Malus)	U.S.A. (NE)