Environmental Entomology (1989) 18, 150-156

T.J. Kring, W.C. Yearian and V.B. Steward (1989)
Within-field and within-panicle distribution of Heliothis zea (Lepidoptera: Noctuidae) and Celama sorghiella (Lepidoptera: Noctuidae) eggs in grain sorghum
Environmental Entomology 18 (1), 150-156
Abstract: The within-field and within-panicle distributions of Heliothis zea (Boddie) and Celama sorghiella (Riley) eggs were studied in Arkansas grain sorghum during 1985 and 1986. The distribution of eggs parasitized by Trichogramma spp. was also evaluated. None of the three insect species showed a consistent preference for any portion of a grain sorghum panicle based on either location (upper, middle, or lower third) or flowering stage (1/3, 2/3, or full bloom). H. zea exhibited a clumped within-field spatial pattern for total and parasitized eggs as based on Taylor's indices of aggregation (a = 1.24, b = 1.31, and a = 1.85, b = 1.18, respectively). Total and parasitized C. sorghiella eggs were decidedly more aggregated than those of H. zea with Taylor's indices of a = 2.56, b = 1.46, and a = 3.28, b = 1.34, respectively. Required sample sizes needed to estimate population densities of both species are provided.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Database assignments for author(s): Timothy J. Kring

Research topic(s) for pests/diseases/weeds:
surveys/sampling/distribution

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Helicoverpa zea	Sorghum (crop)	U.S.A. (mid S)
	Nola sorghiella	Sorghum (crop)	U.S.A. (mid S)