Journal of Insect Science (2008) 8 (49), p. 12 (Goodell)

B. Peter Goodell (2008)
Measuring localized movement of Lygus into cotton
Journal of Insect Science 8 (49), 12-12
in P.B. Goodell and P.C. Ellsworth, organizers: Second International Lygus Symposium, Pacific Grove, California, April 15-19 2007
Abstract: Lygus hesperus populations develop both external and internal to the San Joaquin Valley in California. In certain years, weed hosts are favored by precipitation patterns and these can provide extended habitat on which Lygus populations can build. In 2005, tarweed, Hemizonia kelloggii, was found in high density bordering cotton fields on uncultivated rangeland. Lygus populations were sampled weekly from tarweed on uncultivated rangeland and in the adjoining cotton. Both Pima and Acala upland cottons were sampled. In addition to tarweed, almonds (bearing and non-bearing), pistachios, onions and highway frontage were bordering these cotton fields, but were not sampled. Lygus population development continued into July on tarweed before soil moisture was depleted and the majority of the tarweed population senesced. Lygus population densities did not increase in the cotton most proximal to tarweed until the majority of tarweed in the area had senesced. Based on proximal sampling, other crops that bordered the study area acted as substantial sources for Lygus adults during earlier periods of time. These data suggest that Lygus remain on hosts as long as possible before finally moving due to unsuitable habitat or habitat destruction caused by production practices. In addition, internal sources (bordering crops) were as significant in providing Lygus as was the uncultivated rangeland. This suggests that internal sources of Lygus can be as important as external sources and could be more important on an annual basis as opposed to occasional outbreaks from external sources.
Database assignments for author(s): Peter B. Goodell

Research topic(s) for pests/diseases/weeds:
population dynamics/ epidemiology
environment - cropping system/rotation

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Lygus hesperus		U.S.A. (SW)