Stage-specific effects of population density on the development and fertility of the western tarnished plant bug, Lygus hesperus

Colin S. Brent

USDA Arid Land Agricultural Research Center, 21881 N. Cardon Lane, Maricopa, AZ 85238, USA

Abstract

The western tarnished plant bug Lygus hesperus Knight (Heteroptera: Miridae), a major pest of cotton and other key economic crops, was tested for its sensitivity to population density during nymph and adult stages. Nymphs reared to adulthood under increasing densities in laboratory conditions exhibited incremental delays in maturation, heightened mortality rates, and reductions in body mass and various size parameters. In contrast, gonadal activity in both males and females rose with initial density increases. Supplemental nutrients provided to the nymphs failed to offset the negative effects of high density, suggesting that contact frequency, rather than resource partitioning, may be the primary stress. Unlike nymphs, newly eclosed adults exposed to increasing population densities did not suffer negative physiological effects; body mass, mortality rates and patterns of ovipositional activity were unchanged. Collectively, these results indicate that population density can dramatically influence Lygus development, but the specific effects are stage-dependent.

Keywords: environmental stress, fecundity, fluctuating asymmetry, Miridae, mortality rate
Abbreviations: DD, double diet

Correspondence: colin.brent@ars.usda.gov

Received: 19 September 2008 | Accepted: 14 November 2008 | Published: 17 May 2010

ISSN: 1536-2442 | Volume 10, Number 49

Brent CS. 2010. Stage-specific effects of population density on the development and fertility of the western tarnished plant bug, Lygus hesperus. Journal of Insect Science 10:49, available online: insectscience.org/10.49


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