Dispersal of Lygus lineolaris (Heteroptera: Miridae) Adults Through Cotton Following Nursery Host Destruction

Abstract

Movement of Lygus lineolaris (Palisot de Beauvois) adults following destruction of a nursery plot placed within a cotton ( Gossypium hirsutum L.) field was traced in two field studies. An internal physiological marker was acquired during feeding on the nursery plot and resulted in higher numbers of marked individuals than use of fluorescent dust applied to captured insects. This was in spite of repeated efforts to establish a population of fluorescent-marked individuals. Dispersal immediately following destruction of the nursery plot was adequately modeled as a diffusion process, but emigration from the cotton ocurred within days. When Erigeron annuus (L.) Persoon refuges were nearby, there was a large increase in the number of marked adults found in the refuges one and two days after the nursery host was destroyed. Screenhouse studies showed that the presence of E. annuus near cotton significantly decreased the proportion of adults that remained on the cotton. Projections of colonization potentials were higher for founder populations on E. annuus than on cotton. This suggests that movement toward E. annuus represents efficient use of habitat by this polyphagous species even when E. annuus exists as small patchy refuges within cotton monocultures. Damage to cotton reflected the high L. lineolaris density imposed by the placement and later destruction of the nursery plot, suggesting that damage can result from improper management of nursery hosts.