Submitted to: Environmental Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 22, 2007
Publication Date: August 9, 2007
Citation: Esquivel, J.F., Mowery, S.V. 2007. Host plants of the tarnished plant bug (Heteroptera: Miridae) in Central Texas. Environmental Entomology. 36:725-730. Interpretive Summary: Lygus bug species have become a major pest in cotton production areas following boll weevil eradication. Weeds and row crops were sampled in the Southern Blacklands region of Central Texas, which is in advanced stages of boll weevil eradication, to determine the presence of lygus species and to identify seasonal use of host plants. The tarnished plant bug was the only lygus species found in the region. Thirteen previously unreported host plants were identified for the tarnished plant bug in the region. Seasonal weed hosts that supported high numbers of tarnished plant bugs included: early-season - turnipweed and Mexican hat; mid-season – horseweed; late-season - giant ragweed; and overwintering period - London rocket and henbit. Alfalfa was the main cultivated crop supporting tarnished plant bugs. Cotton yielded very few tarnished plant bugs and none were found in soybeans. The presence of tarnished plant bugs on various seasonal hosts suggests these insects may become a pest of cotton in Central Texas following eradication efforts. Our results provide a detailed assessment of the seasonal hosts supporting tarnished plant bug populations in Central Texas, and should prove useful to producers, Boll Weevil Eradication personnel, and research scientists by providing a baseline for examining post-eradication pest species and abundance.
Technical Abstract: The tarnished plant bug, Lygus lineolaris, has taken on added importance as a pest of cotton in the Cotton Belt following successful eradication efforts for the boll weevil. Because the Southern Blacklands region of Central Texas is in advanced stages of boll weevil eradication, blooming weeds and selected row crops were sampled during a 3-yr study to determine lygus species composition and associated temporal host plants. Lygus lineolaris was the sole lygus species in the region. Additionally, thirteen previously unreported host plants were identified for L. lineolaris in the region. Rapistrum rugosum and Ratibida columnifera were primary weed hosts during the early-season (17 March – 31 May). Conyza canadensis and Ambrosia trifida were primary weed hosts during the mid-season (1 June – 14 August) and late-season (15 August – 30 November), respectively. Sysimbrium irio and Lamium amplexicaule sustained L. lineolaris populations during the overwintering period (1 December – 16 March). Sex ratio and nymphal population data suggest R. rugosum, C. canadensis, A. trifida, and S. irio were key weed hosts supporting reproductive adults during the early-, mid-, late-season, and overwintering period, respectively. Medicago sativa was the leading crop host for L. lineolaris; Glycine max did not yield L. lineolaris. Few L. lineolaris were collected in cotton; however, with reduced insecticide treatments in eradication efforts and the implementation of more species-specific insecticides, L. lineolaris may become a pest of cotton in the region. These results provide a more comprehensive assessment of host plants contributing to L. lineolaris populations in Central Texas.