|FLEMING, DANIEL - Mississippi State University|
|MUSSER, FRED - Mississippi State University|
Submitted to: Environmental Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/11/2015
Publication Date: 6/1/2015
Publication URL: http://handle.nal.usda.gov/10113/61396
Citation: Fleming, D.E., Roehrdanz, R.L., Allen, K.C., Musser, F.R. 2015. Comparisons of Lygus lineolaris (Hemiptera: Miridae) populations from two distinct geographical regions of Mississippi. Environmental Entomology. 44(3):898-906.
Interpretive Summary: The tarnished plant bug (Lygus) is a significant pest of cotton in the southern USA. The boll weevil eradication program has resulted in a huge reduction in the amount of insecticides applied to cotton to control the weevils, going from more than 6 applications per year to zero. However, the number of insecticide applications to control tarnished plant bugs has more than doubled, from 1.5 per year to about 4 per year. In Mississippi cotton is grown in two very different agricultural regions. The Delta region comprises the Mississippi and Yazoo Rivers’ flood plain. The Hills region represents most of the remainder of the state. The tarnished plant bug is a more severe pest in the Delta where 3X the amount of insecticide is used per acre. This has rasied the question of whether tarnished plant bugs from the Delta and Hills are biologically different populations. Examination of some biological properties (egg laying, development time, hatch rate) in laboratory reared insects derived from the two regions did not show any differences that could be ascribed to their geographic origin. A genetic marker also failed to separate the regional samples.
Technical Abstract: Lygus lineolaris (Hemiptera: Miridae) is a major pest of cotton in the state of Mississippi. Economic data indicates that L. lineolaris is a more serious pest of cotton in the Delta region of Mississippi than in the Hills region, however, little data exists comparing the two populations. Two experiments were undertaken to compare L. lineolaris from these two geographically distinct regions. In the first experiment, colonies of L. lineolaris from each region were reared in the laboratory under controlled conditions and measurements of development time, survivorship, fecundity, and hatch rate were compared. The geographic region of origin had no effect on any of the variables measured, however, the diet used for rearing had a significant effect on all variables except hatch rate. In the second experiment the cox1 region of the L. lineolaris genome was compared between the two populations to examine the possible genetic differences between L. lineolaris from the two regions of Mississippi. Data revealed two cox1 clades in the Delta region and only one clade in the Hills region. Taken together, the data do not explain the reason for the differences in the severity of damage to cotton in the two regions. The effects of changes in integrated pest management (IPM) related to boll weevil eradication and Bt cotton as well as the effects of the differences in landscape ecology on populations of L. lineolaris between the two regions is discussed in this context.