Submitted to: Mid-South Entomologists online journal
Publication Type: Abstract Only
Publication Acceptance Date: January 10, 2008
Publication Date: January 10, 2008
Citation: Snodgrass, G.L. 2008. Role of Diapause in the Utilization of Fall and Winter Hosts by the Tarnished Plant Bug in the Mid-South. Mid-South Entomologists online journal. Technical Abstract: Tarnished plant bugs, Lygus lineolaris (Palisot de Beauvois), overwinter as diapausing adults throughout North America. Because of the importance of diapause in the development of control methods for plant bugs, diapause in the tarnished plant bug was studied from 1999-2007 in field and laboratory tests at the Southern Insect Management Research Unit, USDA-ARS, Stoneville, MS. Stoneville is at a latitude of 33.43 N and is in Washington County near the western edge of MS in the Mississippi River Delta. Tarnished plant bugs are native to North America, and in the mid-South they have evolved a diapause that enables them to survive periods when food is unavailable, and take advantage of favorable conditions for reproduction in the fall and winter when they occur. Tarnished plant bugs begin entering diapause in late August and by 12 September about 50% of the developing nymphs will produce diapausing adults. Most nymphs developing in the field in October and November become diapausing adults. However, reproduction in the fall continues in the field on weed hosts until the hosts are killed by a freeze. Reproduction can also occur during the winter with new generation adults produced in March in mild winters. The key to tarnished plant bugs being able to utilize favorable periods of weather for reproduction in the fall and winter in the mid-South lies in two factors. One is the presence of winter hosts (mainly henbit, Lamium amplexicaule L.) that bloom in late November through March. The other is the ability of diapausing adult tarnished plant bugs to break diapause in response to temperature and food stimuli. Both of these two stimuli are important, and food must contain nutrients as are found in blooms or flower buds. The laboratory and field tests that determined the importance of food and temperature in emergence of plant bugs from diapause and how this makes plant bugs so well adapted to their environment in the mid-South will be presented and discussed.