Submitted to: Palynology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 11/11/2011
Publication Date: 3/26/2012
Citation: Jones, G.D., Allen, K.C. 2012. Pigweed pollen retention in laboratory-reared tarnished plant bugs. Palynology. DOI:10.1080.01916122.2012.662178. Interpretive Summary: The tarnished plant bug (TPB) is an important economic pest throughout the Cotton Belt. Although TPB ingest wild host plants when cultivated crops are not flowering, new information is needed on the distribution of TPB after they have infested cotton, corn, and other crops. Pollen analysis has been used to identify food sources and dispersal patterns of several insect species other than TPB. In a preliminary study of pollen retention by TPB, laboratory-reared TPB were allowed to feed on the flowers of pigweed for 72 hours. Pigweed pollen was found in 100% of the TPB for up to 3 hours after feeding on pigweed flowers. Some pigweed pollen was found in TPB for up to 96 hours after feeding. Determining the retention of pollen from various wild plant hosts by TPB will help pest managers identify temporal changes in the landscape distribution of TPB.
Technical Abstract: Wild host plants play an important role for tarnished plant bug (TPB), Lygus lineolaris, populations during the early spring and during the fall when cultivated crops are not flowering. Determining TPB dispersal into and out of cotton fields and native habitats is important for managing this insect pest. The use of pollen analysis has not been previously conducted on these insects. As a preliminary study, we wanted to determine in pollen analyses could be used to determine the food sources and dispersal of these insect pests. Rinsing the insects three times with 95% ethyl alcohol (ETOH) prior to acetolysis of the insects removed 99% of the external pollen. There was a significant reduction in the number of pollen grains found in acetolyzed adults from the 0 time interval to the 96 hour time interval. At 0, 1, and 3 hours, 100% of the TPB contained pollen, and at 96 h, 55% of the TPB examined contained pollen. Overall, 89% of the TPB examined contained pollen. Insects examined a 0 h contained the greatest number of grains (757) and those at 96 h contained the least (26). If a TPB is examined and contains more than 10 pigweed pollen grains, there is a high probability that this individual fed on pigweed within 12 hours. Determining the pollen retention of various wild hosts in the gut helps in the management of this insect pest because it gives entomologists a time frame and a way to “track” these insect pests.