|TUELHER, EDMAR - Universidade Federal De Vicosa|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 2/1/2017
Publication Date: 4/18/2017
Citation: Tuelher, E., Cervantes, F.A., Backus, E.A. 2017. Quantifying Lygus lineolaris stylet probing behavior and its damage to cotton leaf terminals. Presented at International Heteroptera Symposium, April 18-20, 2017, in Seaside, CA.
Technical Abstract: Lygus lineolaris is a serious pest inducing feeding damage on an array of crops; on cotton, lygus bugs feed on both leaves and squares. When lygus bugs feed on cotton leaves, younger leaves at cotton axials and terminals are preferred; resulting damage may compromise plant growth. Because L. lineolaris uses a cell rupturing strategy to feed on plants, it was hypothesized that: (1) the degree of damage is related to amount of insect feeding and (2) this damage is related to insect life stage. Electropenetrography (EPG) was used to quantify L. lineolaris stylet probing behavior on immature cotton axial leaves and digitally quantify insect damage by measurements of foliar damaged areas. Third, 4th, and 5th instars plus adults were wired and allowed to feed for 16 hours on cotton terminals with simultaneous data acquisition by EPG, to recognize and quantify probing waveforms (cell rupturing [CR], transition [T] and ingestion [I]. After insect feeding, pictures of the leaves were taken and the areas of feeding-derived necrosis were measured at two time intervals after feeding. The results showed that the CR waveform, representing combined stylet movements and salivation during insect probing, is associated with damage on cotton axial leaves; there was a strong correlation between total time spent in CR waveform and the area of damage on leaves. The highest amount of foliar damage, as well as duration of CR, were found for 4th instars and the lowest damage and duration of CR was for adults. However, most adult insects did not perform the T waveform during probing, suggesting a different probing behavior on axials, compared to other life stages, and also compared to adult feeding on cotton bolls. Thus, details of stylet probing behavior of cell rupturing-feeding by L. lineolaris will help to understand the cause of damage to plants and, consequently, aid in development of strategies to reduce crop loss.