Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/5/2005
Publication Date: 6/5/2005
Citation: Setamou, M., Showler, A., Reagan, T.E., Jones, W.A., Bernal, J.S. 2005. Leptodictya tabida (Hemiptera: Tingidae): A potential threat to sugarcane production in Lower Rio Grande Valley of Texas. Journal of Economic Entomology. 98(3):1018-1023. Interpretive Summary: Sugarcane is an economically important commodity that grosses about $65 million in the Lower Rio Grande Valley of South Texas. Many insect pest species are found damaging plants in sugarcane fields. Thus far, two lepidopteran species i.e., the Mexican Rice Borer and the Sugarcane Borer, are reported as the most damaging insect pests probably because of their feeding behavior that directly affects sugar accumulation in plants. In recent years however, the sugarcane lace bug emerged as a new threat to sugarcane production. Infestations and feeding of lace bugs result in leaf discoloration leading to a reduction of photosynthesis and sugar accumulation in stalks. As part of a program to assess the importance of this emerging pest, surveys and field experiments were conducted in three counties of the Lower Rio Grande Valley in 2001 and 2002. Sugarcane lace bug was found in all fields sampled with more than half of the plants affected per field. No natural enemy was collected on this pest; however field experiments showed differences in the susceptibility of sugarcane cultivars to this pest. Therefore, host plant resistance could be used to reduce the incidence of the sugarcane lace bug in south Texas.
Technical Abstract: Areawide surveys and replicated cultivar trials were conducted in 2001 and 2002 in sugarcane fields in the Lower Rio Grande Valley of Texas to assess the distribution and incidence of the sugarcane lace bug, Leptodictya tabida Herrich-Schaeffer. Leptodictya tabida was found in all fields surveyed during both years, infesting 60% and 68% of the plants, respectively. The average percentage of leaves infested was 11% in 2001 and 15% in 2002. In 2001, the cultivar CP70-1133 was the most infested, CP72-1210 was the least infested, and intermediate infestation levels were evident in CP70-321 and TCP87-3388. In 2002, however, TCP87-3388 and CP70-321 were more heavily infested, and CP71-1240 and CP71-1405 were the least infested. Mean densities of L.tabida recovered per plant varied between 1.2 bugs on CP72-1210 and 5.1 on CP70-1133 in 2001, and in 2002, from 0 bugs on CP71-1240 and CP71-1405 to 5.3 on CP72-1210. In the cultivar trials, cultivar differences were also evident in both plant and leaf infestation levels, and the proportion of immatures to total L.tabida populations; HoCP91-555 had the lowest L.tabida infestations and NCo-310 had the greatest levels in both years. Although > 5,000 L.tabida from the field were collected and kept in the labortatory, no parasitoids were found. The distribution of the infestations during the surveys and in the field trial evaluations suggested that L.tabida populations have been spreading in Lower Rio Grande Valley sugarcane. Potential varietal resistance mechanisms are discussed.