Evaluation of host plant resistance to thrips in cotton

Thrips were collected from seedling cotton, Gossypium hirsutum L, in Arkansas from 1998 to 2000 to determine the species composition within and among years. Adult thrips were collected using a whole-plant sampling technique. In 1998, Frankliniella fusca (Hinds) comprised at least 98% of the composition at Lonoke, Arkansas followed by Neohydatothrips variabilis (Beach) and Frankliniella occidentalis (Pergande). By 1999, F. occidentalis were more prevalent and had a range between 0 and 18.2% of the composition. No N. variabilis were identified. Similarly, F. occidentalis occurrence increased in 2000 up to 40% during one sample date. Thrips were also collected from Keiser and Rohwer, AR during 2000, where F. fusca was the most common species sampled followed by F. occidentalis in both locations. N. variabilis were only found at Rohwer in 2000.; Thrips population dynamics were described from adult and larval thrips collections from seedling cotton Lonoke, AR during 1999 and 2000. In both years, adult thrips were present on the cotton at emergence and generally declined as cotton developed. Rainfall was the most detrimental abiotic factor, clearly inducing population declines in both years.; Thirty-three cotton genotypes were evaluated for thrips feeding resistance or tolerance in Keiser and Rohwer, AR during 1999. These tests were conducted so that the most resistant or tolerant cultivars could be identified through an objective selection process for future evaluations. Cultivar selection was based on mean number of total thrips per five plants, damage rating and seed cotton yields for each cultivar. Terra 292 and Delta Pine 428 B were the most resistant cultivars and Delta Pine 458 BGRR was the most susceptible of the cultivars evaluated.; Commercially available, obsolete and foreign cotton genotypes were also evaluated in multiple locations for resistance or tolerance to thrips feeding. Cotton genotypes were evaluated in Lonoke, AR in 1998 and 1999, Keiser, AR in 1999 and Keiser and Rohwer, AR during 2000. Thrips were collected by using a whole-plant sampling technique and visual damage was rated on each sample date. Seed cotton yield was measured and agronomic potential was used to evaluate resistance characteristics. Paymaster 1560 BG, Paymaster 1215, Plains, Empire WR 61 and the Asiatic genotypes, A1 49 49 (Gossypium herbaceum L.) and A2 154 (Gossypium arboreum L.) exhibited resistance or tolerance to thrips feeding throughout several tests. These thrips feeding resistant/tolerant genotypes may be used in future breeding programs in order to enhance current integrated pest management techniques.; Reproduction and development of F. occidentalis (Thysanoptera: Thripidae) were evaluated on susceptible and resistant cotton genotypes. Asiatic cotton, accession A2-154 and Upland cotton (Gossypium hirsutum L.), cultivar Deltapine DP 458 BGRR were used as resistant and susceptible genotypes, respectively. No thrips pre-adult developmental differences were found between the two cotton genotypes. Adult longevity of thrips reared on Deltapine DP 458 BGRR was significantly greater that those reared on A2-154 with 18.6 and 15.1 days, respectively. Also, the average number of thrips larvae produced per day was significantly greater on Deltapine DP 458 BGRR.