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A survey was conducted to identify the thrips species associated with native terrestrial orchids in northern Florida. The above-ground plant structures were sampled when each species was flowering yielding adults of polyphagous species of the common flower thrips Frankliniella tritici (Fitch), Frankliniella fusca (Hinds), and Microcephalothrips abdominalis (Crawford). There is little indication that the orchids were reproductive hosts of these species. Other species of thrips that are more host-specific to orchids were collected and included adults of the orchid-living species Aurantothrips orchidaceus (Bagnall) and Pseudothrips beckhami Beshear and Howell. The presence of larvae of P. beckhami indicated the suitability of at least some orchid species as reproductive hosts. The adults of 2 predatory species in the Family Phlaeothripidae also were collected, Leptothrips mali(Fitch) and Karnyothrips melaleucus (Bagnall).

The thrips-borne tomato spotted wilt tospovirus is a serious economic threat to Georgia's flue-cured tobacco crop. Two thrips vectors, Frankliniella fusca (Hinds) and F. occidentalis (Pergande), are commonly encountered on tobacco foliage and blooms, respectively. Yellow sticky traps were monitored after a 48-h field exposure from March through June in 2003–2005 to assess thrips movement and species composition in the tobacco farm scape. During March each year there were similar numbers of F. fusca and the flower thrips complex [F.occidentalis, F. tritici (Fitch) and F. bispinosa (Morgan), combined] captured on sticky cards. During April, May and June, the flower thrips complex steadily became more abundant comprising around 60, 70, and 95% of the trap capture, respectively. Thrips vector species were captured throughout the entire sampling period. In April and May, F. fusca captures on stick traps related to F. fusca population densities on tobacco foliage. Some sampling periods had differences in thrips captures relative to a north, south, east, or west orientation, with each direction having the highest thrips numbers at least once each season. However, the overall seasonal mean capture was higher on the eastward direction all 3 yrs and on the westward direction on 2 of the 3 yrs, compared to the southern and northern directions. In a time-of-day study, very few thrips were captured between 1830 h and 0,700 h the following morning. Thrips movement increased in midmorning and peaked during midafternoon. It appears that sticky cards can be used to monitor early colonization of thrips species in tobacco fields plus monitor thrips movement throughout the day, thus providing information on when potential vectors arrive and move within the field. Sticky trap monitoring provides an alternative to direct plant observation for predicting thrips abundance on tobacco foliage and the need for thrips controls.

The common species of thrips that are considered pests of cotton, Gossypium hirsutum (L.), include flower thrips, Frankliniella tritici (Fitch); tobacco thrips, Frankliniella fusca (Hinds); western flower thrips, Frankliniella occidentalis (Pergande); onion thrips, Thrips tabaci (Lindeman); and soybean thrips, Neohydatothrips variabilis (Beach). Thrips feeding on cotton seedlings can inhibit plant growth, reduce plant stand, delay crop maturity, and reduce seed-cotton yield. Surveys were conducted in Alabama, Arkansas, Georgia, Louisiana, Mississippi, and Tennessee to determine the thrips species infesting cotton seedlings during 1996 to 1999. Cotton seedlings were sampled weekly between 7 and 48 days after plant emergence at one to four field sites in each state. Over 12,000 thrips adults were collected using plant washing procedures with 9,005 individuals mounted on slides, and identified to species. The tobacco thrips was the most common species collected in all states, except Georgia, and comprised at least 63% of the thrips adults in all instances, except four. The occurrence of flower thrips and soybean thrips was variable; however, neither species accounted for more than 21% of thrips identified in each state. Western flower thrips accounted for less than 15% of adults collected in all instances except two (28% and 30%) in Louisiana. Also, individual specimens of Thrips nigropilosus Uzel and Anophothrips obscurus Müller were collected in Alabama, and several specimens of Microcephalothrips abdominalis (Crawford) were collected in Arkansas and Louisiana.

Field experiments were conducted in 1997–1999 in Washington Co., NC, to examine how cotton, Gossypium hirsutum, is affected by thrips species composition and abundance, environmental factors, and insecticide applications. Populations of adult and juvenile thrips were monitored in seedling cotton treated with insecticide applications of either imidacloprid as a seed treatment, acephate as a foliar spray, or aldicarb applied in-furrow. The number of plants per 3.05 row-m, location of the first fruiting branch, number of open bolls per 1.52 row-m, yields, accumulated degree-d 60′s (DD60′s), and accumulated rainfall were recorded each year the studies were conducted. Aldicarb and acephate provided better thrips control than did imidacloprid in all 3 yrs. Thrips species ratios differed among years. In 1997, the aldicarb treatment resulted in a better “earliness profile” (lower fruit set and more early opening bolls) than either acephate or imidacloprid, while in 1998 and 1999 there were few differences in these plant parameters. In 1997, all insecticide treatments resulted in statistically higher yields compared with the untreated check. Accumulated DD60′s were consistently higher in 1998 and 1999 than in 1997 after the first thrips sampling date. Cumulative rainfall appeared to be inversely associated with juvenile thrips populations.

The response of flower thrips, Frankliniella spp., to various colors and sticky trap designs was evaluated in staked tomato fields in western North Carolina. Yellow sticky traps caught significantly more thrips compared with blue or white traps. There were no differences in the relative proportion of thrips species caught on different colored traps. The size of the flower sampling unit (i.e., 10-flowers versus all flowers per plant) did not influence the correlation between sticky trap catches and thrips abundance in flowers. Only F. occidentalis (Pergande) exhibited a significant correlation between percent abundance on all colors of sticky traps and percent abundance in flowers. Colored sticky traps caught high numbers of F. tritici (Fitch), despite the fact that few F. tritici were collected from flowers. In tests to evaluate different trap designs, cylindrical and cup traps caught more F. tritici than glass slide traps. Cylindrical sticky traps were more economical and enabled easier identification of thrips than glass slide or cup traps.

Three thrips species were commonly found in western Arkansas and northeast Oklahoma cowpea fields during the 1991 and 1992 growing seasons. These were the tobacco thrips, Frankliniella fusca (Hinds), the flower thrips, Frankliniella tritici (Fitch), and the soybean thrips, Sericothrips variabilis (Beach). Earlier planted cowpea fields in each area had higher thrips numbers than later planted fields. Tobacco thrips numbers tended to be higher during the early stages of the crop when the plants were small. As plants began to produce blooms, flower thrips numbers increased considerably. Peak flower thrips numbers typically occurred around two weeks after first bloom. Soybean thrips abundance was generally lower than the other common species and had no apparent pattern. Chirothrips crassus Hinds and Chirothrips spiniceps Hood also were found, but were uncommon.

Cosmetic fruit damage on tomato recently has resulted in downgrading and cullout of freshmarket fruit in the southeastern U.S. The damage consists of small indentations that are sometimes surrounded by a light-colored halo; it began at the same time that western flower thrips, Frankliniella occidentalis (Pergande), populations moved into the geographical area. In addition to F. occidentalis, populations of other Frankliniella spp. commonly inhabit tomato flowers in the region. An understanding of the cause of the damage and its association with Frankliniella spp. is necessary to implement management programs. The objectives were to determine if thrips species inhabiting tomato flowers cause the newly observed cosmetic damage, and to determine the relationship between number of scars per fruit and thrips densities on tomato flowers and small fruit. Results showed that damage was caused by oviposition of female F. occidentalis inhabiting either flowers or small fruit. Other Frankliniella species were not found to cause cosmetic fruit damage. The relationship between the number of scars per tomato fruit and density per flower of F. occidentalis was evaluated by using regression. The relationship was quadratic, although the amount of variation explained by the model was very low (r2 = 0.07). Our research revealed that management efforts should focus on reducing populations of female F. occidentalis to nondamaging levels.