Regional and Temporal Variation in Susceptibility to λ-Cyhalothrin in Onion Thrips, Thrips tabaci (Thysanoptera: Thripidae), in Onion Fields in New York

Abstract

Populations of onion thrips, Thrips tabaci Lindeman, from commercial onion fields in New York were evaluated for their susceptibility to the commonly used pyrethroid, lambda-cyhalothrin (Warrior T), using a novel system called the Thrips Insecticide Bioassay System (TIBS). To use TIBS, thrips are collected directly from the plant into an insecticide-treated 0.5-ml microcentrifuge tube that has a flexible plastic cap with a small well into which 0.08 ml of a 10% sugar-water solution with food colorant is deposited. The solution is sealed into the well with a small piece of stretched parafilm through which the thrips can feed on the solution. Thrips mortality is assessed after 24 h with the help of a dissecting stereoscope. In 2001, onion thrips populations were collected from 16 different sites and resistance ratios were >1,000 in five populations. Percent mortality at 100 ppm, a recommended field rate, varied from 9 to 100%, indicating high levels of variation in susceptibility. Particular instances of resistance appeared to be the result of practices within an individual field rather than a regional phenomenon. In 2002, we also observed large differences in onion thrips susceptibility, not only between individual fields but also between thrips collected in a single field at mid season and late season, again suggesting that insecticide-use practices within an individual field caused differences in susceptibility. Additional tests indicated no differences in susceptibility between adult and larval onion thrips populations and only relatively minor differences between populations collected from different parts of the same field. Using TIBS, several populations of onion thrips with different susceptibilities to lambda-cyhalothrin were identified and then subjected to lambda-cyhalothrin-treated onion plants. There was a highly significant positive relationship between percent mortality of thrips from TIBS and percent mortality from the treated onion plants, indicating that results from TIBS could be used to predict spray performance. These data suggest that use of TIBS for evaluating susceptibility to particular insecticides could be instrumental for developing a resistance management strategy for onion thrips.

Phylogenetic analysis based on mitochondrial COI gene sequences in Thrips tabaci Lindeman (Thysanoptera: Thripidae) in relation to reproductive forms and geographic distribution

“…The expansion of damage on the abovementioned crops and the decrease of insecticide susceptibility were all first reported in the late 1990s to early 2000s in Japan. Insecticide resistance in T. tabaci began to be reported in the late 1980s overseas (Cranshaw et al, 1989), and has recently become a serious problem (Shelton et al, 2003;Allen et al, 2005). These facts may suggest that different types of thelytokous strains invaded Japan during that period and caused agricultural problems; however, we need to analyze more overseas samples to clarify the relationship between Japanese and overseas populations.…”

“…In addition, reduced susceptibility of T. tabaci to insecticides has been observed in some areas of Japan (Morishita and Oue, 2001;Oida and Mihira, 2001;Nishimori et al, 2003;Murai, 2004). Recently, insecticide resistance in T. tabaci has been reported in the United States (Shelton et al, 2003) and Canada (Allen et al, 2005). These problems prompted us to consider that different strains have invaded Japan.…”

Onion Thrips (Thysanoptera: Thripidae): A Global Pest of Increasing Concern in Onion

“…In addition, some populations of T. tabaci have developed resistance to insecticides in several parts of the world (Martin et al 2003;Shelton et al 2003Shelton et al , 2006MacIntyre Allen et al 2005b;Herron et al 2008;Morishita 2008). Other studies have investigated the potential of other methods of control (biological control, host plant resistance, physical/mechanical control, and cultural practices) to reduce or contain populations of T. tabaci.…”

Pyrethroid-resistant onion thrips, Thrips tabaci Lindeman (Thysanoptera: Thripidae), infesting persimmon fruit

“…Failure to control with pyrethroids on T. tabaci in persimmon orchards suggested that thrips had developed pyrethroid resistance (Morishita and Oue, 2001); however, there are few reports on the susceptibility of T. tabaci against insecticides (Shelton et al, 2003), although the efficacy of insecticides has been determined (Mayer et al, 1987;Shimizu et al, 1994;Nishimori et al, 2003;Shibao and Tanaka, 2003).…”