Managing Insecticide Resistance in Onion Thrips

摘要: Management of onion thrips continues to be a high pest priority for Wisconsin onion growers. In 2006 the hot and dry conditions experienced in mid-summer led to increased populations that were very difficult to control in some areas. Furthermore, many of the earlier registered products for control of onion thrips are loosing control efficacy. Onion thrips insensitivity to λ-cyhalothrin (Warrior®) is suspected in Wisconsin similar to that which has been proposed in Ontario, Canada (Allen et al., 2005) and in New York populations using a thrips insecticide bioassay system (TIBS)(Shelton et al., 2003). Local insensitivity to Lannate® may also be occurring with increasing leaf damage following foliar applications and only ‘fair’control of thrips populations. As a result, onion thrips management should be a top priority along with the potential for onion thrips to spread Iris yellow spot virus (IYSV)(Gent et al., 2004). An improved understanding of the ecology and management of onion thrips on a broad scale is essential to develop methods of control for this pest and to develop effective resistance management plans.Onion growers in Wisconsin currently have a very limited range of insecticidal products available. Since the enactment of the Food Quality Protection Act (FQPA) in 1996, regulatory actions continue to threaten the long-term availability of the older, higher-risk compounds. FQPA is currently focused on the organophosphates and carbamates which effectively represent nearly half of the registered materials for onion thrips control. Furthermore, pending reviews may expand to include the synthetic pyrethroids as well. This will ultimately lead to a very …