Mortality of the invasive white garden snail Theba pisana exposed to three US isolates of Phasmarhabditis spp (P. hermaphrodita, P. californica, and P. papillosa).

Theba pisana is a serious snail pest in many parts of the world and affects diverse crops including grain, vegetables, grapevines, and ornamental plants and shrubs. Due to its gregarious nature, ability to reproduce rapidly, and the difficulty of controlling it by conventional methods, it has the potential to become a significant pest where introduced. Mitigating this pest is an important challenge that must be addressed. Phasmarhabditis hermaphrodita, is a gastropod-killing nematode that is commercially available only in Europe (Nemaslug ®) and Sub-Saharan Africa (Slugtech ® SP). The use of effective gastropod-killing nematodes in the genus Phasmarhabditis (P. hermaphrodita, P. californica and P. papillosa) in California may provide one strategy for alleviating the potential damage and further spread of these snails, which are currently limited to San Diego and Los Angeles counties. Laboratory assays demonstrated for the first time that US isolates of P. hermaphrodita, P. californica and P. papillosa at 150 DJs/cm2 caused significant mortality and are equally lethal to T. pisana. Molluscicidal efficacy of these nematodes are comparable with those of iron phosphate, at the recommended high dose of 4.88 kg/m2. Additional trials are needed to determine their effects at lower dose and whether they are dependent on the size or age of the snails.

Practical Pest Management Strategies to Reduce Pesticide Runoff for Argentine Ant (Hymenoptera: Formicidae) Control.

The purpose of this study was to involve pest management professionals in the design of application techniques and strategies that would be efficacious and also reduce insecticide runoff. Our study involved measuring both the efficacy of treatments for the Argentine ant, Linepithema humile (Mayr), and the concurrent runoff of fipronil and pyrethroids. Two collaborating companies used low-impact protocols for controlling ants while minimizing runoff. Protocol 1 involved bimonthly treatments, while Protocol 2 was monthly. Both protocols involved an initial treatment with a fipronil spray around the foundation. At the garage door-driveway interface, the fipronil application was done as a pin stream for Protocol 1, and as a crack and crevice application in the expansion joint near the garage for Protocol 2. Protocol 1 replaced most pyrethroid sprays with bifenthrin granules placed around bushes and away from the driveway. For the next treatment on day 63, Protocol 1 also included cyfluthrin spray treatments around the house foundation and crack and crevice applications around the edge of the driveway. For the first treatment in Protocol 2, the fipronil spray was supplemented with spot treatments of cyfluthrin. For subsequent Protocol 2 treatments, botanical insecticides were applied. For weeks 1 and 2 posttreatment combined, Protocol 1 had significantly higher reductions in ant numbers compared with Protocol 2. Thereafter there were no significant differences between the protocols. Runoff of bifenthrin from the granules used with Protocol 1 was much lower than in previous trials involving bifenthrin sprays. Day 1 fipronil runoff for Protocol 2 was significantly lower than that for Protocol 1. This difference may be because of the crack and crevice application applied in Protocol 2. Cyfluthrin runoff was minimal for Protocol 2, which involved spot treatments to supplement the fipronil on day 1, or the botanical insecticides for subsequent treatments. Protocol 1 had a large peak of cyfluthrin runoff at day 63 corresponding to their house and driveway treatments.