Characterization and Application of Semichemical-Based Attract-And-Kill to Suppress Cabbage Looper, Trichoplusia Ni (Hubner), Populations in Commercial Vegetable Greenhouses

Objectives: 1. assess parameters of a paste (Last CallTM CL) containing insecticidal permethrin and pheromonal (2)-7-dodecenyl acetate (27- 12:OAc), and of modified paste, containing five floral semiochemicals and; 2. determine whether deployment of modified paste reduces crop damage inflicted by cabbage loopers, Trichoplusia ni, in commercial greenhouses. In trapping experiments, droplets with 2 or 8% of 27-12:OAc were equally effective, and more effective than droplets with 0.2'36, in attracting male T. ni. Traps baited with a live female T. ni or with a droplet containing 8% of 27-12:OAc captured similar numbers of males. Droplets with floral semiochemicals (1 6%) plus droplets with 27-1 2:OAc (8%) as trap baits were more effective than floral semiochemical droplets alone in attracting males but not females. Floral semiochemical droplet baits attracted more females but not more males than 27-12:OAc. Platforms carrying droplets with 27- 12:OAc (2%) and droplets with floral semiochemicals (16%) were contacted by 1 1 out of 42 male T. ni and 13 out of 39 female T. ni released into the compartment, whereas control platforms without droplets were not contacted. Honey bees, Apis mellifera, were observed not to contact droplets with or without floral semiochemicals. To address the second research objective, treatment and control stimuli were randomly assigned to 16 greenhouse compartments (0.1-2 ha). The treatment consisted of 800 droplet pairs per hectare placed on platforms above pepper crop canopies, with one droplet per pair containing Z7-12:OAc and the other containing floral semiochemicals. Droplet pairs in control compartments did not contain attractants. Floral semiochemical and 27-1 2:OAc droplets were replaced every 4 and 8 weeks, respectively. Every 4 weeks for 20 weeks, five criteria were assessed. Mean numbers of T. ni eggs, larvae, and pupae were significantly lower in treatment than in control compartments. Plant damage in control unlike treatment compartments continuously rose. The treatment effect is significant as control compartments were not true controls, with growers applying tactics against 7'. ni eggs and larvae. The attract and kill tactic targets T. ni adults and is complementary with tactics aimed at eggs or larvae. It may become part of T. ni control in commercial greenhouses.