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A novel attract-and-kill trap for olive fruit fly, Bactrocera oleae (Rossi) (Diptera: Tephritidae), was constructed with yellow corrugated plastic in an inverted cylindrical pan shape formed from a disk and collar. The trap components were tested under three greenhouse temperatures and humidities of warm, hot, and very hot for attractiveness to caged young or older adults. A greater proportion of adults regardless of age were found underneath the devices including disks, cylindrical pans, and pans with pheromone lures and test units of cylindrical pans sprayed with water, insecticidal bait spray, and with lures. The effect was related to lower temperatures on the underside compared with the top and the intolerance of the pest to heat. A circular collar added to the perimeter of the disk that formed the top of the inverted cylinder made the attract-and-kill trap more attractive to adults than the disk alone. Pheromone lures or bait sprays did not increase adult attraction, so were not needed for efficacy. The cylindrical pan was especially attractive to adults when temperatures were high by providing shelter from the heat. At very high temperatures, the pan became unattractive, possibly due to heating of the construction materials. Cylindrical pans sprayed with water on the underside attracted the highest number of adults especially at high temperatures. Greenhouse tests showed that the inverted cylindrical pan design has potential as an attract-and-kill device for olive fruit fly control.

An adult female olive fruit fl y deposits an egg into olive fruit.As temperatures surpass 84°F, adult fl ies become increasingly agitated and egg laying is halted, and above 95°F they are motionless. Marshall W. Johnson30 CALIFORNIA AGRICULTURE • VOLUME 65, NUMBER 1 suggest that adults seek and remain near moisture sources as temperatures approach and surpass 95°F.Reduced adult fly activity can result in lower trap counts in the field while maximum daily temperatures remain around 95°F to 99°F and the flies have access to adequate water and carbohydrate sources (Wang et al. 2009a). However, as the frequency at which daily maximum temperatures equal or surpass 100°F increases, greater numbers of adults will die due to heat stress, especially when they cannot access adequate quantities of water and food (Wang et al. 2009a, b) (fig. 2). Although adult females may ingest liquid from punctures they make in olive fruit, this secretion does not provide the needed carbohydrates to help them survive heat-induced stress (Johnson and Nadel, unpublished data).One might assume that acquisition of adequate amounts of food and water would be easy for olive fruit fly adults, which are strong flyers. Using a customdesigned flight mill, Wang et al. (2009b) reported that adults of both sexes held for 7 days at 75°F (constant temperature) and provided with ample food (honey and hydrolyzed yeast) and water, were able to fly uninterrupted for an average of 2,164.8 ± 228.8 yards during a mean period of 1.54 ± 0.16 hours ( fig. 3).Nonetheless, heat stress and lack of water and food can affect flight ability. Olive fruit fly adults that were subject to the same conditions as described for 7 days and then to water only or no food and water in diurnal temperature regimes (65°F at night; 95°F or 100°F during the day) for 24 hours before the flight test did not perform as well as the control group ( fig. 3). All stressed groups of tested flies flew significantly shorter distances (≥ 42%) than the control (F 6,252 = 62.7, P < 0.01). Additionally, individual flies that were denied food and water from the time that they emerged as adults and were held at either 65°F at night and 95°F, or 100°F, during the day for 1 to 2 days, flew significantly shorter distances (≥ 92%) than the flies provided no food and water for 24 hours after having access to food and water for 7 days ( fig. 3).In a worst-case scenario, an adult fly that emerges in mid-August in the Central Valley may commonly experience maximum daily temperatures over 100°F for 3 consecutive days (LynnPatterson 2006). Without food or water immediately available, an adult will only be able to fly an average of 16.4 ± 4.4 yards to locate these resources in a dry and unexplored landscape. Such a fl y would have an 84% chance of dying in the fi rst 24 hours, and of those that did survive only about 25% would be able to fl y (Wang et al. 2009b). Additionally, when olive fruit fl y adults were held at 65°F at night and 95°F or 100°F during the day over a 3-day period with either water alone...

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