Upwind anemotaxis in response to cue‐lure by the Queensland fruit fly, Bactrocera tryoni

Abstract

Summary Movements of mature male Bactrocera tryoni (Froggatt) (Diptera: Tephritidae) were observed individually in a wind tunnel under conditions of ‘cue‐lure with wind’, ‘cue‐lure with no wind’, ‘wind only’ and ‘no wind or cue‐lure’. Further observations were made using a dense foliage array in the wind tunnel and a structured plume of cue‐lure. Patterns of walking or flying were essentially the same in all of the first four treatments except that in the ‘cue‐lure with wind’ treatment, over half of the flies moved in a consistent track upwind for at least 400 mm at some time during the first 5 min of observation. With clean wind, only 10% of the flies did this. The result was that mean net upwind displacement after 5 min in the ‘cue‐lure with wind’ treatment significantly exceeded that in the other three treatments, the results of which did not differ significantly from each other. The upwind tracks were accomplished by either walking or flying (with or without stops) or by a combination of both. When the wind tunnel was filled with a dense foliage array, the results with cue‐lure laden wind were similar to those obtained with the equivalent treatment without foliage, except that upwind tracks were predominantly in short stages. When flies were exposed to a structured plume of cue‐lure odour (without foliage present), they did not apparently alter their behaviour on leaving or entering the plume, but some did make consistent upwind tracks while they were in the plume.

Investigation of the Physiological Consequences of Feeding on Methyl Eugenol byBactrocera cacuminata(Diptera: Tephritidae)

“…The natural occurrence of others, such as cuelure and trimedlure, is less clear (Drew 1987). It is known that some of these chemicals elicit strong chemotactic feeding responses in male ßies Hartland 1999, Meats andOsborne 2000). However, despite extensive studies of feeding and mating behavior in fruit ßies (see reviews in Aluja and Norrbom 2000), the precise ecological role of these parapheromones remains an enigma.…”

Behavioral responses of Chrysomya megacephala to natural products

“…This reason was supported by observation in the first experiment, in which some flies showed a positive anemotactic response to the wind in the tunnel when it was not contaminated with any odor. This phenomenon was also found in the mosquito, Anopheles gambiae (Diptera: Culicidae), which generally flies upwind in wind tunnels, even in the presence of only clean air (Costantini et al 2001), the Queensland fruit fly, Bactocera tryoni (Diptera: Tephritidae), where 10% of the flies responded to clean wind with anemotaxis (Meats and Hartland 1999), and the mite, Phytoseiulus persimilis (Acari: Phytoseiidae), where starved females responded to an air flow by means of positive anemotaxis despite odors being present or not (Van Tilborg et al 2003). In addition, it may be that the turbulence and force of the wind current in the wind tunnel directly affected the odor plume in the wind tunnel and simultaneously affected the navigational ability of flies.…”

Influence of male aggregation size on female visitation in Bactrocera tryoni (Froggatt) (Diptera: Tephritidae)

“…A recent study investigating upwind movement in response to airborne pheromone in B. tryoni found no significant response by males or females to pheromone produced by a mean of 6.27 pheromone-calling males per observation (Pike & Meats 2003). Meats and Hartland (1999) found that adult male B. tryoni possess only a limited capacity for mechanoreceptive anemotaxis, with movement only occasionally in response to both wind and the odour of cue-lure.…”

“…A recent study on B. tryoni found that male calling is not always associated with male mating success (Weldon 2005). Given the relatively poor capacity for B. tryoni to locate an odour source (Meats & Hartland 1999;Pike & Meats 2003), it is not surprising that male pheromonecalling may not be the only cue used to encounter mates. It has been suggested that pheromones only operate at small scales within a tree canopy to attract females and induce conspecific males to remain in the vicinity of the pheromone source (Pike & Meats 2003).…”