Efficiency of Flight Interception Traps for Adult Colorado Potato Beetles (Coleoptera: Chrysomelidae)

Abstract

Interception traps have been used to monitor and sample Colorado potato beetle, Leptinotarsa decemlineata (Say), populations in flight, but the efficiency of these traps was unknown. The efficiency of interception window traps is limited because flying adults avoid the traps and may bounce off the trap without being collected. All trap types tested were avoided in flight chamber tests, including those constructed of transparent Plexiglas or yellow wood boards. A larger screen trap and a harp trap designed to reduce detection were also avoided by the beetles in flight. None of the traps provide a direct estimate of the number of adults randomly flying in the trap area. The highest level of efficiency for window traps was obtained with the yellow trap, which caught 16% of the expected flying population. Harp and screen traps without frames intercepted 60-62% of the expected flying population. The presence of a frame did not increase significantly the avoidance of the screen and harp traps by beetles in flight. Recommendations are made to maintain or increase the efficiency of some traps.

Adult Density and the Rate of Colorado Potato Beetle (Coleoptera: Chrysomelidae) Flight Take-Off

“…An average of 35.0% (SE Ϯ 5.64) of the adult beetle population in these experiments ßew from the release cone during the 3 h. Contrary to expectations, ßight take-off rates tended to decrease at the highest density tested. This was probably because adult beetles started to interfere with each other on top of the release cone while warming up their ßight muscles and extending their wings before take-off (Boiteau 2000).…”

“…At another level, dispersal of adult Colorado potato beetles by walking and ßight results in the colonization of host plants as far away as 1Ð2 km from overwintering sites or areas with a depleted food source Ferro 1990a, Weisz et al 1996). The relative importance of ßight and walking in population recruitment is very variable (Boiteau et al 1994, Ferro 1995, Weber et al 1995, Boiteau 2000, but ßight can be at least as important as walking (Boiteau 2000).…”

“…For example, the adult Colorado potato beetle has evolved a complex behavioral sequence for ßight take-off (Boiteau 2000) that requires warm temperatures to initiate ßight activity. Flight muscles must be warm enough to produce muscular power sufÞcient for wings to beat with an amplitude and frequency that will elevate the adult beetle above the substrate (Johnson 1969, Holliday andParry 1987).…”

Vertical distribution profile of Colorado potato beetle [Coleoptera: Chrysomelidae] in flight above host, resistant host and non-host fields

“…'Harp' style interception traps (Boiteau 2000) were used to capture CPB in flight. Harps were constructed using 1 m strands of clear fishing line (6 lb test Maxima, Santa Anna CA) hung vertically and strung 1 cm apart.…”

“…Groups of 20 to 40 adult CPB were field collected and placed on a flight release apparatus consisting of a Styrofoam cone (12.5 cm diam base by 30.5 cm high) in a 2 L plastic container lined with Fluon to prevent beetles from walking out (Boiteau 2000). The flight release apparatus was elevated so that the top of the cone reached canopy height and was placed at the center of a 20 m diam observation arena.…”