Influence of wind conditions and intertrap spacing on pheromone trap catches of male European pine sawfly, Neodiprion sertifer

Abstract

The spatial distribution of catches of male European pine sawfly, Neodiprion sertifer (Geoffr.) (Hymenoptera, Diprionidae), was studied using different pheromone trap arrays. In hexagonal trap groups, trap interference was evident by reduced catch in the central of seven traps spaced 10 to 40 m apart. When the trap spacings were either 5 or 80 m no significant reduction could be shown. The interaction was more pronounced for strong (100 μg) pheromone ([2S, 3S, 7S]‐3, 7‐dimethyl‐2‐pentadecanyl acetate) lures than for weak ones (10 μg). Similarly, the inner traps caught less than the outer traps in grids of 6 × 6 traps spaced 20 or 50 m apart. Mark‐release‐recapture experiments in the grid array confirmed that a majority of the males originated from outside the trap group and were caught in the first trap they encountered. There were no differences between catches in downwind, crosswind and upwind traps. Thus, no ‘overshooting’ was evident during average conditions, i.e. the sawflies did not divert from the trap initially attracting them by flying to the upwind trap. However, the proportion caught in the upwind traps increased with increasing wind velocity, suggesting more overlapping pheromone plumes at higher wind speeds. Also, the recapture rate of released males increased with increasing wind velocity up to a daily average of 3.1 m/s at 2 m, indicating that sawflies more easily find the pheromone source, probably due to a more stable pheromone puff trajectory during higher wind velocities. The application of pheromone traps in e.g. monitoring studies is discussed and a distance of at least 50 m between the traps with strong lures used in the present study is recommended to avoid trap interaction.

Maximizing Information Yield From Pheromone-Baited Monitoring Traps: Estimating Plume Reach, Trapping Radius, and Absolute Density ofCydia pomonella(Lepidoptera: Tortricidae) in Michigan Apple

“…The regularity of such dispersal can be measured by superimposing a dense grid of traps over the mover population after allowing it time to disperse from a single point. Indeed, symmetric dispersion from a single release point has been reported for codling moth (Worthley 1932), pine saw fly ( Neodiprion sertifer ) (Wedding et al 1995, Östrand and Anderbrant 2003), oriental fruit moth ( Grapholita molesta ) (Ellis and Hull 2013), and painted apple moth ( Teia anartoides ) (Guichard et al 2010). We are aware of no insect studies yielding notably skewed dispersive disks that would falsify the random walk model of search for pheromone plumes.…”

From where are insects recruited? A new model to interpret catches of attractive traps

“…A positive relationship between recapture and wind speed has been reported for N. sertifer (Wedding et al, 1995). In that study, males were released on different sides of one to several traps, thus it is difficult to know what proportion of the catch had flown upwind vs. that that had been transported downwind.…”

“…We collected data on wind speed and direction, temperature and precipitation as these are the main parameters that had earlier been shown to affect flight by N. sertifer males (JoÈ nsson & Anderbrant, 1993;Wedding et al, 1995;O È strand et al, 2000;O È strand et al, 2001). The wind speed and direction data were correlated (e.g.…”

Effect of Trap Orientation and Interval Distance on Captures of Isoceras sibirica Alpheraky (Lepidoptera: Cossidae)

“…The interference between traps occurred when intertrap distances were shorter than 30 m, the reason is that the short distances among traps can lead to competition among the pheromone plumes of neighboring traps (Wedding et al, 1995;Wall & Perry, 1982;Bacca et al, 2006;Elkinton & Cardé, 1988).…”