Effect of Wind Speed on the Pheromone-Mediated Behavior of Sexual Morphs of the Potato Aphid, Macrosiphum euphorbiae (Thomas) Under Laboratory and Field Conditions

Abstract

The effect of wind on the potato aphid, Macrosiphum euphorbiae, male responsiveness to the sex pheromone, and on the calling behavior of virgin oviparae, was studied under constant wind speeds in the laboratory and in the field. A significant proportion of females called at wind speeds up to 4 m/sec, whereas male flight behavior in clean air was inhibited at velocities > 2 m/sec. However, males continued to walk over the range of wind speeds at which females called. Under constant wind velocities in a wind tunnel, males downwind of calling females oriented on the upwind edge of the release stand, and fewer individuals took flight at low constant wind speeds than in a clean air plume. In all cases, whether calling females were present or not, the males that took flight moved downwind. However, when a bridge was available, a significant proportion of males walked upwind to the pheromone source. The same orientation and walking behaviors were observed when males were placed downwind of calling females under variable wind conditions in the field. However, contrary to the laboratory results, 30% of the males tested flew upwind and landed on the source. A more detailed examination found that males orienting toward a source would walk if wind speeds were high but initiated flight in an "upwind" direction if there was a lull in wind velocity. These findings suggest that for the potato aphid, and probably for many other insect species with weak flight capacity, walking behavior is a significant component of pheromone-mediated mate location. This would permit males to continue foraging for calling females in the vicinity when wind velocities inhibit flight.

Virus infection influences host plant interactions with non‐vector herbivores and predators

“…). However, aphids are generally not attracted to plants via volatile cues at this range due to an inability to orient while in flight (Nottingham & Hardie ; Goldansaz & McNeil ; reviewed in Powell, Tosh & Hardie ; Webster ). In contrast, both alate and apterous aphids make extensive use of volatile foraging cues when walking (e.g.…”

Weather Forecasting by Insects: Modified Sexual Behaviour in Response to Atmospheric Pressure Changes

“…However, it is not unreasonable to think that males also respond to the changes in atmospheric pressure for the same reasons suggested for females. Winged male are very poor fliers and flight initiation is inhibited at low windspeeds [39], so once blown off the plant they would have little chance to relocate overwintering hosts with receptive oviparae.…”

The role of olfaction in aphid host location

“…Winged morphs are also produced on the secondary host in response to overcrowding (Sutherland, 1969). Aphids are relatively weak flyers and will not attempt to fly unless wind speeds are fairly low (Kennedy, 1990; Hardie et al , 1996; Goldansaz & McNeil, 2006), but wind tunnel experiments have shown that flying aphids are capable of making targeted landings on plants or leaf‐sized yellow or green targets under low wind conditions (Storer et al , 1999; Vargas et al , 2005; Goldansaz & McNeil, 2006).…”

“…Because of their weak flying ability (Kennedy, 1990; Hardie et al , 1996), walking may be a safer and more reliable way of travelling short distances. Sexual males of Macrosiphum euphorbiae will preferentially walk towards the odour of a nearby calling females rather than fly, when presented with a wire path to walk along, if wind speeds are above 2 m s −1 (Goldansaz & McNeil, 2006). Summer migrants quickly lose the ability to fly after landing on a new host as a result of autolysis of the flight muscles.…”