Factors that Affect Flight Propensity
There was a lack of basic information required for effective detection and eradication of Anoplophora glabripennis (ALB). Current surveys in urban areas are estimated to be only 30% successful because of uncertainty about characteristics of ALB dispersal and capacity to spread. Adults are reported to be capable of flying several hundred meters in a single flight episode but could cover considerable distances over their lifetime. Other researchers investigated the distance, direction, and duration of flight in China using both mark recapture and radar tracking methods. Northern Research Station scientists concentrated on the proportion of the population that naturally initiates flight, and the factors that lead to flight initiation (including age, mating status, and host quality). This research was conducted in the Forest Service Quarantine Laboratory in Ansonia, CT.
Flight-tested adults were from laboratory strains or infested wood obtained from the Chicago (IL) or Queens (NY) infestations. Approximately, 30 males and 30 females were flight tested in each treatment. Each bioassay consisted of one to four adults on separate logs that were observed for 45 minutes. Adult preflight behavior, time of flight initiation, and type of flight were recorded. In the first experiment adult flight from Acer saccharum logs dried for three+ weeks and fresh cut were compared. Each individual in this experiment was flight tested four times during the adult stage (always on the same log type):
- At emergence, never fed, and unmated;
- One week after emergence, unmated, and fed;
- One day after mating and fed; and
- Three weeks after mating and fed.
In the next series of experiments adults were flown twice, first four days after eclosion, before mating and feeding and then again one week after mating. These experiments evaluated adult flight behavior under the following conditions:
- 15, 22, and 30° C (60 + 20% RH) using fresh cut logs,
- Air flow of 0.0, 0.5, and 1.0 m/s at 25° C (60 + 20% RH) using fresh cut logs, and fresh cut Acer saccharum logs with and without branches with foliage at 25° C (60 + 20% RH).
The final experiment compared adult flight between beetles from different infestations and at several points in their life time; four days after eclosion, seven days after initial feeding (still a virgin), at one day after mating, and weekly for five weeks after mating. This experiment used fresh cut logs and was conducted 25° C (60 + 20% RH).
We also assessed the likelihood of beetles taking flight after having encounters with the same sex, the opposite sex and a pair-bonded pair during reproductive behavioral observations.
Information on dispersal and capacity to spread that is fundamental to development of survey methods and protocols, and to determining establishment potential.
Males tended to fly more than females. A significantly higher percentage of females flew from dead host material than from fresh host material. Newly emerged and newly mated females were more likely to fly from fresh host material than one-week-old virgins or females mated for three weeks. Newly emerged males were more likely to fly from fresh host material than older or mated males. When disturbed, a higher percentage of both male and female beetles flew a longer distance than when they were allowed to initiate flight on their own. Adults of both sexes did not initiate flight at 15°C and propensity for flight tended to increase with temperature.
The results suggest that about half of the newly emerged adults of both sexes will fly from host material that has no twigs suitable for food. Well-fed females appeared to remain on a good-quality host and chew oviposition pits rather than fly. When the host quality is poor, >50% of females flew within the first 30 minutes and additional females would likely have flown after chewing pits and assessing host quality. Because > 85% of all males flew in this study, they would be expected to fly at some life stage regardless of host quality. Males were more likely to remain on a log than fly when they recently mated a female. Therefore, when populations are small and host trees are fresher, more males may fly in search of females while females likely would fly less than at higher population densities on deteriorating well-colonized hosts. However, beetles are more likely to disperse at higher temperatures which could make detection more difficult in warmer climates.
When males encounter each other and have a negative interaction, then there is a high likelihood that one male will take flight or at least move quickly away. This will also happen when one male is mounted on a female and leaves her to fight off the invading male. Females are less likely to take flight after encountering another female because the interactions are generally less violent than those between males. Females that encounter a pair and the male becomes aggressive may take flight.
Keena, Melody A. 2018. Factors That Influence Flight Propensity in Anoplophora glabripennis (Coleoptera: Cerambycidae). Environmental Entomology. 111: 181-. https://doi.org/10.1093/ee/nvy100.
Keena, Melody; Major, III, Walter. 2001. Anoplophora glabripennis (Coleoptera: Cerambycidae) flight propensity in the laboratory. In Fosbroke, Sandra L.C.; Gottschalk, Kurt W., eds. Proceedings, U.S. Department of Agriculture interagency research forum on gypsy moth and other invasive species 2001; 16-19 January 2001; Annapolis, MD. U.S. Dep. Agric. For. Serv., Northeast. For. Exp. Sta. Gen. Tech. Rep. NE-285, p. 81.
- Melody Keena, US Forest Service Northern Research Station Research Entomologist
- Walter Major III, US Forest Service – Northern Research Station Former Technician
- Jeff Horn, US Forest Service – Northern Research Station Former Technician
Last Modified: 08/06/2018