Influence of light on sound production behaviors in the emerald ash borer, Agrilus planipennis. Issue 10 (25th October 2018)

• Record Type: Journal Article
• Authors: Silk, Peter J.; Roscoe, Lucas E.; Brophy, Matt; Price, Jessica; Ryall, Krista L.
• Is Part Of: Entomologia experimentalis et applicata. Volume 166:Issue 10(2018:Oct.)
• Page Start: 844
• Page End: 853
• Publication Date: 2018-10-25
• Subjects: detection and management strategies -- communication -- acoustic signaling -- Coleoptera -- Buprestidae -- mating pair formation -- scanning electron microscopy; Entomology -- Periodicals; 595.7
• DOI: 10.1111/eea.12727
• Languages: English
• ISSNs: 0013-8703

Abstract

Abstract: Recent research has demonstrated that the emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), uses visual and chemical cues when locating potential mates and host trees. Here, we present the first evidence of the production of possible acoustic cues generated by adult males and females. We demonstrate for the first time that simultaneous wing opening and head 'pumping' in both males and females produce specific and distinct sounds. Acoustic recordings demonstrate that these sounds consist of a phrase comprising a 'click' generated by wing opening, followed by two separate chirps corresponding to the outward and subsequent inward movement of the head. Mean primary and secondary chirp durations were 0.332 ± 0.038 and 0.414 ± 0.046 s for males and 0.414 ± 0.046 and 0.389 ± 0.032 s for females, respectively. Overall mean phrase durations were 0.905 ± 0.114 s in males and 1.133 ± 0.133 s in females. Mean maximum phrase frequencies were 8 706.1 ± 141.1 and 7 885.0 ± 499.2 Hz in males and females, respectively. There were no significant differences in sound parameters between males and females. To determine whether these events were related to mating pair formation, we observed the occurrence of these events in adults paired with either another male or female and lone adults, and observed the number of mating pairs in copula formed during or shortly after sound production by either of the mating party. The mean number of sound‐generating events per min was significantly greater in males paired with females (0.75 ± 0.15) and/or other males (0.55 ± 0.23) vs. unpaired males (0.14 ± 0.06). Conversely, the mean number of sound‐producing events for lone females (1.4 ± 0.2) was significantly greater than for females paired with either males (0.49 ± 0.18) or other females (0.38 ± 0.10). No mating pairs in copula were formed during any of our observations. Scanning electron microscopy images showed the presence of possible pars stridens and plectrum structures on the ventral surfaces of the gula and pronotum in both males and females. Furthermore, we observed that the proportion of males and females exhibiting these specific behaviors were significantly greater under both halogen and incandescent light than under darkness, signifying the importance of light source or type on the production of acoustic signals. Although we did not find evidence of these behaviors being related to the courtship sequence, our results indicate the presence of a previously undescribed sound‐generation behavior in A. planipennis that is significantly influenced by light conditions. Abstract : A trap that utilizes attractive plant and pheromone volatiles to detect emerald ash borer (EAB) (Coleoptera: Buprestidae) adults is the principal method for monitoring EAB populations. This trap exploits visual and chemical cues used by EAB adults to locate host trees and one another. An additional, yet undescribed, sensory modality in EAB is the role of acoustic cues produced by adults. We describe for the first time the existence of quantifiable and detectable acoustic sounds generated by EAB adults.