@article {57933, title = {Effects of artificial light at night and male calling on movement patterns and mate location in field crickets}, year = {2019}, abstract = {

Anthropogenic factors, such as artificial light at night (ALAN), are increasingly linked to significant modifications in animal behaviours, such as foraging or migration. However, few studies have investigated directly whether the presence of ALAN affects the ability to find a mate (mate location). One direct effect of the presence of ALAN is that it can create a light barrier in an otherwise dark environment. This may have significant behavioural implications for nocturnally active species if it affects their ability to respond to potential mates. Our study, using the acoustically orienting Australian black field cricket, Teleogryllus commodus, determined experimentally whether the presence of a fragmented light environment influenced movement patterns of virgin females and males. Moreover, given the importance of male song for reproductive outcomes in this species, we assessed simultaneously whether such behaviours were modified by the presence of a male attraction call. We found that while initiation of movement was slower in the presence of ALAN, the behavioural shifts associated with its presence were relatively small compared to the influence of a broadcast male attraction call. The response to the male attraction call was typically stronger for females than for males, but both males and females modified aspects of behaviour when it was present regardless of whether their immediate environment was fragmented by artificial light at night or not. Artificial light at night may alter subtle aspects of movement and mating behaviour in this species, but ultimately does not provide a barrier to movement or mate location.

}, keywords = {Insect, light pollution, mating, phonotaxis, reproduction}, doi = {10.1016/j.anbehav.2019.10.016}, url = {https://linkinghub.elsevier.com/retrieve/pii/S0003347219303483}, author = {Thompson, Eliza K. and Cullinan, Naomi L. and Jones, Ther{\'e}sa M. and Hopkins, Gareth R.} } @article {57603, title = {Experience modulates an insect{\textquoteright}s response to anthropogenic noise}, year = {2019}, abstract = {

In response to anthropogenic noise, vertebrates express modified acoustic communication signals either through individual plasticity or local population adaptation. In contrast, how insects respond to this stressor is poorly studied. Field crickets Gryllus bimaculatus use acoustic signals to attract and locate mates and are commonly found in noisy roadside environments, offering a powerful system to study the effects of anthropogenic noise on insect communication. Rapid repetition of sexual calls (chirps) is essential to attract females, but calling incurs energetic costs and attracts predators. As a result, males are predicted to reduce calling rates when background noise is high. Here, we combine observations and experimental playbacks to show that the responses of field cricket males to anthropogenic noise also depend on their previous experience with passing cars. First, we show that males living on highway edges decrease their chirp rate in response to passing cars. To assess whether this behavioral response depends on previous exposure to car noise, we then broadcast recordings of car noise to males located at different distances from the road and, therefore, with different previous exposure to car noise. Although all tested individuals responded to broadcasted traffic noise, males closest to the road decreased their chirp rate less than individuals calling further from the road. These results suggest that regular exposure to anthropogenic noise may decrease individuals\’ sensitivity and behavioral responses to noise, allowing them to maintain effective signaling rates. Behavioral plasticity modulated by experience may thus allow some insect species to cope with human-induced environmental stressors.

}, keywords = {acoustic adaptation, anthropogenic noise, behavioral plasticity, Gryllus bimaculatus, Insect, sexual signals}, doi = {10.1093/beheco/arz159}, url = {https://academic.oup.com/beheco/advance-article/doi/10.1093/beheco/arz159/5574703}, author = {Gallego-Abenza, Mario and Mathevon, Nicolas and Wheatcroft, David}, editor = {Candolin, Ulrika} } @article {57384, title = {Bark beetles use a spring-loaded mechanism to produce variable song patterns}, year = {2019}, abstract = {

Many insects vary their song patterns to communicate different messages, but the underlying biomechanisms are often poorly understood. Here, we report on the mechanics of sound production and variation in an elytro-tergal stridulator, male Dendroctonus valens bark beetles. Using ablation experiments coupled with high-speed video and audio recordings, we show that: (1) chirps are produced using a stridulatory file on the left elytron (forewing) and a protrusion (plectrum) on the seventh abdominal segment; (2) chirps are produced by \‘spring stridulation\’, a catch-and-release mechanism whereby the plectrum catches on a file tooth and, upon release, springs forward along the file; and (3) variability in chirp types is caused by introducing multiple catch-and-release events along the file to create regular interruptions. These results provide experimental evidence for the mechanics of elytro-tergal stridulation, and provide insight into how an insect can incorporate variability into its acoustic repertoire using a spring-loaded mechanism.

}, keywords = {Acoustic, communication, Dendroctonus valens, Insect, sound, stridulation}, doi = {10.1242/jeb.190660}, url = {http://jeb.biologists.org/lookup/doi/10.1242/jeb.190660}, author = {Lindeman, Amanda A. and Yack, Jayne E.} }