02317nas a2200193 4500008004100000245011500041210006900156520166100225653001101886653002001897653001101917653001501928653001701943100002401960700002401984700002402008700002402032856006702056 2019 eng d00aEffects of artificial light at night and male calling on movement patterns and mate location in field crickets0 aEffects of artificial light at night and male calling on movemen3 a

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.

10aInsect10alight pollution10amating10aphonotaxis10areproduction1 aThompson, Eliza, K.1 aCullinan, Naomi, L.1 aJones, Therésa, M.1 aHopkins, Gareth, R. uhttps://linkinghub.elsevier.com/retrieve/pii/S000334721930348302446nas a2200205 4500008004100000245007100041210006900112520175400181653002401935653002401959653002601983653002402009653001102033653001902044100002602063700002202089700002202111700002102133856008602154 2019 eng d00aExperience modulates an insect’s response to anthropogenic noise0 aExperience modulates an insect s response to anthropogenic noise3 a

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.

10aacoustic adaptation10aanthropogenic noise10abehavioral plasticity10aGryllus bimaculatus10aInsect10asexual signals1 aGallego-Abenza, Mario1 aMathevon, Nicolas1 aWheatcroft, David1 aCandolin, Ulrika uhttps://academic.oup.com/beheco/advance-article/doi/10.1093/beheco/arz159/557470301646nas a2200181 4500008004100000245008100041210006900122520107500191653001301266653001801279653002401297653001101321653001001332653001701342100002501359700002001384856006001404 2019 eng d00aBark beetles use a spring-loaded mechanism to produce variable song patterns0 aBark beetles use a springloaded mechanism to produce variable so3 a

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.

10aAcoustic10acommunication10aDendroctonus valens10aInsect10asound10astridulation1 aLindeman, Amanda, A.1 aYack, Jayne, E. uhttp://jeb.biologists.org/lookup/doi/10.1242/jeb.190660