01440nas a2200133 4500008004100000245011900041210006900160300001200229490000800241520097300249100002201222700002101244856004101265 1996 eng d00aSound production and cannibalism in larvae of the pine-sawyer beetle Monochamus sutor L.(Coleoptera: Cerambycidae)0 aSound production and cannibalism in larvae of the pinesawyer bee a29–330 v1173 a

One-year old larvae of the pine-sawyer beetle, Monochamus sutor L. (Coleoptera: Ceram­ bycidae), produced regular, chirping sounds, easily heard up to 10 meters away. Larvae were positioned within their hibernation tunnel in sapwood of recently fire-killed spruce and pine trees. Their heads were directed outwards, and the sound was probably produced by the scratching of their mandibles against the bark. Since the larvae produce this sound in spite of the risk of attracting parasites and predators such as wood-peckers, this behaviour most likely has an adaptive value. We suggest that sound production helps a larva to secure resources around its hibernation tunnel for its own development by keeping away other potentially competitive larvae. That the larvae are cannibalistic was demonstrated during a trial perfor­ med in petri dishes filled with sawdust. Any larva ignoring the sound signal could therefore face a real threat of being killed.

1 aVictorsson, Jonas1 aWikars, Lars-Ove uhttps://bio.acousti.ca/it/node/4771301757nas a2200121 4500008004100000245003800041210003800079300001000117490000800127520143900135100002001574856004101594 1981 eng d00aUltraljud hos svenska vårtbitare0 aUltraljud hos svenska vårtbitare a27-410 v1023 a

Of the 10 Swedish species of bush crickets 9 stridulate with their elytra. The author recorded the songs of these species in their natural habitats, using instrumentation tape recorder and ultrasonic detectors. Song rhythm patterms and frequencies are presented for each species with comments on the ultrasonic components, audibility as a distance in the field with and without detectors etc. For 8 of the 9 stridulating species detectors seem to be necessary for efficient survey work and population studies in the field.

In 5 species differences found between the songs used in daytime and at night were analysed and discussed. The most important differences were found in species singing close to the ground (Platycleis denticulata, Metrioptera brachyptera, M. bicolor), whereas no corresponding difference was found in species singing from trees or high busghes (Tettigonia viridissima, Leptophyes punctatissima). The very intense songs heard at night have distinct and discrete tooth-pulses, while corresponding songs in daytime contain continuous sound waves and less conspicuous tooth-pulses in the file pulse-train. It is suggested taht this phenomenon could be something more than a mere influence of temperature on song rhythym. They could be adaptations to more efficient spread of sound waves under the acoustical conditions taht prevail above ground at night.

1 aAhlén, Ingemar uhttps://bio.acousti.ca/it/node/17245