01293nas a2200169 4500008004100000022001400041245008500055210006900140260001600209300001600225490000800241520069000249100001900939700001500958700002000973856013000993 1992 eng d a0036-807500aThe evolutionary convergence of hearing in a parasitoid fly and its cricket host0 aevolutionary convergence of hearing in a parasitoid fly and its  cJan-11-1993 a1135 - 11370 v2583 a

Parasitism is a widespread and diverse life strategy that connects species throughout the animal kingdom. Female parasitoid flies of the genus Ormia must find a specific cricket host on which to deposit their parasitic maggots. To reproduce, female flies must perform the same task as female crickets: find a singing male cricket. These flies have evolved a unique hearing organ that allows them to detect and locate singing male crickets. Through evolutionary convergence, these flies possess a hearing organ that much more resembles a cricket's ear than a typical fly's ear, allowing these parasitoids to take advantage of the sensory ecological niche of their host.

1 aRobert, Daniel1 aAmoroso, J1 aHoy, Ronald, R. uhttp://www.sciencemag.org/cgi/doi/10.1126/science.1439820https://syndication.highwire.org/content/doi/10.1126/science.143982000999nas a2200121 4500008004100000245008500041210006900126300001000195490000700205520060300212100002100815856004100836 1992 eng d00aEffects of temperature on chirp rates of tree crickets (Orthoptera: Oecanthidae)0 aEffects of temperature on chirp rates of tree crickets Orthopter a70-730 v273 a

The relationship between temperature and chirp rate is described for three African tree crickets, Oecanthus capensis, O. karschi and O. sycomorus. Knowledge of the variation in chirp rates of O. karschi and O. capensis makes it possible to discriminate between the songs of these species with a stopwatch. Their songs can also be used to estimate air temperature. When signals like cricket songs change with temperature, the response may also be affected. Some problems associated with temperature dependant communication systems are discussed.

1 aToms, Robert, B. uhttps://bio.acousti.ca/fi/node/4788101261nas a2200157 4500008004100000022001300041245006800054210006400122260001600186300001400202490000700216520077200223100002200995700002001017856006601037 1992 eng d a0003347200aThe quantitative genetics of sound production in Gryllus firmus0 aquantitative genetics of sound production in Gryllus firmus cJan-11-1992 a823 - 8320 v443 a

The species-specific calling songs of male cricket are used by females for species recognition and mate choice. Heritability of variation of morphological structures involved in song production, components of the calling song, and body size were estimated for the cricket Gryllus firmus. The heritabilities of morphological structures range from 0·42 to 0·73, while those of the song components range from 0·10 to 0·35. Comparison between sire and dam components suggests that there may be non-additive and/or maternal effects. As a result of the low correlation between body size and song components, it is unlikely that female G. firmus use the calling song to assess male body size or wing morph (micropterous or macropterous).

1 aWebb, Karen, Lynn1 aRoff, Derek, A. uhttp://linkinghub.elsevier.com/retrieve/pii/S000334720580578001289nas a2200157 4500008004100000022001300041245014200054210006900196260001600265300001600281490000700297520072100304100002301025700001701048856006601065 1992 eng d a0003347200aVariability in call structure and pairing success of male field crickets, Gryllus bimaculatus: the effects of age, size and parasite load0 aVariability in call structure and pairing success of male field  cJan-12-1992 a1145 - 11520 v443 a

The effects of male body size, age and gregarine parasite load on the structure of calls and success at attracting mates were investigated in a natural population of the field cricket, Gryllus bimaculatus. The syllable rate within chirps was negatively related to male size, and the duration of syllables was positively related to size. Older males had more variable syllable rates within their chirps. Size did not influence pairing success. However, paired males were significantly older than solitary calling males. Parasitic infection influenced the pairing success of young males but not old males. These data are discussed in the context of direct and indirect selection for female mating preferences.

1 aSimmons, Leigh, W.1 aZuk, Marlene uhttp://linkinghub.elsevier.com/retrieve/pii/S000334720580326402759nas a2200133 4500008004100000245006000041210005800101300001200159490000800171520236000179100002502539700001302564856004802577 1992 eng d00aA MODEL OF THE MECHANISM OF SOUND PRODUCTION IN CICADAS0 aMODEL OF THE MECHANISM OF SOUND PRODUCTION IN CICADAS a123-1530 v1733 a

1. Dried cicada bodies of the species Cyclochila australasiae and model cicadas made from a miniature earphone driving a plastic cavity were used to study the acoustics of sound production in male cicadas.

2. A model cicada with shape and dimensions similar to those of the abdomen of a male C. australasiae resonates at the natural song frequency of the species (4.3 kHz). The abdominal air sac of C. australasiae also resonates at frequencies close to the natural song frequency when excited by external sounds. In an atmosphere of chlorofluorocarbon (CFC) gas, the resonant frequency is lowered in keeping with the decrease in velocity of sound in the CFC gas.

3. At the model's resonant frequency, the driving earphone dissipates more electrical power with the cavity attached than without the cavity. The cavity of the model cicada acts as a narrow-band acoustic acceptance filter, tuned to the natural song frequency.

4. When the miniature earphone emits brief clicks, mimicking those produced by the natural tymbal mechanism, the model cicada produces sound pulses that vary in duration and shape according to the number and timing of the clicks. A coherent train of two or three resonant clicks results in a long slowly-decaying sound pulse similar to that in the natural song.

5. The natural song frequency can be predicted from the dimensions of the abdominal cavity and the tympana in C. australasiae using a simple equation for the resonant frequency of a Helmholtz resonator. This equation also predicts the song frequency of Macrotristria angularis and Magicicada cassini, but it fails with the low-frequency song of Magicicada septendecim. This discrepancy can be accounted for by the unusually thick tympana of M. septendecim, which tend to lower the resonant frequency of the system.

6. We conclude that the abdomen of male cicadas forms a Helmholtz resonator, the components of which are the large air sac as the cavity and the tympana as the neck of the resonator. We suggest that cicada sound production depends on the coupling of two resonators, that of the tymbal and that of the abdominal air sac, from which sound is radiated through the tympana. The coupled resonator system would produce the long sound pulses required for stimulating a sensitive sharply tuned auditory organ.

1 aBennet-Clark, H., C.1 aYoung, D uhttp://jeb.biologists.org/content/173/1/123