@article {57601, title = {Auditory Sensitivity of an Acoustic Parasitoid (Emblemasoma sp., Sarcophagidae, Diptera) and the Calling Behavior of Potential Hosts}, journal = {Brain, Behavior and Evolution}, volume = {72}, year = {2008}, month = {Jan-01-2008}, pages = {16 - 26}, abstract = {

Using field broadcasts of model male calling songs, we tested whether Tibicen pruinosa and T. chloromera (Homoptera: Cicadidae) are candidate hosts for acoustic parasitoid flies. The model calling song of T. pruinosa attracted 90\% of the flies (Sarcophagidae: Emblemasoma sp.; all larvapositing females) when broadcast simultaneously with the model T. chloromera song, a phonotactic bias reconfirmed in single song playbacks. In paired broadcasts of model T. pruinosa songs with different relative amplitudes (3 dB or 6 dB), significantly more flies were attracted to the more powerful song, a result consistent with the responses predicted by a model proposed by Forrest and Raspet [1994]. Using intracellular recordings and dye injections, we characterized the sensitivity of auditory units in sound-trapped flies. Intracellular recordings from six auditory units (5 interneurons, 1 afferent) revealed best sensitivity for frequencies near 3-4 kHz, matching the predominant spectral components of the calling songs of both species of cicada. Interestingly, although flies could be attracted to T. pruinosa broadcasts throughout the day, hourly censuses of singing males revealed that calling occurred exclusively at dusk. Furthermore, the duration of the dusk chorus in T. pruinosa was significantly shorter than the midday chorus of the less attractive song of T. chloromera. We propose that the tight temporal aggregation of the dusk chorus time could function to reduce risk from attracted parasitoids.

}, keywords = {Chorus, Cicada, cricket, Diel Behavior, Emblemasoma, frequency tuning, interneuron, Ormia, parasitoid, phonotaxis, Tibicen}, issn = {0006-8977}, doi = {10.1159/000139458}, url = {https://www.karger.com/Article/FullText/139458}, author = {Farris, H.E. and Oshinsky, M.L. and Forrest, T.G. and Ronald R. Hoy} } @article {57403, title = {Physiology of the Auditory Afferents in an Acoustic Parasitoid Fly}, year = {2002}, abstract = {

The fly, Ormia ochracea, possess a novel auditory organ, which allows it to detect airborne sounds. The mechanical coupling of its pair of tympanal membranes provides the basis for a unique means of sensing the direction of a sound source. In this study, we characterized the neuroanatomy, frequency tuning, and neurophysiological response properties of the acoustic afferents. Our experiments demonstrate that the fly\&$\#$39;s nervous system is able to encode and localize the direction of a sound source, although the binaural auditory cues available in the acoustic sound field are miniscule. Almost all of the acoustic afferents recorded in this study responded to short and long sound pulses with a phasic burst of one to four action potentials. A few afferents responded tonically for the duration of the sound stimulus. A prominent class of afferents responds to suprathreshold stimuli with only a single spike discharge, independent of stimulus level, frequency, or duration. We also tested the response of the afferents to speakers separated by 180\° along the azimuth of the fly. We found that the afferent responses have a shorter latency because of ipsilateral stimulation. This could be a temporal code of the direction of a sound source. The threshold frequency tuning for the afferents revealed a range of sensitivities to the frequency of the cricket host\&$\#$39;s calling song frequency. The difference in the number of afferents above threshold on either side of the animal is a population code, which can also be used for sound localization.

}, keywords = {arthropod, directional hearing, mechanical coupling, parasitoid, population coding, time coding}, doi = {10.1523/JNEUROSCI.22-16-07254.2002}, url = {http://www.jneurosci.org/lookup/doi/10.1523/JNEUROSCI.22-16-07254.2002https://syndication.highwire.org/content/doi/10.1523/JNEUROSCI.22-16-07254.2002}, author = {Oshinsky, Michael L.} } @article {47781, title = {Host song selection by an acoustically orienting parasitoid fly exploiting a multispecies assemblage of cricket hosts}, journal = {Animal Behaviour}, volume = {81}, year = {2011}, month = {Jan-04-2011}, pages = {851 - 858}, abstract = {

Specialization by predators, parasites and parasitoids is often viewed as adaptive because specialization will usually increase search efficiency for suitable hosts (prey). Although many studies have documented interspecific variation in the degree of host specialization, few studies have examined intraspecific variation in specialization among different populations exploiting different numbers of hosts, and even fewer have specifically examined variation in behavioural specialization. Here we examine the acoustic preferences of a parasitoid fly, Ormia ochracea, which attacks several Gryllus species of field crickets by using the male cricket song to locate hosts. All previous studies with this system have examined fly song preferences in populations of flies that primarily exploit a single host species of cricket. Here we tested a population of flies that naturally parasitizes multiple cricket species. We found significant interspecific host song preferences; however, as predicted, the strength of preference was reduced compared to single-host populations of flies. We also examined fly song selection for intraspecific variants of two of the cricket host species; flies showed significant preference for intraspecific song variants of one of the two cricket species. Our results demonstrate that the degree of behavioural specialization, in a very highly specialized fly, nevertheless shows interpopulation variation consistent with the numbers of host species utilized.

}, keywords = {Gryllus, Ormia ochracea, parasitoid, specialization, variation}, issn = {00033472}, doi = {10.1016/j.anbehav.2011.01.024}, url = {http://linkinghub.elsevier.com/retrieve/pii/S0003347211000273}, author = {Sakaguchi, Kelly M. and Gray, David A.} }