@article {58375, title = {Traps for Collecting Live Euphasiopteryx depleta (Diptera: Tachinidae) at a Sound Source}, year = {1988}, doi = {10.2307/3495023}, url = {https://www.jstor.org/stable/3495023?origin=crossref}, author = {Fowler, H. G.} } @article {58373, title = {Temporal patterns of parasitoid fly ( Ormia ochracea) attraction to field cricket song ( Gryllus integer)}, year = {1996}, abstract = {

Female flies, Ormia ochracea (Diptera, Tachinidae), orient to the calling song of the field cricket Gryllus integer (Orthoptera, Gryllidae) and deposit larvae that burrow into and consume the cricket host. Selection pressure from O. ochracea has probably been important in the evolution of male cricket songs and mating behaviour in G. integer and other cricket species. Tape-recorded G. integer calling song was broadcast to study the temporal rate of attraction of O. ochracea. Flies became phonotactic to cricket song approximately at sunset, and the highest level of attraction was observed in the following hours of the evening. Fly phonotaxis decreased in the hours immediately preceding sunrise and no flies were attracted during daylight hours. More male G. integer call at sunrise and in the preceding hours than earlier in the evening, perhaps in response to the lower probability of attracting O. ochracea.

}, doi = {10.1139/z96-046}, url = {http://www.nrcresearchpress.com/doi/10.1139/z96-046}, author = {Cade, William H. and Ciceran, Mark and Murray, Anne-Marie} } @article {57634, title = {The ability of the parasitoid fly Ormia ochracea to distinguish sounds in the vertical plane}, year = {2006}, abstract = {

The parasitic fly Ormia ochracea localizes its host, field crickets, by homing in on their calling song. Previous phonotactic studies indicate that their sound localization ability in azimuth is extraordinarily acute, but the fly\’s ability to localize the elevation of sound sources has not been tested to date. Here we show that in a freely-walking closed-loop Y-maze task elevational performance is well above chance, but slightly below the fly\’s performance in azimuth. Immobilizing the head or the halteres (sensory organs of balance) slightly lowered elevational discrimination, but performance was still well above chance. Because ormiine ears are thought to be symmetric and the pure-tone models of a cricket\’s call used in these experiments contained little to no spectral bandwidth, additional studies will be needed to elucidate the underlying cues. Nonetheless, it is clear that while walking, Ormia flies are capable of distinguishing sound sources that differ only in elevation.

}, doi = {10.1121/1.2225936}, url = {http://asa.scitation.org/doi/10.1121/1.2225936}, author = {Arthur, Ben J. and Ronald R. Hoy} } @article {57617, title = {The start of phonotactic walking in the fly Ormia ochracea: a kinematic study}, year = {2005}, abstract = {

Ormia ochracea (Diptera, Tachinidae) are acoustic parasitoids of crickets that have one of the most directionally sensitive auditory systems known. We studied dynamic characteristics of walking phonotaxis in these flies in response to variations in sound source azimuth, and compared phonotaxis of flies in freely walking conditions to tethered flies walking on a treadmill. Motor patterns at the initiation of phonotaxis are not stereotyped even for similar stimulus conditions. Flies respond to directional sound sources by walking in a tight curve that combines rotation and forward translation until they are oriented towards the source direction, then continue on a straight path. Translational velocity accelerates throughout the duration of the stimulus then decelerates following stimulus offset. In contrast, rotational velocity accelerates and then decelerates within the duration of the stimulus such that flies have completed the rotational component of the response and reached\ their final heading before the end of the stimulus. Rotational velocity is the only response parameter that varies systematically with sound source direction (azimuth). Differences in the amplitude of rotational velocity as a function of source azimuth determine the directional orientation of phonotactic responses. The relationship between rotational velocity and source azimuth is similar to a neural measure of auditory directionality (interaural latency). There were some differences between freely walking and tethered conditions, although both showed qualitatively similar responses. Flies accelerated more slowly and attained lower maximum velocities on the treadmill, consistent with the greater inertia of the treadmill sphere relative to the flies. Also, flies tended to continue walking longer on the treadmill following cessation of the stimulus.

}, doi = {10.1242/jeb.01926}, url = {http://jeb.biologists.org/cgi/doi/10.1242/jeb.01926}, author = {Mason, A. C. and Norman Lee and Oshinsky, Michael L.} } @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 {52759, title = {The evolutionary convergence of hearing in a parasitoid fly and its cricket host}, journal = {Science}, volume = {258}, year = {1992}, month = {Jan-11-1993}, pages = {1135 - 1137}, abstract = {

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\&$\#$39;s ear than a typical fly\&$\#$39;s ear, allowing these parasitoids to take advantage of the sensory ecological niche of their host.

}, issn = {0036-8075}, doi = {10.1126/science.1439820}, url = {http://www.sciencemag.org/cgi/doi/10.1126/science.1439820https://syndication.highwire.org/content/doi/10.1126/science.1439820}, author = {Daniel Robert and Amoroso, J and Ronald R. Hoy} } @article {52758, title = {Acoustically Orienting Parasitoids: Fly Phonotaxis to Cricket Song}, journal = {Science}, volume = {190}, year = {1975}, month = {Feb-12-1977}, pages = {1312 - 1313}, issn = {0036-8075}, doi = {10.1126/science.190.4221.1312}, url = {http://www.sciencemag.org/cgi/doi/10.1126/science.190.4221.1312https://syndication.highwire.org/content/doi/10.1126/science.190.4221.1312}, author = {William H. Cade} } @article {52754, title = {Convergent song preferences between female field crickets and acoustically orienting parasitoid flies}, journal = {Behavioral Ecology}, volume = {7}, year = {1996}, month = {Jan-01-1996}, pages = {279 - 285}, abstract = {

Traits that increase the attractiveness of males to females often make them more conspicuous to predators. In the field cricket (Gryllus lineaticeps), males are attacked by parasitoid tachinid flies (Ormia ochracea) that locate males through their calls. Female flies larviposit on crickets and the larvae burrow into and feed on the cricket, killing the cricket upon emergence. To determine whether traits preferred by females increase a male\&$\#$39;s risk of attracting a predator, I examined the effect of variation in male singing behavior on mate and predator attraction. Both female crickets and female flies preferred male calling songs with higher chirp rates, longer chirp durations, and higher chirp amplitudes. In addition, both female crickets and female flies preferred male calling songs with higher chirp rates and longer chirp durations, even when these songs were of lower amplitude. These results suggest that sexual selection by female choice will favor the evolution of higher chirp rates and longer chirp durations. However, call types that increase a male\&$\#$39;s attractiveness to females also appear to increase a male\&$\#$39;s risk of attracting parasitoids. Sexual and natural selection appear to have opposing effects on the evolution of male singing behavior in this species.

}, issn = {1045-2249}, doi = {10.1093/beheco/7.3.279}, url = {https://academic.oup.com/beheco/article-lookup/doi/10.1093/beheco/7.3.279}, author = {William E. Wagner} } @article {47912, title = {Female Field Crickets Incur Increased Parasitism Risk When Near Preferred Song}, journal = {PLoS ONE}, volume = {5}, year = {2010}, month = {Sep-03-2010}, pages = {e9592}, abstract = {

Female animals often prefer males with conspicuous traits because these males provide direct or indirect benefits. Conspicuous male traits, however, can attract predators. This not only increases the risk of predation for conspicuous males but also for the females that prefer them. In the variable field cricket, Gryllus lineaticeps, males that produce preferred song types provide females with greater material benefits, but they are also more likely to attract lethal parasitoid flies. First, we conducted a field experiment that tested the hypothesis that females have a greater risk of fly parasitism when in association with preferred high chirp rate males. Females were nearly twice as likely to be parasitized when caged with high chirp rate song than when caged with low chirp rate song. Females may thus be forced to trade off the quality of the benefits they receive from mating with preferred males and the risk of being killed by a predator when near these males. Second, we assessed female parasitism rates in a natural population. Up to 6\% of the females were parasitized in field samples. Because the females we collected could have become parasitized had they not been collected, this provides a minimum estimate of the female parasitism rate in the field. In a laboratory study, we found no difference in the proportion of time parasitized and unparasitized females spent hiding under shelters; thus, differences in activity patterns do not appear to have biased our estimate of female parasitism rates. Overall, our results suggest that female association costs have the potential to shape the evolution of female mating preferences.

}, doi = {10.1371/journal.pone.000959210.1371/journal.pone.0009592.g00110.1371/journal.pone.0009592.g002}, url = {http://dx.plos.org/10.1371/journal.pone.0009592}, author = {Martin, Cassandra M. and William E. Wagner} } @article {47908, title = {Behavioural specialization among populations of the acoustically orienting parasitoid fly Ormia ochracea utilizing different cricket species as hosts}, journal = {Animal Behaviour}, volume = {73}, year = {2007}, month = {Jan-01-2007}, pages = {99 - 104}, abstract = {

Tightly coupled evolutionary associations between parasites and their hosts are well known. What is less well characterized is the behavioural specialization of parasites that exploit different hosts in different parts of the parasite\’s geographical range. Here we examine behavioural specialization among populations of a parasitoid fly, Ormia ochracea, that exploit different host species of crickets in different parts of the fly\’s range. We conducted a field experiment to compare phonotactic attraction of flies from Florida, Texas, California and Hawaii (U.S.A.) to the songs of their local host species of cricket versus their attraction to the songs of species of crickets utilized as hosts elsewhere within the flies\’ range. We found strong behavioural specialization of fly populations, with preferential phonotaxis towards the song of the local host species of cricket. These results suggest strong behavioural specialization of flies, but that specialization does not constrain or preclude the rapid adoption of novel hosts.

}, keywords = {acoustic communication, behavioural specialization, diptera-orthoptera coevolution, eavesdropping, host selection, Ormia ochracea, parasitoid fly}, issn = {00033472}, doi = {10.1016/j.anbehav.2006.07.005}, url = {http://linkinghub.elsevier.com/retrieve/pii/S0003347206003939}, author = {Gray, David A. and Banuelos, Christina and Sean E. Walker and William H. Cade and Zuk, Marlene} } @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.} }