02220nas a2200181   4500008004100000245009000041210006900131520162800200653001301828653001801841653001201859653002301871653001501894653002001909100001701929700002401946856006801970       2005                        eng d00aEffect of the Temporal Pattern of Contralateral Inhibition on Sound Localization Cues0 aEffect of the Temporal Pattern of Contralateral Inhibition on So3 a<p>We studied the temporal coding properties of identified interneurons in the auditory system of crickets, using information theory as an analytical tool. The ascending neuron 1 (AN1), which is tuned to the dominant carrier frequency (CF) of cricket songs, selectively codes the limited range of amplitude modulation (AM) frequencies that occur in these signals. AN2, which is most sensitive to the ultrasonic frequencies that occur in echolocation calls of insectivorous bats, codes a broader range of AM frequencies, as occur in bat calls. A third neuron, omega neuron 1 (ON1), which is dually tuned to both ranges of carrier frequency, was shown previously to have CF-specific coding properties, allowing it to represent accurately the differing temporal structures of both cricket songs and bat calls. ON1 is a source of contralateral inhibition to AN1 and AN2, enhancing binaural contrast and facilitating sound localization. We used dichotic stimulation to examine the importance of the temporal structure of contralateral inhibition for enhancing binaural contrast. Contralateral inhibition degrades the coding of temporal pattern by AN1 and AN2, but only if the temporal pattern of inhibitory input matches that of excitation. Firing rate is also decreased most strongly by temporally matched contralateral inhibition. This is apparent for AN1 in its mean firing rate; for AN2, high-frequency firing is selectively suppressed. Our results show that the CF-specific coding properties of ON1 allow this single neuron to enhance effectively localization cues for both cricket-like and bat-like acoustic signals.</p>
10aauditory10acommunication10acricket10ainformation theory10aphonotaxis10atemporal coding1 aMarsat, Gary1 aPollack, Gerald, S.  uhttp://www.jneurosci.org/cgi/doi/10.1523/JNEUROSCI.0646-05.200502397nas a2200205   4500008004100000022001400041245010100055210006900156260001600225300001400241490000800255520172600263653002101989653002302010653001802033653001502051100002702066700002102093856007702114       2005                        eng d  a0005-795900aAlternate tactics in male bladder grasshoppers Bullacris membracioides (Orthoptera: Pneumoridae)0 aAlternate tactics in male bladder grasshoppers Bullacris membrac  cJan-06-2005  a761 - 7780 v1423 a<p>Bladder grasshoppers (Orthoptera, Pneumoridae) are a unique group of nocturnal, specialized herbivores, endemic to coastal regions of Southern Africa. Adult males are characterized by an inflated abdomen, which develops at the final molt, and a signaling system capable of producing high intensity calls detectable by conspecifics at distances of up to 2 km. Female response to male calls leads to reciprocal duetting and pair formation. We have found an alternative form to the dominant inflated male tactic in three pneumorid species. These alternate males are incapable of flight and lack the air-filled abdominal bladder used in long-range acoustic communication; but may be found in copula with mature females in the field. Here we address the issue of neoteny/paedogenesis in the alternate male by comparing the morphology of inflated and uninflated adult male Bullacris membracioides with that of ultimate and penultimate nymphal instars, to determine whether these forms follow a common developmental trajectory. We then compare the behavioral responsiveness of inflated and noninflated morphs to conspecific advertisement calls, to ascertain whether alternate males have the potential to actively exploit the mate location system of duetting pairs. Morphometric analyses indicate that alternate males are a distinctly divergent form from the primary male developmental tactic. We conclude that males following the alternate tactic eavesdrop on the duets of inflated males and females to exploit the acoustic mate location system. This satellite tactic has potential impact on several aspects of pneumorid biology contributing to biasing sexual selection, sensory drive, and ultimately speciation events.</p>
10aalternative male10abehavioral tactics10acommunication10amorphology1 avan Staaden, Moira, J.1 aDonelson, Nathan  uhttp://booksandjournals.brillonline.com/content/10.1163/156853905472908802265nas a2200169   4500008004100000245015200041210006900193300001200262490000700274520167200281653001801953653001501971653002001986653002402006100002302030856004202053       2004                        eng d00aReproductive Behavior of Ground Weta (Orthoptera: Anostostomatidae): Drumming Behavior, Nuptial Feeding, Post-copulatory Guarding and Maternal Care0 aReproductive Behavior of Ground Weta Orthoptera Anostostomatidae  a414-4280 v773 a<p>Compared to other ensiferan Orthoptera such as true crickets (Gryllidae) and katydids (Tettigoniidae) relatively little is known about the reproductive behavior of Anostostomatidae (formerly Stenopelmatidae), the king crickets, weta and allies. Moreover, although the New Zealand species (the weta) are best known, there is little knowledge of the biology of ground weta (Hemiandrus species), a variable genus especially with regard to ovipositor length. This paper presents observations of mating and post-mating behavior of several Hemiandrus species with short ovipositors. Sexually active males and females drum their abdomens on the substrate, apparently as local signals for mate attraction (pheromones may be involved in long distance communication). After mating there is both maternal and paternal investment. Females provide care to eggs and young larvae and males provide a spermatophylax to the female, a mating meal that, in other ensiferan Orthoptera can be an important source of nutrition. In contrast to other ensiferans, however, the spermatophylax of Hemiandrus species with short ovipositors is deposited on the female&rsquo;s abdomen, a separate location from the sperm ampulla. The spermatophylax is deposited while the male is attached to the female&rsquo;s underside, apparently to her modified 6th abdominal sternite. Also, in contrast to related taxa, males remain with their mates while the mating meal is eaten. These observations indicate that ground weta are excellent systems for examining behavioral and ecological questions about the evolution of complex signals, as well as the evolution of maternal and paternal investment.</p>
10acommunication10aHemiandrus10amating behavior10aparental investment1 aGwynne, Darryl, T.  uhttp://www.jstor.org/stable/25086232 