Versatile Aggressive Mimicry of Cicadas by an Australian Predatory Katydid

Background: In aggressive mimicry, a predator or parasite imitates a signal of another species in order to exploit the recipient of the signal. Some of the most remarkable examples of aggressive mimicry involve exploitation of a complex signal-response system by an unrelated predator species. Methodology/Principal Findings: We have found that predatory Chlorobalius leucoviridis katydids (Orthoptera: Tettigoniidae) can attract male cicadas (Hemiptera: Cicadidae) by imitating the species-specific wing-flick replies of sexually receptive female cicadas. This aggressive mimicry is accomplished both acoustically, with tegminal clicks, and visually, with synchronized body jerks. Remarkably, the katydids respond effectively to a variety of complex, species-specific Cicadettini songs, including songs of many cicada species that the predator has never encountered. Conclusions/Significance: We propose that the versatility of aggressive mimicry in C. leucoviridis is accomplished by exploiting general design elements common to the songs of many acoustically signaling insects that use duets in pairformation. Consideration of the mechanism of versatile mimicry in C. leucoviridis may illuminate processes driving the evolution of insect acoustic signals, which play a central role in reproductive isolation of populations and the formation of species

The Signaller's Dilemma: A Cost–Benefit Analysis of Public and Private Communication

Understanding the diversity of animal signals requires knowledge of factors which may influence the different stages of communication, from the production of a signal by the sender up to the detection, identification and final decision-making in the receiver. Yet, many studies on signalling systems focus exclusively on the sender, and often ignore the receiver side and the ecological conditions under which signals evolve.We study a neotropical katydid which uses airborne sound for long distance communication, but also an alternative form of private signalling through substrate vibration. We quantified the strength of predation by bats which eavesdrop on the airborne sound signal, by analysing insect remains at roosts of a bat family. Males do not arbitrarily use one or the other channel for communication, but spend more time with private signalling under full moon conditions, when the nocturnal rainforest favours predation by visually hunting predators. Measurements of metabolic CO(2)-production rate indicate that the energy necessary for signalling increases 3-fold in full moon nights when private signalling is favoured. The background noise level for the airborne sound channel can amount to 70 dB SPL, whereas it is low in the vibration channel in the low frequency range of the vibration signal. The active space of the airborne sound signal varies between 22 and 35 meters, contrasting with about 4 meters with the vibration signal transmitted on the insect's favourite roost plant. Signal perception was studied using neurophysiological methods under outdoor conditions, which is more reliable for the private mode of communication.Our results demonstrate the complex effects of ecological conditions, such as predation, nocturnal ambient light levels, and masking noise levels on the performance of receivers in detecting mating signals, and that the net advantage or disadvantage of a mode of communication strongly depends on these conditions

A revision of the South African katydid genus Austrodontura Fontana & Buzzetti (Orthoptera: Tettigoniidae: Phaneropterinae)

The South African genus Austrodontura Fontana & Buzzetti of brachypterous katydids is revised. A. capensis (Walker, 1869) is redescribed and A. castletoni sp. n. from the Eastern Cape Province is described, A. raggei Fontanta & Buzzetti is considered a junior synonym of A. capensis. Acoustic behavior of A. castletoni is described. Copyright © 2011 · Magnolia Press.Articl

A new genus and species of Mantophasmatidae (Insecta: Mantophasmatodea) from the Brandberg Massif, Namibia, with notes on behaviour.

A new genus and species of Mantophasmatidae, namely: Tyrannophasma gladiator ZOMPRO, gen. nov. sp. nov., is described and figured based on material from the Brandberg Massif, Omaruru District, Namibia. A key to fossil and extant genera of Mantophasmatodea and new observations on the bionomics and behaviour of T. gladiator sp. nov. and Mantophasma zephyra ZOMPRO ET AL., 2002, are included. ‘Gladiator-bugs’ is here proposed as the vernacular name for the order Mantophasmatodea. A standardised set of defined measurements for the description of species is proposed

Rôle de la charge de la sonde moléculaire sur la solvatation. Aspects statiques et dynamiques

Nous avons étudié la réorganisation du solvant autour de deux sondes moléculaires, le LDS 751 et le DCM en solution dans le méthanol. La diminution du nombre d'onde du barycentre du spectre de fluorescence du DCM en fonction du temps donne une cinétique bi-exponentielle; le déclin rapide a une constante de temps de (175 ± 100) fs et la composante lente (3,2 ± 0,1) ps est identique à celle trouvée dans le cas du LDS 751. Ces observations sont analysées en faisant référence à la distribution des charges dans les états électroniques impliqués et aux résultats de la littérature sur une autre sonde moléculaire, l'électron solvaté généré par radiolyse pulsée ou par ionisation multi-photonique du méthanol

An Old World leaf‐cutting, fungus‐growing ant: A case of convergent evolution

International audienceThe African myrmicine ant Crematogaster clariventris is a territorially dominant arboreal species that constructs very hard carton nests. Noting that workers cut off leaves from different plant species while building or repairing their nests, we asked ourselves if there was a correlation. We conducted scanning electron microscopic observations of nest walls that revealed the presence of fungal mycelia. As the presence of filamentous Ascomycota has been shown on arboreal ant nests worldwide, we used a metabarcoding approach and, indeed, noted the presence of Operational Taxonomi