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Heller K.-G.,Friedrich - Alexander - University, Erlangen - Nuremberg | Ostrowski T.D.,Johann Friedrich Blumenbach Institute | Hemp C.,University of Bayreuth
Bioacoustics | Year: 2010

The carrier frequency of the calling songs of bush-crickets (Tettigonioidea) is generally negatively correlated with body size; the smaller the species, the higher the frequency. However, in the correlation between body size and frequency there is a large variation. Some species do not seem to follow the main trend, but the reason(s) for the deviations from the negative correlation are largely unknown. Especially interesting are species which produce sounds "too" low for their size because this requires special and - judging from the other species - probably expensive modifications of the tegmina. Here we present data on the signal and the acoustic behaviour of Aerotegmina kilimandjarica, a small species with extraordinarily enlarged and inflated tegmina. The calling song has its peak frequency at 5 kHz (bandwidth 10 dB below peak 4-10 kHz). The species has a typical tettigoniid hearing curve, being most sensitive at 10 kHz (threshold 45 dB SPL). Taking into account the atmospheric attenuation, the song (loudness 100 dB SPL at 1 m) has a greater range at 5 kHz than at 10 kHz, so that maximising the range may have been one reason for the use of this unusually low frequency. © 2010 AB Academic Publishers. Source


Schmitt-Engel C.,Friedrich - Alexander - University, Erlangen - Nuremberg | Schmitt-Engel C.,Johann Friedrich Blumenbach Institute | Cerny A.C.,Friedrich - Alexander - University, Erlangen - Nuremberg | Cerny A.C.,University of Hohenheim | Schoppmeier M.,Friedrich - Alexander - University, Erlangen - Nuremberg
Developmental Biology | Year: 2012

Abdominal patterning in Drosophila requires the function of Nanos (nos) and Pumilio (pum) to repress posterior translation of hunchback mRNA. Here we provide the first functional analysis of nanos and pumilio genes during blastodermal patterning of a short-germ insect. We found that nos and pum in the red flour beetle Tribolium castaneum crucially contribute to posterior segmentation by preventing hunchback translation. While this function seems to be conserved among insects, we provide evidence that Nos and Pum may also act on giant expression, another gap gene. After depletion of nos and pum by parental RNAi, Hunchback and giant remain ectopically at the posterior blastoderm and the posterior Krüppel (Kr) domain is not being activated. giant may be a direct target of Nanos and Pumilio in Tribolium and presumably prevents early Kr expression. In the absence of Kr, the majority of secondary gap gene domains fail to be activated, and abdominal segmentation is terminated prematurely. Surprisingly, we found Nos and Pum also to be involved in early head patterning, as the loss of Nos and Pum results in deletions and transformations of gnathal and pre-gnathal anlagen. Since the targets of Nos and Pum in head development remain to be identified, we propose that anterior patterning in Tribolium may involve additional maternal factors. © 2012 Elsevier Inc. Source


Vedenina V.,Russian Academy of Sciences | Fahsing S.,Johann Friedrich Blumenbach Institute | Sradnick J.,Johann Friedrich Blumenbach Institute | Sradnick J.,TU Dresden | And 2 more authors.
Biological Journal of the Linnean Society | Year: 2013

Two grasshopper species, Stenobothrus rubicundus and Stenobothrus clavatus, were previously shown to hybridize in a narrow contact zone on Mount Tomaros in northern Greece. The species are characterized by complex and completely different courtship songs. In the present study, we investigated female preferences for the courtship songs of S.rubicundus, S.clavatus and hybrids in playback experiments. Playback of the courtship songs revealed assortative preferences in females of the parental species: they significantly more often preferred the songs of conspecific males. Hybrid females showed a lower selectivity than parental females, responding somewhat equally eager to playback of the songs of S.clavatus, S.rubicundus, and natural hybrid song, although less actively to the F1 hybrid song. The results suggest that hybrid males may lose to males of parental species, whereas hybrid females would even have an advantage over parental females. Comparison of responses of females from allopatric populations and Mount Tomaros to different song types shows no evidence for reinforcement. Asymmetry found in female preferences may have implications for the structure of the hybrid zone. © 2013 The Linnean Society of London. Source


Vedenina V.,Russian Academy of Sciences | Sradnick J.,Johann Friedrich Blumenbach Institute | Sradnick J.,TU Dresden | Klopfel A.,Johann Friedrich Blumenbach Institute | Elsner N.,Johann Friedrich Blumenbach Institute
Biological Journal of the Linnean Society | Year: 2012

The closely related grasshopper species Stenobothrus rubicundus and Stenobothrus clavatus are known to hybridize in a very narrow contact zone on Mt. Tomaros in northern Greece. These species produce very different and complex courtship songs accompanied with visual display. We analyzed the courtship songs and underlying stridulatory movements of the hind legs in natural hybrids from Mount Tomaros. The two species were also hybridized in the laboratory and their songs were compared with the songs of the natural hybrids. Some hybrid songs were shown to have intermediate features between parental songs, whereas other hybrid songs comprised completely new elements. The clavatus-like song elements were found to dominate in hybrid songs. These song features may influence the mating success of hybrid males in the contact zone. A comparison of hybrid songs with the song pattern of the north European S.rubicundus populations allowed us to suggest a scenario of S.rubicundus and S.clavatus origin. © 2012 The Linnean Society of London. Source

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