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Call Structure Variability and Field Survival among Bushcrickets Exposed to Phonotactic Parasitoids


Allen, GR, Call Structure Variability and Field Survival among Bushcrickets Exposed to Phonotactic Parasitoids, Ethology, 106, (5) pp. 409-423. ISSN 0179-1613 (2000) [Refereed Article]

DOI: doi:10.1046/j.1439-0310.2000.00550.x


Calling adult males of the univoltine bushcricket Sciarasaga quadrata are subject to significant mortality from the phonotactic parasitoid fly Homotrixa alleni. These flies kill their host within 14d and act as a constant 'filter' on the survival of male bushcrickets. In this study, I investigate both short-term and lifetime variability in male call structure and compare the call properties of collections of males made over a 3-mo calling season to establish whether there are any significant differences in the call properties of males surviving the length of the calling season. Call frequency, chirp length, interchirp length, chirp rate, file teeth used to make a chirp and duty cycle all showed good differentiation among males and significant repeatability: (1) within a calling bout (0.57-0.88), (2) between successive nights (0.27-0.83), and (3) over a males lifetime (0.15-0.43). Frequency and to a lesser extent chirp length showed low variability within and among males whereas interchirp length was the most flexible and dynamic call property. As males aged, chirp length, which is produced by one wing closure, and its correlate, teeth per chirp, significantly increased and chirp rate significantly decreased. Over the calling season chirp length and teeth per chirp showed strong directional shifts. Shorter chirp males were lost from the calling population, indicating that flies may use chirp length as a cue in host location. The implications of this result are discussed in relation to the reproductive fitness of male S. quadrata and within the context of host location and sensory bias in phontotactic parasitoids.

Item Details

Item Type:Refereed Article
Research Division:Biological Sciences
Research Group:Zoology
Research Field:Invertebrate biology
Objective Division:Expanding Knowledge
Objective Group:Expanding knowledge
Objective Field:Expanding knowledge in the environmental sciences
UTAS Author:Allen, GR (Associate Professor Geoff Allen)
ID Code:19189
Year Published:2000
Web of Science® Times Cited:8
Deposited By:Agricultural Science
Deposited On:2000-08-01
Last Modified:2011-10-04

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