UK mantis forums newsletter

UKMF Newsletter issue 6
Mantodea Abstracts, November 2010 – December
2011
Compiled by Gillian Higgins
The abstracts for scientific papers related to the study of mantises are listed below.
Allen, L. E., Barry, K. L., Holwell, G. I. (2011), Mate Location and Antennal Morphology in
the Praying Mantid Hierodula majuscula. Australian Journal of Entomology. 2011, doi:
10.1111/j.1440-6055.2011.00843.
Abstract: Many sensory modes can be exploited to determine the location of potential
mates. In insects, long-distance location primarily involves chemical or acoustic cues,
whereas short-distance communication mainly utilises visual or tactile cues. The structural
complexity of the environment may influence the transmission of information, and therefore,
it is common to see multiple sensory modes employed to increase the likelihood of accurate
mate location. Praying mantids are known to use airborne chemicals for long-distance
location and visual cues in close proximity. This study examined which types of cues are
used for mate location in an unstudied species, Hierodula majuscula, from Queensland,
Australia. The timing of female pheromone emission during ‘calling’ periods reached a peak
at 3:00 h, with the majority of females assuming a calling posture at this time. Scanning
electron microscopy was used to confirm the presence of basiconic sensilla (used for
chemical reception) on male antennae, and males successfully responded to female
chemical cues and subsequently located potential mates. Males were not as successful at
finding females when restricted to using visual cues.
Allen, L. E., Barry, K. L., Holwell, G. I., Herberstein, M. E., Perceived Risk of Sperm
Competition Affects Juvenile Development and Ejaculate Expenditure in Male Praying
Mantids. Animal Behaviour, 2011, 82 (5): 1201-1206,
Abstract: Sperm competition occurs when a female mates with more than one male, and
the sperm of those males compete directly over fertilizing her eggs. In polyandrous animals,
males can respond to the perceived risk of sperm competition by flexibly adjusting aspects of
their development and reproductive investment. In high-risk scenarios we might expect
males to accelerate development so as to mature quickly and locate receptive females first
and/or transfer more sperm so as to outcompete rival sperm. We examined these
predictions using the false garden mantid, Pseudomantis albofimbriata, a medium-sized
praying mantid found on the east coast of Australia. Males are less than half the mass of
females. Sexual cannibalism occurs in up to 40% of interactions, highlighting the importance
of investing optimally in reproductive opportunities for males. We housed juvenile males in
two operational sex ratio treatments: three males, one female (high risk of sperm
competition) and one male, three females (low risk). We found no evidence of accelerated
development in the high-risk group; instead, high-risk males took longer to mature. Possibly,
males exposed to a higher risk of sperm competition delay maturity in order to invest in
testes development and sperm production. We also found that males reared in the high-risk
treatment transferred significantly more sperm than males reared in the low-risk treatment,
providing evidence of strategic ejaculation in male P. albofimbriata. This is the first study
demonstrating a male response to the perceived risk of sperm competition via delayed
development and increased ejaculate investment in praying mantids.
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