Antennal Hammers: Echos of Sensillae Past
Many hosts of parasitoids live in concealed environments such as within plants tissue and wood, and therefore they are difficult to find. This is likely to be especially true when concealed hosts are in the pupal stage and thereby silent and immobile. Cry
- PDF / 537,505 Bytes
- 12 Pages / 439.37 x 666.142 pts Page_size
- 11 Downloads / 179 Views
Antennal Hammers: Echos of Sensillae Past Nina Laurenne and Donald L.J. Quicke
Abstract Many hosts of parasitoids live in concealed environments such as within plants tissue and wood, and therefore they are difficult to find. This is likely to be especially true when concealed hosts are in the pupal stage and thereby silent and immobile. Cryptine ichneumonids collectively have a wide host range including members of several insect orders with different degrees of concealment. Many cryptine genera show a morphological adaptation to finding concealed hosts; their antennal tips are modified into a hammer-like structures that are used to tap the substrate. This vibrational sounding (¼echolocation though solid media) is typical to the tribe Cryptini and it has multiple origins within the subfamily. We show that vibrational sounding is associated with antennal modification and the usage of wood-boring buprestid and cerambycid beetles, and suggest, based on an apparent transition series, that the hammers are derived from mechano-sensilla within the Cryptinae.
16.1
Introduction
The Ichneumonidae is one of the largest insect families with more than 20,000 described species (Yu et al. 2005), though, according to Gaston and Gauld (1993), the real number of species may reach more than half of a million. Ichneumonid wasps are cosmopolitan and whereas most species are parasitoids of other insects N. Laurenne Museum of Natural History, Entomology Division, University of Helsinki, P.O. Box 17, (P. Arkadiankatu 13), 00014 Helsinki, Finland e-mail: [email protected] D.L.J. Quicke Department of Life Sciences, Imperial College London, Silwood Park Campus, Ascot, Berkshire SL5 7PY, UK Department of Entomology, Natural History Museum, London SW7 5BD, UK
P. Pontarotti (ed.), Evolutionary Biology – Concepts, Molecular and Morphological Evolution, DOI 10.1007/978-3-642-12340-5_16, # Springer-Verlag Berlin Heidelberg 2010
271
272
N. Laurenne and D.L.J. Quicke
and in some cases spiders, their way of life varies remarkably. Unlike simple parasites, parasitoids always kill their hosts that are typically larvae or pupae of various Lepidoptera, Coleoptera and Diptera. Parasitoid life history strategies are commonly divided into two classes, the koinobionts and idiobionts (Askew and Shaw 1986; Godfray 1994; Quicke 1997). These two life strategies differ from each other considerably, but the defining difference between them is that idiobionts do not permit their host to carry on developing after parasitisation. In those cases in which the host is a larval stage, it is typically paralysed by the female wasp’s venom. In contrast to idiobionts, the hosts of koinobionts are allowed to continue their development after parasitisation until they reach a suitable stage to be consumed by parasitoid larvae. Several other features are associated with these life strategies, for example, koinobionts are most usually endoparasitoids with relatively narrow host ranges as they have to be able to adapt to the host’s immunological defenses. Idiobio
Data Loading...
