Glossary

The following glossary is intended only to clarify a number of more unusual terms used in the introductory text. The morphological terms are explained in a separate section, general morphology.

Aculeata: a monophyletic group of apocritan (q.v.) Hymenoptera consisting of the superfamilies Chrysidoidea, Apoidea and Vespoidea. This group includes the ants, bees and social wasps. The ovipositor of aculeates is used for venom injection instead of egg-laying.

Afrotropical: a region equivalent to the classical Ethiopian region, consisting of Africa south of the Sahara desert, Madagascar, and all associated islands including St Helena.

Amphitropical: a form of distribution in which a group is present in both the northern and the southern hemispheres but absent from the tropics.

Apocrita (n.) [apocritan adj]: a major monophyletic group of the Hymenoptera in which the first abdominal segment has fused with the thorax, forming the mesosoma. The remaining portion of the abdomen is referred to as the metasoma; the first segment of the metasoma is the second abdominal segment. The characteristic “wasp-waist” of Hymenoptera is the result of the constricted connection of the first metasomal segment and the propodeum.

Arrhenotoky: the normal mechanism of reproduction in Hymenoptera whereby males are produced from haploid unfertilized eggs. Females are produced from diploid eggs.

Deuterotoky: a form of parthenogenesis whereby unmated females may produce both male and female offspring.

Facultative arrhenotoky: the ability of Hymenoptera females to control egg fertilization by allowing sperm egress from the spermatheca, thus giving them the ability to select the sex of the offspring.

Gondwanan: referring to Gondwana, the Mesozoic southern continent consisting of Africa, India, South America, Antarctica, Australia/southern New Guinea and New Zealand (Howarth, 1981). South America, Antarctica and Australia remained united until 60-80 mya, with the temperate areas sharing a common biota. Examples are the plant genera Nothofagus and Araucaria (White, 1998), and the ichneumonid subfamily Labeninae.

Holarctic: a region consisting of the Palearctic (= Eurasia and northern Africa) and the Nearctic (= North America to the Isthmus of Tehuantepec).

Holometabolous insect orders: those having postembryonic development consisting of larval, pupal and adult stages. They are the Coleoptera, Diptera, Hymenoptera, Lepidoptera, Mecoptera, Neuroptera, Strepsiptera and Trichoptera.

Hyperdiverse holometabolous insect orders: the Coleoptera, Diptera, Hymenoptera and Lepidoptera, each of which consists of more than 100,000 species.

Hyperparasitoid: a parasitoid that develops by feeding on or within a primary parasitoid that is still developing on its host.

Idiobiont: a parasitoid whose larval growth is on or within a host which has been developmentally arrested at oviposition. The host is usually relatively mature and concealed in a protected situation, such as wood-boring larvae or cocooned prepupae/pupae.

Idiobiosis: the lifeway of an idiobiont (q.v.).

Koinobiont: a parasitoid whose larval growth is on or within a host that continues to develop after oviposition. The host is often an early or mid-instar larva, exposed or weakly concealed; parasitoid development accelerates after the host has spun a cocoon or constructed a pupation chamber.

Koinobiosis: the lifeway of a koinobiont (q.v.).

Macrolecithal: a type of parasitoid egg that is both large and rich in yolk, so the embryo will eclose as a first instar larva having developed entirely on the food contents of this egg. Such eggs are usually produced throughout a synovigenic (q.v.) parasitoid’s life and their production requires a protein-rich diet, usually obtained from host-feeding. Such eggs are usually typical of idiobionts.

Microlecithal: a type of parasitoid egg that is small and has a small yolk. Such eggs generally absorb nutrients from host after oviposition, before they eclose. Microlecithal eggs are predominantly found in pro-ovigenic (q.v.) koinobiont endoparasitic species and may be viewed as a way of transferring the physiological cost of egg maturation from the parasitoid to the host.

Neantarctic: a region consisting of temperate southern South America (central and southern Chile, and Patagonia) and associated sub-Antarctic islands. The Neantarctic fauna is often considered to have a Gondwanic (q.v.) origin.

Palaearctic/Oriental interface: many primarily Palearctic organisms have ranges that extend southwards into the Oriental region in the mountains of northern India and Burma. Such organisms cannot really be said to have a truly “Oriental” distribution, but strictly speaking they are present in the Oriental region and generally recorded as such in various catalogues (e.g., Yu & Horstmann, 1997). A similar conundrum occurs in the New World where obviously Nearctic genera have ranges that extend south into the Isthmus of Tehuantepec.

Parasitoid: an organism that develops for part of its life on or within a single host organism and kills it as a direct or indirect result of that development.

Pro-ovigenic: parasitoids that have a full complement of mature eggs at eclosion; the eggs were produced from nutrients obtained during larval development.

Pseudohyperparasitoid: a parasitoid that attacks a primary parasitoid after the primary has completed the destruction of its own host.

Symphyta: one of the two suborders of Hymenoptera in traditional classifications. It included the sawfly and woodwasp superfamilies Xyeloidea, Tenthredinoidea, Pamphilioidea, Cephoidea, Siricoidea, Xiphydrioidea and Orussoidea. It is now considered to be a paraphyletic assemblage of basal Hymenoptera lineages and is not formally recognized (Vilhelmsen, 2001; Schulmeister et al., 2002). “Symphyta” is still used as a term of convenience when referring to the sawflies and woodwasps.

Synovigenic: parasitoids that do not have a full complement of eggs at eclosion and that continue to mature them throughout adult life; females require host-supplied nutrients for egg production.

Thelytoky: a form of parthenogenesis whereby diploid females are produced from unfertilized eggs.

Venom: any secretion produced by an adult female Hymenopteran from the venom gland or other structure associated with the female reproductive tract. When injected, a venom may paralyse a host either permanently or temporarily, or modify the host in some way that benefits the parasitoid.

References

Howarth, M.K. 1981. Palaeogeography of the Mesozoic, pp.197-220. In: Cocks, L.R.M. (ed.) The Evolving Earth. Cambridge University Press: Cambridge. 264pp.

Schulmeister, S., Wheeler, W.C. & Carpenter, J.C. 2002. Simultaneous analysis of the basal lineages of Hymenoptera (Insecta) using sensitivity analysis. Cladistics, 18: 455-484.

Vilhelmsen, L. 2001. Phylogeny and classification of the extant basal lineages of the Hymenoptera (Insecta). Zoological Journal of the Linnean Society, 131: 393-442.

White, M.E. 1998. The Greening of Gondwana. Kangaroo Press: E. Roseville, NSW. 256 pp.

Yu, D.S. & Horstmann, K. 1997. A catalogue of World Ichneumonidae (Hymenoptera). Memoirs of the American Entomological Institute, 58: 1-1558.