FNZ 15 - Ambositrinae (Insecta: Hymenoptera: Diapriidae) - Introduction
Naumann, ID 1988. Ambositrinae (Insecta: Hymenoptera: Diapriidae). Fauna of New Zealand 15, 168 pages.
( ISSN 0111-5383 (print), ; no. 15. ISBN 0-477-02535-8 (print), ). Published 30 Dec 1988
The Ambositrinae are one of the major hymenopterous components of the New Zealand forest fauna. Probably all are parasites of the immature stages of nematocerous Diptera, which are also abundant in the litter and low vegetation of New Zealand forests. The present-day austral-disjunct distribution of the Ambositrinae (Naumann 1982) reflects a Gondwana radiation no later than the Cretaceous, and the morphological diversity within the subfamily evidences a long evolutionary history.
The New Zealand forest floor fauna as a whole has been regarded as a Tertiary fauna which survived the Pleistocene glaciations, often in relatively small refugia, and which has colonised in strength the expanding post-glacial forests (Dugdale in Wardle et al. 1983). Because of New Zealand's long isolation this colonisation has taken place largely in the absence of competition from more recently evolved hymenopterous taxa. It is not surprising, then, that New Zealand's Ambositrinae are of uncommon interest.
The bibliography of original work on the New Zealand Ambositrinae is meagre, and concerns predominantly two species. Cameron's (1889) description of the genus Betyla for B. fulva, represented then by a single female from Greymouth, is the first description of a diapriid now known to belong to the Ambositrinae. Marshall (1892a) erected Tanyzonus for a new species, bolitophilae, of which he had female and male specimens reared from the glow-worm Arachnocampa luminosa (Skuse) (Diptera: Keroplatidae) (see also Hudson 1892, 1893). However, only months later Marshall (1892b) synonymised his species with B. fulva. This synonymy was doubted by Brues (1922) and Gourlay (1927), but has generally been accepted - e.g., by Kieffer (1916), who rediagnosed Betyla and B. fulva, and included Betyla in his key to world genera of Belytinae. Brues (1922) erected Parabetyla for a new species, P. spinosa, based on a single female from Dun Mountain NN, and provided a key which included Betyla and Parabetyla. Masner (1961) proposed the subfamily Ambositrinae for a new genus, Ambositra, from Africa and Madagascar. Subsequently Betyla, Parabetyla, and a number of other principally Southern Hemisphere diapriid genera were included in the Ambositrinae, and the Gondwana associations of the subfamily were appreciated for the first time (Masner 1969). Naumann's (1982) revision of the Australian Ambositrinae included a synopsis of world genera, diagnoses of Betyla, Parabetyla, and an undescribed New Zealand genus, and a discussion of the phylogenetic and biogeographic relationships of the New Zealand taxa then known.
This contribution, the result of a study of more than 3500 specimens over a period of 7 years, describes and names New Zealand taxa as fully as the available material allows. However, much remains to be done within New Zealand, especially as regards rearing and the association of sexes.