FNZ 58 - Alysiinae (Insecta: Hymenoptera: Braconidae) - Introduction
Berry, JA 2007. Alysiinae (Insecta: Hymenoptera: Braconidae). Fauna of New Zealand 58, 95 pages.
(
ISSN 0111-5383 (print),
;
no.
58.
ISBN 978-0-478-09390-2 (print),
).
Published 07 Sep 2007
ZooBank: http://zoobank.org/References/07C9F5B3-C83B-4D1F-8792-D356E96CFECE
Introduction
The hymenopteran fauna of the New Zealand biogeographic region is poorly known. Berry (2005) recorded approximately 670 described species and a further 900 or so undescribed or undetermined species based on material in collections and publications. Even though the general level of resolution is low to patchy, several hymenopteran families stand out as being particularly poorly documented — one of these is the ichneumonoid family Braconidae. A scant 100 or so species in the following fifteen subfamilies have been recognised: Agathidinae, Alysiinae, Aphidiinae, Betylobraconinae, Blacinae, Braconinae, Cheloninae, Doryctinae, Euphorinae, Helconinae, Hormiinae, Macrocentrinae, Opiinae, Rhyssalinae, and Rogadinae. This compares to a world total of 29 to 45 subfamilies, depending on the classification used (Wharton et al. 1997). Only one subfamily-level revision for New Zealand Braconidae has previously been published, that of the chelonines by Walker & Huddleston (1987). The nearest continental braconid fauna, that of Australia, is also patchily known (Austin et al. 2004).
The subfamily Alysiinae is a monophyletic group, easily recognised by their broad exodont, or outwardly directed, non-overlapping mandibles, which are used to assist in escape from the host puparium (Wharton 1984). The alysiines are the only parasitic Hymenoptera in New Zealand known to possess this character state, so placement to subfamily level is not problematic. In other biogeographic regions only a few relatively rare taxa outside the Alysiinae have exodont mandibles, for example, the eulophid genus Exodontomphale Bouček, known from Australia and the Southern USA (Bouček 1988), the proctotrupoid family Vanhorniidae, the ichneumonid genus Idiogramma Förster, and a few other Braconidae (Wharton & Austin 1991).
The subfamily is traditionally divided into two tribes, the Alysiini and the Dacnusini, which can be distinguished by the presence or absence, respectively, of the 2nd cubital cross-vein (r-m) (Wharton 2002). The placement of brachypterous or apterous genera can be difficult (Wharton 1980). However, the New Zealand fauna appears, unusually, to contain very few reduced-wing alysiine species, or even individuals (see discussion under Asobara antipoda). The New Zealand dacnusine fauna is depauperate, consisting of 5 species in 3 genera; 1 of which is introduced. The alysiines are more speciose: 16 species in 5 genera are treated in this publication, the majority of which (11 species) are not known outside of New Zealand.
History of New Zealand Alysiinae
In their 1991 catalogue, Valentine & Walker recorded just 5 alysiine species in 4 genera from New Zealand: Alysia manducator (Panzer), A. stramineipes Cameron, Aphaereta aotea Hughes & Woolcock, Dacnusa areolaris (Nees), and Asobara antipoda Ashmead (as Phaenocarpa antipoda).
Alysia stramineipes was described from the South Island in 1898, but according to Wharton (1986, p.455) the male holotype (the only specimen the description was based on), is a helconine (Braconidae: Helconinae: Diospilini). Thus the first alysiine described from New Zealand was Asobara antipoda, from the Chatham Islands in 1900. Dacnusa areolaris is an accidentally introduced species; the earliest collection year is 1921. Alysia manducator was introduced from the United Kingdom in the summer of 1926/1927 for the control of blow flies (Heath & Bishop 1989; see comments under species treatment). Aphaereta aotea was described from the North Island much later in 1976.
Berry (2005) recorded an additional 13 species in the following genera: Alysia Latreille, Aphaereta Förster, Asobara Förster, Aspilota Förster, Chorebus Haliday, Chaenusa Haliday, and Dinotrema Förster.
Biology
Alysiine braconids are endoparasitoids of cyclorrhapous dipterans, with oviposition into the egg or larva of the host and emergence from the host puparium. Wharton (2002) used this character, along with the possession of exodont mandibles, to define the subfamily. Almost all Dacnusini are parasitoids of leaf- and stem-mining dipterans, usually Agromyzidae (Wharton 2002), but Alysiini attack a wide range of dipteran hosts from at least 20 different families (Wharton 1980).
Table 1 summarises host records for alysiine braconids, excluding adventive species outside New Zealand (see Appendices 2–3 for details). Adventive parasitoids have been reared from both endemic and adventive hosts. Very little is known of the biology of endemic species. The intentionally introduced biological control agent Alysia manducator has been recorded from six calliphorid species in New Zealand, including two endemics.
Faunal relations
Twenty-one species in 8 genera of alysiine braconids are recorded from New Zealand in this revision. Of these, 15 species (around 70%) are not known outside New Zealand. None of the genera are endemic; the newly described Chorebus rodericki is difficult to place at the generic level, but is not placed in a new genus (for discussion see remarks under species treatment).
One species, Aspilota andyaustini, is shared with Australia. The remaining 5 species are adventive: 1 was deliberately introduced as a biological control agent (Alysia manducator, for the control of blowflies), and 4 were accidentally introduced (Aphaereta pallipes, Asobara persimilis, A. tabida, and Dacnusa areolaris).