Cb. Phillips et al., SOUTH-AMERICAN ORIGINS OF MICROCTONUS-HYPERODAE LOAN (HYMENOPTERA, BRACONIDAE) ESTABLISHED IN NEW-ZEALAND AS DEFINED BY MORPHOMETRIC ANALYSIS, Biocontrol science and technology, 7(2), 1997, pp. 247-258
Eight South American geographic populations of the thelytokous parasit
oid Microctonus hyperodae Loan (Hymenoptera: Braconidae) were released
in New Zealand in 1991 to assist in the suppression of the pasture pe
st Listronotus bonariensis (Kuschel) (Coleoptera: Curculionidae). With
one exception, parasitoids from each South American geographic popula
tion were released in equal numbers at each New Zealand release site.
It was postulated that the South American geographic population(s) bes
t suited to the conditions encountered at each New Zealand release loc
ality would eventually become prevalent there. A morphometric analysis
of adult parasitoids of known South American origins, reported previo
usly, allowed M. hyperodae derived from west of the Andes (i.e. two co
llection sites in Chile) to be distinguished from parasitoids derived
from east of the Andes (i.e. three collection sites in Argentina and o
ne each in Brazil and Uruguay). Parasitoids derived from a fourth site
in Argentina (S. C. de Bariloche) could not be clearly discriminated
from either the 'east of the Andes' or 'west of the Andes' categories.
A morphometric analysis of M. hyperodae adults collected from Jive of
the New Zealand release sites from 1992-1994 is presented in this con
tribution. The analysis indicated that parasitoids derived from east o
f the Andes were significantly more prevalent than expected. The possi
ble reasons for the initial success in New Zealand of one or more east
of the Andes populations include the greater fecundity of M. hyperoda
e collected in Uruguay and the likelihood that M. hyperodae from east
of the Andes co-evolved more recently with the stock from which New Ze
aland's L. bonariensis was founded.