Description and field biology ofMicroctonus hyperodae Loan, n. sp. [Hymenoptera: Braconidae, Euphorinae] a parasite ofHyperodes bonariensis in South America [Coleoptera: Curculionidae]

Biology of the Introduced Biocontrol AgentMicroctonus hyperodae(Hymenoptera: Braconidae) and Its HostListronotus bonariensis(Coleoptera: Curculionidae) in Northern New Zealand

“…As a consequence, Barker and Addison (2006) reported the rate of overwintering survival of L. bonariensis adultsÑthe primary control on number of adult L. bonariensis at the onset of the reproductive period in spring for these northern New Zealand populationsÑ was signiÞcantly correlated with the incidence of parasitism in autumn. These results are consistent both with the observation of Barker et al (1989a) that in the absence of parasitism, L. bonariensis populations exhibited density-dependent mortality over winter, and with the observation of Loan and Lloyd (1974), who noted in South America, a more protracted survival in parasitized overwintering L. bonariensis than their nonparasitized counterparts.…”

“…Most Microctonus species, including M. hyperodae, are solitary parasitoids (Loan and Holdaway 1961;Loan and Lloyd 1974;Morales and Hower 1981;Goldson et al 1990aGoldson et al , 1992, but a few develop gregariously (Loan 1967, Luff 1976, Rieske et al 1989, Cuda and Burke 1991, Shaw and Huddleston 1991, Tironi et al 2004, Gerard et al 2007). Parasitism renders the host sterile almost immediately and results in host death when the fully developed parasitoid larva or larvae emerge to pupate.…”

A Morphometric Method to Assist in Defining the South American Origins of Microctonus hyperodae Loan (Hymenoptera: Braconidae) Established in New Zealand

“…T hus, it is perhap s not surprisi ng that the grou p of insects exam ined in this contribu tion which most closely rese mbled Loan and Lloyd' s (1974 ) descript ion w as that w hich was derive d from the sam e locatio n approxi mately 18 years later . For example, the parasitoi ds from S. C. de Bariloch e w ere the only populati on of the eigh t assesse d to have a m ean of 20 segm ents/antenn a (T able 2), as recorde d earlie r by Loan and Lloyd (1974) . Given that all of the insects exam ined in this stud y w ere reared on one host specie s under unifor m conditio ns in the laborato ry, it is unlikely that the observe d inter-po pulatio n m orpholo gical variatio n was cause d by environ menta l factors .…”

“…It w as recogniz ed that biologic al contro l agents w ould integrat e w ell w ith thes e efforts (Goldson et al, 1990 ) and the South Am erica n endopar asitoid M icrocton us hyperod ae Loan (H ym enopter a: B raconida e, Euphorin ae) was identi® ed as a candidat e for introdu ction to New Zealand (Loan & Lloyd , 1974) . This thelytok ous, koinobi ontic parasito id is distribu ted through out tem perate South Am erica (Goldso n et al, 1990 ) where its only kno wn host is the adult stage of the Argentin e stem weevil (Loan & Lloyd , 1974). In 1989 ±90, more than 13 000 adult A rgentin e stem weevils were im ported from South A meric a and 247 M. hyperod ae w ere reared from them (Goldso n et al, 1990).…”

Early Impact of Endoparasitoid <I>Microctonus hyperodae</I> (Hymenoptera: Braconidae) After Its Establishment in <I>Listronotus bonariensis</I> (Coleoptera: Curculionidae) Populations of Northern New Zealand Pastures

“…The indicated reductions in fecundity are broadly consistent with the biology of the parasitoid and its known rapid sterilization of parasitized hosts (Loan and Lloyd 1974). Within generations, the numbers of L. bonariensis adults at the end of the life cycle were related primarily to survival rate of larvae and pupae during the without-Microctonus period and this remained the case in the with-Microctonus period.…”