Allozyme markers to help define the South American origins of Microctonus hyperodae (Hymenoptera: Braconidae) established in New Zealand for biological control of Argentine stem weevil

Abstract

The thelytokous parasitoid, Microctonus hyperodae Loan, was collected from eight South American locations and introduced to New Zealand in 1991 for biological control of Argentine stem weevil, Listronotus bonariensis (Kuschel) (Coleoptera: Curculionidae). Parasitoids from each population were released in equal numbers at each New Zealand site to give them the same opportunities to establish. Population markers have been sought to identify the South American geographic populations that have become most successful in New Zealand. These would assist in determining the importance of concepts such as climate matching and host-parasitoid coevolution to the establishment of natural enemies in new regions for biological control. Vertical polyacrylamide electrophoresis was used to survey 16 enzymes and ten calcium binding proteins, and this paper reports variation at three putative loci. Malate dehydrogenase, a dihydrolipoamide dehydrogenase isozyme and a calcium binding protein exhibited clear genetic variation, each with two alleles. All M. hyperodae isofemale lines from east of the Andes mountains shared one genotype, all but one from west of the Andes shared another, while a population from within the Andes contained both genotypes. This variation was highly congruent with previously described morphometric variation. At two loci, the maintenance of heterozygotes, and the absence of homozygotes, within isofemale lines suggested M. hyperodae thelytoky is apomictic.

East meets west: adaptive evolution of an insect introduced for biological control

“…It lays one egg per adult L. bonariensis (its only known host), the larva develops within the living, active weevil then emerges to pupate, while the host dies due to the parasitism (Loan & Lloyd 1974). Microctonus hyperodae reproduces by apomictic parthenogenesis (Loan & Lloyd 1974; Iline & Phillips 2004). No males of M. hyperodae have been observed in South America (Loan & Lloyd 1974), nor have any been seen during >10 years of mass rearing and field monitoring in New Zealand (McNeill et al .…”

“…Morphometric variation occurred in the number of antennal segments, the size of the radial cell, stigma and basitarsus 3, and the shape of the petiole (Phillips & Baird 1996). Protein variation (Iline & Phillips 2004) occurred at loci for malate dehydrogenase (MDH), dihydrolipoamide dehydrogenase (DDH2), and a calcium‐binding protein (CBP9), while nucleotide sequence variation occurred in microsatellite and mitochondrial 16S gene regions (Winder et al . 2005).…”

“…1). Data from the protein (Iline & Phillips 2004) and genomic (Winder et al . 2005) studies corroborated the existence of the eastern and western biotypes, but showed that the San Carlos de Bariloche population was a mixture of the eastern and western biotypes (3 E : 5 W), rather than a third biotype.…”

Founder effects and phenotypic variation in Adelges cooleyi, an insect pest introduced to the eastern United States

“…We sought to measure the genetic footprint of an insect introduction by analysis of genetic diversity in native and introduced ranges. Regarding inadvertent insect introductions, many researchers have considered genetic variation in native and introduced populations (Grapputo et al 2005;Iline and Phillips 2004;Scheffer and Grissell 2003;Stadler et al 2005;Taylor et al 2004). …”

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

“…Some species are sexual; M. hyperodae is parthenogenetic. Inheritance patterns of allozyme markers suggest that the parthenogenetic reproduction of M. hyperodae occurs without meiosis and the associated crossing over between homologous chromosomes (Iline and Phillips 2004). M. hyperodae daughters appear, therefore, to be genetically identical to their mothers, except when new mutations arise.…”