Biocontrol introduction
Target pest: Costelytra giveni (Coleoptera: Scarabaeidae), New Zealand grass grub
Agent introduced: Dasyuromyia sp. (Diptera: Tachinidae)
Imported:
1968-69
Import source:
Argentina
Import notes:
Cameron et al. (1989) - eleven parasitic tachinid species (including a total of 364 Dasyuromyia - a mix of Dasyuromyia sp., D. inornata, D. tarsalis, D. sternalis and D. sarcophagidea [numbers of individual species were not recorded]) were imported from Argentina between 1968 and 1969, but none of these developed successfully on C. giveni or Odontria [like Costelytra, a melolonthine scarab genus] species and few were released.
Released:
1968-69
Release details:
Cameron et al. (1989) - a total of 94 Dasyuromyia were released in the Nelson region of the South Island [see species listed in the Cameron et al. (1989) entry in the ‘Import notes’ section above - numbers of individual species released were not recorded].
Establishment:
Cameron et al. (1989) - no Dasyuromyia spp. were recovered from the field following release.
General comments:
Taxonomic note (8 April 2025) - a species of scarab beetle was described as Rhizotrogus zealandicus by White in 1846 from two specimens collected in the Wellington region. In 1952 Given described the genus Costelytra with the New Zealand grass grub as the type species, naming it C. zealandica, considering it conspecific with White’s Rhizotrogus zealandicus. However, Coca-Abia & Romero-Samper (2016) found differences between Given’s description of C. zealandica (i.e. New Zealand grass grub) and White’s specimens, and renamed the New Zealand grass grab Costelytra giveni, reserving the name C. zealandica (syn R. zealandicus) for the species described by White, considered by Coca-Abia & Romero-Samper (2016) likely to be a shrubland or forest species from the Wellington region. [All information from Coca-Abia & Romero-Samper (2016).]
References
Cameron PJ, Hill RL, Bain J, Thomas WP (1989). A Review of Biological Control of Invertebrate Pests and Weeds in New Zealand 1874-1987. Technical Communication No 10. CAB International Institute of Biological Control. DSIR Entomology Division. 424p.
Coca-Abia MM, Romero-Samper J (2016). Establishment of the identity of Costelytra zealandica (White 1846) (Coleoptera: Scarabeidae: Melolonthinae) a species commonly known as the New Zealand grass grub. New Zealand Entomologist 39(2): 129-146 https://doi.org/10.1080/00779962.2016.1230254
