Biocontrol introduction

Target pest: Saissetia oleae (Hemiptera: Coccidae), black scale

Agent introduced: Scutellista caerulea (Hymenoptera: Pteromalidae) = Scutellista cyanea Motschulsky

Imported: 1921, 1922

Import source: Australia

Released: 1921, 1922

Release details: Cameron et al. (1989) - released at Nelson.

Establishment: Cameron et al. (1989) - did not establish. Thorpe (2013) - on 17 April 2013, a live specimen was captured in the wild in Auckland. It is unclear if the new specimen represents a descendant of the original stock released in Nelson, or a new incursion from overseas. The balance of evidence favours the latter hypothesis, since Auckland is far from Nelson, and the species has not been seen in New Zealand for nearly a century. Thorpe (2015) - on 21 March 2015 a further female specimen was collected at the same site (the Tamaki campus of Auckland University) as the 2013 find. Meanwhile, a parasitised black scale (Parasaissetia nigra) was collected from the city campus of Auckland University on 13 March 2015, from which a male Scutellista caerulea subsequently emerged. The question remains unanswered whether these specimens are descendants of the 1921 release in Nelson, or else represent a new incursion from overseas. At any rate, the species would appear to be established now.

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.

Thorpe SE (2013). Scutellista caerulea (Fonscolombe, 1832) (Hymenoptera: Pteromalidae), new to New Zealand for the second time! Biodiversity Data Journal 1: e959 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3964711/

Thorpe SE (2015). Scutellista caerulea (Hymenoptera: Pteromalidae) makes another reappearance in New Zealand. The Weta 49: 45-46