Target pest: Eriococcus coriaceus (Hemiptera: Eriococcidae), gum tree scale
Agent introduced: Stathmopoda melanochra (Lepidoptera: Oecophoridae)
Cameron et al. (1989) - in 1932 and 1933 more than 100 S. melanochra adults were imported from Australia in two shipments.
Cameron et al. (1989) - imported adults were released in Nelson, South Island: six in 1932 and 91 in 1933.
Cameron et al. (1989) - Stathmopoda melanochra has become established in Nelson and Christchurch in the South Island, and Hawke's Bay and Manawatu in the North Island.
Impacts on target:
Cameron et al. (1989) - Stathmopoda melanochra is never abundant enough to exert any marked effect on E. coriaceus populations.
Cameron et al. (1993) - Stathmopoda melanochra, in conjunction with Rhyzobius ventralis, is categorised as exerting ‚Äúcomplete‚ÄĚ control (defined as ‚Äúcontrol of the target over an extensive area so that pest outbreaks are rare or other control treatments are rarely necessary‚ÄĚ) over E. coriaceus. [Although R. ventralis is principally responsible for exerting this control - see Cameron et al. (1989) entry above in this section, and the R. ventralis introduction entry.]
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.
Cameron PJ, Hill RL, Bain J, Thomas WP (1993). Analysis of importations for biological control of insect pests and weeds in New Zealand. Biocontrol Science and Technology 3(4): 387-404