EFFECTIVE PARASITE

Poverty Bay Herald, Volume LIX, Issue 17909, 13 October 1932, Page 4

EFFECTIVE PARASITE

PINE TREE BORER EXPERIMENTS AT CAWTHRON (Per Press Association.) NELSON, last night. During the last few years the attention of those interested in the commercial production of pine trees has been drawn to the activities of the blue horntail borer, which is now well established in the Dominion. Though it does not damage vigorous trees, it is much too common to be discarded as of minor importance. The parasito of the borer being known to occur in England, Dr. D. Miller, director of the entomological department of the Cawthron Institute, arranged with the director of the Farnham Royal Parasite Laboratory for the parasito to be studied and supplies to be sent to New Zealand. This was quite a new departure in biological control, in that it was the first attempt made to transport a parasite of a wood-boring insect from one country to another and establish it in that environment. Several consignments of the parasites were sent to the Cawthron Institute, where the work has been carried out ’as one of the major operations. Though many of the parasites perished before reaching maturity, a considerable number survived, and many were liberated among borer-infected trees near Blenheim, Hanmer, and Moutere, while others were retained at Cawthron Institute. That there was some possibility of the parasite succeeding in this country was shown by the activities of the insect in locating the position. ,of its victims in infested trees prior to piercing tho bark, and laying its eggs on the boring grubs. However, whether this had been successfully accomplished or not could not be practicably ascertained, the parasites and borer being concealed within the timber. In consequence, a careful watch was kept for the emergence of adult parasites from trees in which the parasites were known to have laid their eggs. During the last week or two these emergences have been taking place in the insectory at the Cawthron Institute, and there is every reason to expect that the same is taking place in the plantations at Blenheim, Hanmcn and Moutere.

Tho appearance of this, the first generation of parasite to be reared in New Zealand, is one of the most important developments in insect pest control during the year, and gives great promise of the successful establishment of the parasite, and the subjection of the horntail borer in the Dominion.