THE HORNTAIL BORER

Evening Post, Volume CXIV, Issue 90, 13 October 1932, Page 11

THE HORNTAIL BORER

DAMAGE TO PINE TEEES

EXPERIMENT WITH PARASITE

(By Telegraph.—Press Association.) ; NELSON, 12th October. 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 steel blue horntail borer, which is now well established in the Dominion. Though the borer does not damage vigorous trees, it is much too common to be discarded aB of minor importance. A parasite 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 Eoyal Parasite Laboratory for tlio parasite to be studied and supplies 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 fronr one country to another and establish it in a new environment. Several consignments of the parasite 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 the Cawthron Institute, i • PROMISE OF SUCCESS. That there was Borne 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 the bark and laying its eggs on the boring grubs. However, whether this had been successfully1 accomplished or not could not be practicably ascertained, the, parasitised borer being concealed within the timber. In consequence a careful watch was kept' fortjie emergence, of adult parasites from the 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 Cawthron Institute, and there is every reason to . expect that the same is taking place in the plantations at Blenheim, Hanmer, and Mouterei The appearance of this first generation of the parasite to be reared in New Zealand is one of the most important developments in insect pest control during the year, and gives j great promise of successful establishment of the parasite and the subjection of the horntail borer in the Dominion.