WHITE BUTTERFLY PEST

New Zealand Herald, Volume LXXII, Issue 22004, 10 January 1935, Page 11

WHITE BUTTERFLY PEST

CAMPAIGN OF DESTRUCTION

GOOD RESULTS ACHIEVED

Considerable success in combating the white butterfly pest in the Auckland district by means of the parasite insects propagated at the Otahuhu lechnical High School is indicated "in reports and observations made during the past few weeks. At the suggestion of the High School agricultural instructor, Dr. W. S. Hill, the school committee last year provided l'unds for the erection of a glass-house and the purchase of equipment for the rearing of these parasites. The local bodies in the Manukau district also made contributions toward the funds. The first liberation of parasites was made early in November, when 500 of the tiny flies were released in the neighbourhood of the school. 1« urther liberations were made subsequently at short intervals, and altogether about 3000 parasites have been reared at the school and released over a wide district. The district covered to date extends from Clevedon to Ellerslie and Pannjure. Considerable numbers have been liberated in the Panmure district, where market gardening is extensively carried on, and would, ordinarily, be a breeding place for white butterflies. Reports have been received from observers in many parts of the district and these indicate that tbore are fewer butterflies in evidence so far this season. At this time last year the pests were stated to be verv numerous throughout the Manukau district, and market gardeners and amateur horticulturists reported considerable losses in cabbages and other crops. Probablv the most, reliable evidence or the success of the campaign lies m tho fact that very small supplies of butterilv chrysalids are now being received at the propagation station at the Utahuhu High School. The chrysalids are the breeding places of the parasites, and once the tinv flies infect the pupae they die. In spite of numerous appeals to gardeners over a wide area for supplies of live chrvsalids to continue the propagation work there is a distinct dearth of simnlv. This is considered to indicate that the released parasites are successfully combating the pest. In an experimental cabbage plot planted at tho lligii School only a few live chrysalids have been collected during the past month.