THE WHITE BUTTERFLY.

Manawatu Standard, Volume LIII, Issue 25, 27 December 1932, Page 6

THE WHITE BUTTERFLY.

The liberation of a large number of predatory insects to prey on the white butterfly is the commencement of a campaign to rid the Dominion of a pest which has spread in alarming numbers over the North Island. First noted in parts of Hawke’s Bay in 193 U it has since appeared in districts to the north and south of that province. Last summer it was reported in ever growing numbers, and towards the autumn specimens were discovered in Balmerston Nortli and the surrounding district. The butterfly raids cruciferous crops, and the Department has chosen an area in the Hawke’s Bay where these are extensively grown to launch the first attack in its warfare. Other of the insects, which rejoice in the name of Apanteles glomeratis, a branch of the ichneumon family, will be liberated in a circle so as ts> converge on the main centre. These insects are a parasite and lay their eggs on the larva of the white butterfly on which the young prey. It is also to be noted that another species of parasite has been imported to attack the pest in its pupal stage. The progress of the measures will be watched with keen interest by farmers and market gardeners whose crops are susceptible to attack. In coiintries o’verseas, where the white butterfly has long been recognised as a pest, its control is effected in part by means of arsenical sprays, but though this would be possible in New Zealand gardens of limited area, it is not feasible where farmers’ crops of cruciferous plants cover acres of ground. It is believed that the butterfly was introduced to New Zealand among vegetables landed from Honolulu by a trading ship. This emphasises the difficulty of keeping the country free from foreign pests. The cost of the measures now being taken to destroy the butterfly, apart from the destruction it lias caused, emphasises the ever-present need to guard against the importation of destructive pests.