CROP PESTS

Wairarapa Times-Age, 19 March 1941, Page 7

CROP PESTS

WHITE BUTTERFLY PARASITE WELL SPREAD. INVESTIGATIONS REGARDING DIAMOND BACK MOTH. Although the white butterfly appears to be more in evidence in the past week or two than it has been for some time past, Mr N. Lamont, of the Department of Agriculture, Masterton, states that a close inspection of crops shows that the number of actual caterpillars of the diamond back moth vastly exceeds the number of white butterfly caterpillars. The white butterfly parasite is now generally distributed throughout the district, he states. Though it is to be expected that there may be periods in any season in which the butterfly may temporarily assert itself over the parasite this period should not last more than a few weeks at the outside. If the diamond back moth caterpillar was as conspicuous as that of the white caterpillar the crops would be smothered with them. The white butterfly, he states, has a definite preference for cabbages and cauliflowers but as regards soft turnips it would be safe to say that the diamond back does 99 per cent of the damage.

It is understood that the Department’s entomologist is experimenting in the field with parasites which it is hoped will assist in the control of the diamond back moth. The investigation is still proceeding and it is too early yet to ascertain what measure of success is likely to be obtained. Specimens of the two parasites being experimented with have been liberated in Hawke's Bay and both have since found their own wav to the Wairararapa.