Vegetable growers in New South Wales have developed a new form of biological control to protect their crops from the heliothis moth pest.

The moth costs the sweet corn industry millions of dollars every year by damaging the corncobs, but now the farmers are fighting back, with wasps. 

Research conducted at Bathurst, Windsor, Dubbo and Cowra has shown that two species of parasitoid wasps will prove particularly effective in reducing the number of moths. Female wasps lay their eggs inside heliothis eggs, and then the wasp larvae eats the moth larvae when it hatches. Researchers hope that by introducing wasps, the moth population can be reduced by 90%.

Agriculture horticulturalist Clarrie Beckingham participated in the Bathurst trials, and believes that wasps are highly effective when used in conjunction with insect friendly bio-pesticides. Farmers will have to make the environment suitable for wasps, however, says Beckingham. “Given good management, the right food sources and microclimates that encourage the wasps, levels of egg deaths above 70 per cent can be achieved,” he explained.

Beckingham added that for those wishing to control the heliothis population, crop monitoring and measuring egg parasitism are also important.