Suppression of Helicoverpa spp. (Lepidoptera: Noctuidae) Oviposition by Use of the Natural Enemy Food Supplement Envirofeast®

The deterrent activity of a newly developed food product, EnvirofeasP and three other food sprays, sugar, Envirofeast 2 and petroleum oil plus Kelgum mixture, on oviposition by Helicoverpu spp. on cotton crops was investigated by mesh house choice and no-choice tests and large scale field trials at the Australian Cotton Research Institute at Narrabri, Norwood near Moree and Alcheringa near Boggabilla in New South Wales from 1992-95. EnvirofeastO treated plants received significantly fewer eggs than did any other treatment and water-sprayed (control) plants, both in the mesh house choice and no-choice tests and in field plots sprayed at 2-weekly intervals and exposed to natural populations of Helicoverpu spp. The deterrent effect on oviposition by EnvirofeastO spray in the mesh house was greater on H. punctigeru than H. urmigeru, but this effect was partially offset by increased H. urmigeru infestations in the field. This was evident during the 1992-93 and 1993-94 field trials at Norwood when the number of eggs laid on EnvirofeastO treated plots was significantly lower than any other treatments tested up to the peak of oviposition in February when the moth populations were dominantly H. urmigeru. Despite the species difference in response, the study demonstrates oviposition deterrence by the EnvirofeastO of Helicoverpu spp. on cotton and this indicates that Envirofeastm may be used in an integrated approach in cotton systems to reduce Helicoverpu spp. numbers. This effect could modify the predator to prey ratios so as to enhance levels of biological control.