The use of cyclodiene insecticides as liquid seed dressings to control bean fly (Melanagromyza phaseoli) in species of Phaseolus and Vigna marina in south-eastern Queensland

Abstract

Dressing the seed of Phaseolus spp. and Vigna marina with aldrin, dieldrin, or endrin at 1 or 2 grams active ingredient per pound of seed, effectively controlled bean fly during the establishment period. Telodrin was also promising and warrants further testing. Endrin was more efficient than the other insecticides in reducing infestation and loss of plants by bean fly. However, yields from endrin-treated plants, with the exception of P. vulgaris, were no higher than from plants treated with the other insecticides. Endrin reduced establishment, and yield of P. aurem drastically. All species tested were susceptible to bean fly attack. P. vulgaris, P. atropurpureus c.v. Siratro, and P. latbyroides were more susceptible than P. aureus and V. marina. Seed dressing increased plant survival and yield, especially of the more susceptible species. Additional increases in yield were obtained from P. lathyroides by increasing the sowing rate of dressed seed. Dressing the seed of P. laibyroides with dieldrin or Telodrin five months before sowing did not reduce seed viability or insecticidal activity. Nodulation of P. lathyroides in sterile sand culture was delayed, but not prevented, by dressing the seed with dieldrin. In the field, no such delay was noted. Crown nodulation was reduced but the effect on the plants was small compared with the adverse effects of bean fly infestation. Low phytotoxicity and efficient control at low dosages favours the use of dieldrin against bean fly in all species tested except P. vulgaris, the seed of which is better treated with endrin.