Some effects of benomyl and carbendazim on Aphis fabae and Acyrthosiphon pisum on field bean (Vicia faba)

Abstract

S U M M A R YField bean plants were treated with benomyl in a glasshouse, then nymphs of Aphis fabae and Acyrthosiphon pisum were caged on the second pinnate leaf. Soil drenches at concentrations of 150 and 75 pg benomyl/ml or above increased mortality of A. fabae and A. pisum respectively; 250 pg a.i./ml increased mortality and decreased progeny production of alate A. fabae. The effect on mortality persisted for at least 16 days after treatment. Foliar sprays increased mortality at concentrations of 75 pg a.i./ml and above (A. fabae). Field populations of A. pisum were reduced when bean plants were drenched or sprayed at a concentration of 250 pg a.i./ml and A. fabae populations were reduced by drenches but not by foliar sprays. A commercial formulation of carbendazim (Bavistin) increased aphid mortality whereas the formulation medium did not. Under the experimental conditions, benomyl affected the distribution of both species on young bean plants but did not induce a repellent effect; aphids preferred untreated leaves. Mortality and preference tests, and a field experiment, indicated that A. pisum was affected more than A. fabae.

The toxicity of some benzimidazole fungicides to the pea aphid, Acyrthosiphon pisum

“…The quantitative relationship between the mortality of A. pisum and A. fabae and the concentration of benomyl applied as a drench to field beans reported by Bailiss et al (1978) was confirmed and extended in the present study for A . pisum on field bean in terms of endogenous MBC content.…”

“…There was a clear association between aphid mortality and the MBC content of the leaves on which the aphids had fed. The lower MBC content in leaves of sprayed compared with drenched plants may explain why Bailiss et al (1978) found the mortality of A . pisum and A .…”

“…It has been shown that the mortality of A . pisum on field bean following 'Benlate' sprays increased with the concentration of the fungicide applied (Bailiss et al, 1978). The relationship between the concentration of 'Benlate' sprayed on to batches of 10 plants and MBC content 6 days after spraying is shown in Table 2.…”

“…As with 'Bedate'-drenched The persistence of MCB in leaf 2 and young leaves was next tested as it had previously been shown that benomyl treatment induced aphid mortality 16 to 21 days after the second drench and affected the distribution of A . pisum on young bean plants (Bailiss et al, 1978). Unfolded leaf 2 leaflets and young folded bean leaves were sampled 1, 8, 15, 22 and 29 days after the second 'Benlate' drench.…”

The effect of benomyl on some invertebrate inhabitants of a red raspberry, Rubus idaeus, plantation in relation to fruit yield

“…in raspberry plantations (Anon., 1978). In addition to its fungicidal properties benomyl deters aphid feeding (Thomas & Bradley, 1975;Sagenmuller, 1977;Vickerman, 1977) as well as being toxic to aphids (Wilding, 1972;Vickerman, 1977; Bailiss, Partis, Hodgson & Stone, 1978), mites (Delp & Klopping, 1968;Dicker, Gambrill & Easterbrook, 1972), nematodes (Trudgill, 1975) and earthworms (Cook & Swait, 1975;Wright, 1977) and it also has kinin-like activity (Skene, 1972; Thomas, 1974).…”