Efficacy of pymetrozine against Myzus persicae and in reducing potato virus Y transmission on tobacco plants

Abstract

Forty‐four parthenogenetic lineages of Myzus persicae s.l. (Sulzer) from tobacco crops and peach orchards located in various regions of Greece were examined to determine their response to the insecticide pymetrozine using leaf‐dip bio‐assays. The results show that the aphid has not developed resistance, as all lineages exhibited resistance factors bellow 6.0. In transmission experiments of potato virus Y (PVY) using a lineage of the tobacco‐adapted subspecies M. persicae nicotianae Blackman on tobacco plants, one foliar application with pymetrozine provided adequate protection for 7 days. Pymetrozine significantly reduced both virus acquisition and inoculation compared with the untreated control and the reduction was comparable to a mineral oil application. These results are discussed in terms of the advantage of incorporating pymetrozine as a compound of pest management strategies against M. persicae s.l. and for control of non‐persistent viruses, especially in crops such as tobacco because of the high selection pressure from neonicotinoids resulting in potential of resistance developing in aphid populations.

Biological performances of alfalfa treated with mineral oil Akarzin and reduced doses of insecticide

“…A similar protective effect of mineral oils in suppressing the transmission of different viruses was reported by a number of researchers [POWELL et al, 1998;MARGARITOPOULOS et al, 2009;SURANYI, 2010] .…”

“…In addition to the positive manifestations of mineral oils, there were studies which have established a synergistic effect when combining mineral oils with insecticides [AL-MRABEH et al, 2010] , protection of plants from different viruses by suppressing their transmission [POWELL et al, 1998;SURANYI, 2010;MARGARITOPOULOS et al, 2009] and lower toxicity of the oils in regard to the beneficial entomofauna compared with other pesticides [MCLAREN et al, 2008] .…”

Evolution of imidacloprid resistance in Myzus persicae in Greece and susceptibility data for spirotetramat

“…This way both insecticide groups may continue being effective for longer. In addition, pymetrozine, a pyridine azomethine, which causes irreversible cessation of feeding, could be used as another alternative to neonicotinoids as it has a completely different MoA (IRAC MoA group 9B) and there have been no reports of resistance in Greek and European populations of M. persicae . In crops that suffer from aphid‐transmitted plant‐viruses pymetrozine could be a valuable alternative, as it significantly reduces virus transmission …”

Behavioural avoidance and enhanced dispersal in neonicotinoid-resistant Myzus persicae (Sulzer)

“…The inoculation of non‐persistent viruses is associated with salivation during brief cell punctures by the stylets while that of persistent viruses is thought to occur during phloem salivation . Previous studies have often shown the application of insecticides to be beneficial in reducing the spread of plant viruses . From this study it appears that M. persicae disperses at the same rate regardless of the presence or absence of neonicotinoid treatment, hence in theory, the application of neonicotinoids should exert either a beneficial (due to increased vector mortality) or else no effect on the rates at which plant viruses spread within a crop, supporting such findings.…”