Biology and functional response of Oenopia sauzeti (Mulsant) on peach leaf curl aphid, Brachycaudus helichrysi (Kaltenbach)

Abstract

Brachycaudus helichrysi, also known as peach leaf curl aphid is a destructive pest that poses a grave threat to peach and nectarine cultivation. The existing management practices primarily rely on applying synthetic insecticides whose indiscriminate use has led to a myriad of problems. To address these issues, biological control agents like ladybirds (Oenopia sauzeti) have emerged as an environment friendly alternative strategy. Till now, there has been a dearth of precise information on the biology, fecundity as well as functional response of O. sauzeti against B. helichrysi. The present study assesses the demographic parameters and functional response of O. sauzeti preying on B. helichrysi under laboratory conditions at 25 ± 1 °C, 70 ± 5% RH and 12 L: 12 D photoperiod and aims to provide valuable insights for its potential use in pest management. The findings showed a net reproductive rate, gross reproductive rate, true generation time and intrinsic rate of increase of 59.92 females/predator, 76.95 offspring per individual, 33.36 days and 0.12, respectively. The results showed that O. sauzeti exhibited a type II functional response. The highest predation rate was observed in the adults (78.21), which was significantly different from 1^st, 2^nd, 3^rd and 4^th larval instars (19.68, 32.30, 36.49 and 51.64, respectively) of the coccinellid. This research provides essential information for using O. sauzeti as a biocontrol agent for B. helichrysi and would prove beneficial to sustainable pest management strategies in stone fruit cultivation.