Predatory efficiency of six-spotted ladybird beetle, Cheilomenes sexmaculata (Fabricius) against the mixed prey densities: a functional response analysis

Functional response is the crucial factor in understanding the efficiency of coccinellid predators in managing the sucking insect pest species. The six-spotted ladybird beetle, Cheilomenes sexmaculata , is known to show a voracious appetite for prey species such as the whitefly, Bemisia tabaci , the papaya mealybug, Paracoccus marginatus , the cotton aphid, Aphis gossypii and the cotton mealybug, Phenacoccus solenopsis , which are devastating sucking pests of cotton. An experiment was conducted to understand the functional response of C. sexmaculata against mixed prey densities by using all four species as prey. Results showed that all the developmental stages of the predator displayed a type-II functional response. The first instar had the highest attack rate (à) according to Roger’s random equation and Holling’s disc Eq. (1.27 ± 0.12) and (0.82 ± 0.06), followed by the fourth instar grub (1.01 ± 0.05) and (0.67 ± 0.02), respectively. Using both equations, male and female, the third and fourth instar grubs had the lowest handling time (Th) (0.01 ± 0.00). Therefore, it can be suggested that the third and fourth instar grubs and adults of both sexes of C. sexmaculata could be employed for augmentative biological pest control programmes of this sucking pest complex in the cotton crop ecosystem as a sustainable pest management strategy.