Chilocorus cacti as biological control agent of the wild cochineal of the cactus pear

Abstract

The hemipter Dactylopius opuntiae (known as wild cochineal) is the main pest in plantations of
nopal (Opuntia spp.). In Mexico there are restrictions on the use of insecticides in these crops.
For this reason in this work, the capacity of the coccinellid Chilocorus cacti (that in larva and
adult state consumes cochineal), was evaluated experimentally to be used as a biological control
agent. It was found that the silk that covers the body of the adult cochineal limits the C. cacti
consumption. However, in 60 days, and in stems with high levels of infestation, the presence
of C. cacti reduced the survival of cochineal more than 50%. The reproduction of C. cacti, and
the development of its larvae, increased nine times the number of individuals with predation
capacity, which increased the risk of mortality of the cochineal. Although silk restricts the consumption
of adult cochineal, C. cacti significantly reduces the density of D. opuntiae