Predatory potential of eleven native Moroccan adult ladybird species on different stages of Dactylopius opuntiae (Cockerell) (Hemiptera: Dactylopiidae)

Dactylopius opuntiae is an insect pest of cactus which is currently causing severe damage to cactus crops in Morocco. It was first observed in 2014 in the Sidi Bennour region 120 km northwest of Marrakech, and has spread very quickly to destroy the prickly pear cactus crops (Opuntia ficus‐indica (L.) Miller) in several regions of country, causing very heavy economic losses. To control this pest, the predatory potential of eleven species of native Moroccan ladybird predators was investigated under laboratory conditions at 26 ± 2°C, 60 ± 10% RH and a 12 h light:12 h dark regime. The experiments were conducted in no‐choice feeding tests (only eggs, first instar or second instar of mealybugs were offered at one time) and free‐choice feeding tests (eggs and first and second instar larvae were offered simultaneously). In the no‐choice feeding tests, Exochomus nigripennis, Chilocorus bipustulatus and Chilocorus politus consumed the highest mean number of mealybug eggs and first instars, and the highest mean number of second instars was consumed by Hippodamia convergens. In the free‐choice feeding tests the highest mean number of mealybug eggs was eaten by Chilocorus bipustulatus and Chilocorus politus and Hippodamia convergens consumed the highest mean number of first and second instars of the mealybug.