First study of the biology of Cryptolaemus montrouzieri and its potential to feed on the mealybug Dactylopius opuntiae (Hemiptera: Dactylopiidae) under laboratory conditions in Morocco

Dactylopius opuntiae, is known as specific Opuntia cochineal in many countries around the world. This sap-sucking insect was first detected in Morocco in 2014. To address the problem, the feeding potential of different development stages of Cryptolaemus montrouzieri Mulsant, a biological control agent against mealybugs, was investigated on different development stages of D. opuntiae. Fourth instar larvae and adults of C. montrouzieri were the most voracious feeders on different instars of the mealybug. The numbers of mealybug eggs consumed by first, second, third and fourth instar larva and adults of C. montrouzieri were 36.18 ± 1.84, 68.08 ± 4.17, 280.55 ± 5.41, 540.55 ± 5.35, 6514.13 ± 64.28, respectively. The numbers of mealybug nymphs consumed by the same stages of C. montrouzieri were 35.43 ± 1.75, 67.73 ± 3.88, 279.85 ± 5.58, 539.63 ± 5.08 and 6501.7 ± 81.94 (first instars) and 34.83 ± 1.20, 57.45 ± 1.22, 83.80 ± 1.92, 213.65 ± 3.46 and 6013.23 ± 35.46 (second instars), respectively. The corresponding figures for adult female mealybugs were 1.40 ± 0.78, 10.65 ± 1.83, 18.58 ± 1.24, 25.23 ± 1.10 and 197.15 ± 3.29, respectively. The egg, larval, prepupal, pupal and adult stages occupied 3.36–3.69, 20.21–27.59, 1.31–1.59, 10.62–10.72 and 96.10–102.51 days, respectively when the coccinellid was reared on different stages of D. opuntiae. The results indicate that C. montrouzieri has the potential to be used as a biocontrol agent in Morocco.