Biological control of the prickly pear cochineal Dactylopius opuntiae Cockerell (Hemiptera: Dactylopiidae)

Abstract

The prickly pear cochineal Dactylopius opuntiae Cockerell (Hemiptera: Dactylopiidae) is a serious pest that causes severe damage to prickly pear cactus species of the genus Opuntia. Before its introduction to Morocco no control methods were available for use against this pest. The current paper presents the results of the use for the first time of the mealybug destroyer Cryptolaemus montrouzieri Mulsant (Coleoptera: Coccinellidae) and the biopesticide d‐limonene to control D. opuntiae. The efficacy of the biopesticide was evaluated under field conditions. Corrected female mortality rates were >82% 6 days after application of d‐limonene at 60 ppm. The greatest mortality rates 6 days after treatment were 98% and 99% at 120 and 150 ppm, respectively. The data analysis showed that there was no significant difference between the different doses 6 or 13 days after treatment. The LD50 recorded was 33 ppm. In terms of biological control, the use of Cryptolaemus montrouzieri significantly reduced the cochineal scale population by 92% 77 days after release. This effect was maintained until 99 days after release of C. montrouzieri, and then the rate of population reduction declined to the level observed 64 days after release (66%). These results suggest that C. montrouzieri has the potential to suppress D. opuntiae populations to an acceptable level and reduce the damage caused by this cochineal.

Dactylopius opuntiae, a new prickly pear cactus pest in the Mediterranean: an overview

“…The environmental conditions and the availability of the host plants also seem to be favorable for the survival and development of the false carmine cochineal, which has become highly noxious to the prickly pear cultivation. The recent rapid infestation in Israel and Morocco requires control measures (Bouharroud et al., , ; Protasov et al., ; Mendel et al., ).…”

“…In northern Israel, inundative releases of C. montrouzieri (about 100 000 individuals) were unsuccessful in managing the early outbreak of the wild cochineal (Protasov et al., ) although along the coast, local acclimated populations of this beetle began to reduce the cochineal populations (Mendel et al., ). In Morocco, the release of 30 C. montrouzieri adults per m 2 of ground surface, significantly reduced the cochineal population by 92% within 77 days after their release into areas where the minimum temperature exceeds 5 °C (Bouharroud et al., ).…”

“…(Lopes et al., ). In Morocco, d ‐limonene at 120 and 150 ppm showed the most toxic effect against adult females of D. opuntiae , although chlorotic damage to the cladodes was also observed (Bouharroud et al., ). It is interesting that the aqueous extract of D. opuntiae hemolymph was found to repel crawler fixation – this has good potential as a control measure due to its availability for farmers and the simple preparation procedure (Pérez‐Ramirez et al., ).…”

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

“…and Scymnus sp. have been consistently observed in association with colonies of D. opuntiae in many other countries where D. opuntiae is primarily a pest (Murali Baskaran et al, 1999;Adalma-Aguilera et al, 2005;Vanegas-Rico et al, 2010;Barbosa et al, 2014;Bouharroud et al, 2018). In addition, Khan et al (2012) reported that a combination of predators ensured varying degrees of success for control, both in fields and greenhouses.…”

Comparison of the efficacy of two insecticides for the management of Dactylopius opuntiae on prickly pear cactus in Lebanon and monitoring of the insecticides residues dissipation rates in fruits and cladodes

“…Orange oil provoked death of nymphs and adults within 48 h after treatment [5]. And, d-limonene from citrus juice was mostly efficacious against adult females and second instars but had little adverse impact on natural predators [7] and caused chlorotic damage to cladodes [10]. Nonetheless, for all of these, further researches are required on spraying coverage and impact speed of the droplets in order to optimize pest control on severely infested areas as is the case in Lebanon.…”