Cochineals on cactus pear: a dilemma, pros and cons.

The cochineal insects, Dactylopius spp., (Hemiptera: Dactylopiidae) develop on members of the Cactaceae. Several Opuntia (cactus pear) spp. (Cactaceae) have gained much attention as highly valuable plants on the one hand, and as notoriously invasive weeds in different areas of the Globe on the other. Dactylopius coccus is the source of a precious carmine red dye and was the primary reason for introduction of cactus pears into different continents. Other Dactylopius spp., were employed as biological control agents against invasive Opuntia spp., mainly in the Southern Hemisphere. During the last decade D. opuntiae emerged as a pernicious pest of O. ficus-indica in various areas in the Mediterranean and D. coccus has become a major problem of this plant under cultivation in Ethiopia. The recent outbreaks pose a serious threat to the cactus pear industry in the Mediterranean Basin and Central Africa. The ultimate long-term solution to the problem is classical biological control by introduction of different predators of these cochineals from their indigenous areas. However, this approach may lead to a catastrophic event in Southern Africa whereby other Opuntia spp. may be released from the pressure by these scale insects and would reclaim again large areas of agriculture and grazing lands. This dilemma calls for a serious discussion at the international level. The idea is to achieve sustainable and environmentally friendly management of these Dactylopius spp., without jeopardizing the successful biological control of the invasive Opuntia spp. We discuss the foster need of interregional cooperation and coordination and the promotion of an open platform (https:// dgroups.org/fao/cactusnet/cochineal), with no restriction in regards to the kind of philosophies expressed. Any participation and contribution will be most welcome.