Cochineal of Cactus

Cochineal of Cactus

The cochineal called Dactylopius opuntiae is one of the most important pests that affect the prickly pear known in Tunisia by the name “Hindi”.  This latter appellation seems somewhat unusual at first but we can understand it if we know that the prickly pear is called Opuntia ficus-indica. Here, it does not mean the Asian India but the Occidental India of the American Indians since the origin center of the prickly pear is the south region of the North America, from which it was carried to and sprayed in Europe from the 16 th century, then toward many other regions of the world including particularly the North Africa and the Arab Mashreq. It should be noted the extreme importance of the prickly pear which can develop in the semi-arid and arid areas where it leaves for long time with the remarkable capability of resistance to drought due to their pads which store a lot of water and hence it plays an essential role in the desertification control and in the conservation of the biological diversity around it. The countryside inhabitants in many regions plant this culture as a barrier around their properties and benefit at the same time of its delicious fruit and its pads as animal feed. The fruit is also exploited in the industries of medicines, coloration and cosmetic. The cochineal of cactus is a Hemiptera, which attacks the prickly pear at the surface of the pads and fruits and generally settle as dispersed and various sized colonies, implanted at the foot of the spines. The damages are always caused by the adult females and the larvae whose bodies are oval to rounded, with dark purple color that becomes light red when crushed and this latter color is the typical carmine color of the insect. In contrast, the adult male causes no damages. The adult females and the larvae secrete filamentous white waxes that protect them as covering and allow them to move from one pad to another. The infested pads show yellowing areas which enlarge more and more leading ultimately to the fall down of attacked pads and the death of the trunk with 100% of damages when the affection is heavy. This pest exists presently in few regions of the world that are 9 countries: United States, Mexico, Australia, Ceylon, India, South Africa as well as the Palestinian Territories and Morocco since 2014 an recently Cyprus since 2016. Hence, it can be noted that the existence of the pest in Palestine and Cyprus threats the Mashreq Arab countries, whereas the arrival to Morocco of this insect is a high threat to the rest of the Maghreb countries regarding the geographical, economic and social continuity between these countries. The cochineal of cactus on the prickly pear in Morocco was firstly discovered late 2014 in the
Khemis-Zmamra region and early 2015 in the Sidi Bennour region in the zone of Doukkala-Abda and these regions are situated at the south of the Casablanca city where this pest had spread on a surface of 100 km ray in two years. The control of the cochineal of cactus infesting the prickly pear is a laborious work regarding the hard penetrating in the prickly pear cultures which are usually established on marginal, rugged and very extended lands. And according the current Moroccan experience, with the support and the advising of FAO, the control is a priori mainly based on the chemical method pending the development of other biological and cultural methods
and the selection of resistant or at least tolerant varieties to the pest. For this reason, Tunisian competent services of the ministry of agriculture should prepare well their capacity buildings of human, material and fund sources for this high threat because the spread of such pests and diseases occurs easily between neighboring countries and the examples are numerous as was the cases of the tomato miner, the red palm weevil, the pome fruit fire blight, etc. The issue is then very serious regarding the extreme importance of the culture of the prickly pear for a very large number of farmers and animal breeders and the dependence of subsistence resources of many
countryside inhabitants on this culture which provides human food an animal feed, in addition of the possibility of its transformation and industrialization. Tunisia is considered among the first countries of the world with regard to the prickly pear culture surface which is estimated to 600,000 ha whose the majority exist in the arid regions of the center of Tunisia, and it is crucial to
provide the maximum of effort to conserve these cultures and to protect them from all types of bioaggressors.

 [Dr. Bouzid Nasraoui, National Agronomic Institute of Tunisia University of Carthage, Tunis, Tunisia, September 2017]

Some observations on the cochineal scale insect of cactus (Dactylopius opuntiae) (Hemiptera: Dactylopiidae) in Morocco
The cochineal scale insect appears in Morocco for the first time in Saniet Bergig (Morocco) by the end of 2014. It attacks only cactus plants Opuntia sp. It is characterized by its red color because of the carmine secretion. The origin of these insects is tropical and subtropical forest of America and Mexico. It is soft insect with oval form. The males are winged in contrary of females, which are covered by white wax substance. The females lay eggs after copulation hatched in to small larvae secreting white waxy substance to protect
themselves from loss of water and heavy sunrays. The scale insect appears as white cotton-like piles, it moves into the marginal cactus pads, the wind carries the filament waxy substance into new cactus plants. The winged males are disturbing the human populations around the cactus fields. The food national office of Morocco confirms that the cactus fruits consumption do not have any health effect neither for human nor for animals. This scale insect affects cactus yields and causes enormous losses to the plants by sucking their sap lead to pad drought. The cactus plants die when the infestation is heavy. The prevention methods are the best solution to avoid
insect transmission and reducing damage. The transport of infested cactus pads and fruits should be prohibited. The plastic boxes are recommended to use instead of woody after washing and disinfecting. Controlling the vehicles are also playing a roll in insect transmission. The control measures should be applied for the disposal of infected plants and using the recommended
chemical control by ONSSA.
Abdelmoughit Ait Friha ,Provincial Service of Control and Plant Protection of Boulemane, www.onssa.gov.ma , 2016