Mexican Beetle Saving the Israeli Sabra

The Prickly pear cacti (“sabras”), which are found throughout Israel, are being threatened by a cochineal scale insect that attacks the plant. Northern Israel has been particularly hard hit by the pest, and if a solution is not found, it could spread to the rest of the country. Professor Zvi Mendel, an entomologist from the Agricultural Research Organization Volcani Center, is conducting groundbreaking research with the support KKL-JNF using a Mexican ladybug belonging to the genus Hyperaspis, a natural enemy of the cochineal scale, as an agent of biological pest control to eradicate the scale and save the sabra cactus.

Professor Mendel remembers how he first discovered the pest: “A friend of mine from an Upper Galilee kibbutz phoned and described a strange ailment that was killing the sabra cactuses in his garden. I asked him to cut a few leaves and send them to me. I was most surprised to see the scale insect, which I had not known to exist in our region”.

The pest turned out to be Dactylopius opuntiae, a cochineal scale insect that comes from Mexico. It apparently entered Israel from Lebanon about three years ago, and spread throughout the north of the country. It has already been seen in the Golan Heights, the Upper and Lower Galilee and the northern Kinneret. Infested prickly pears whiten, dry up and die. The Lebanese media have termed the phenomenon the “cotton disease”.

The presence of the scale insect is very obvious in many places in northern Israel, among them Afula. Haim Weingarten, a gardening supervisor in the municipality said: “We had prickly pears that were more than 50 years old, extending along a kilometer. None of them are left. Spraying was ineffective and we were forced to cut down the plants, seal them in bags and burn them, to prevent the scale from spreading. In all my many years as a gardener I have never seen anything like this”.

Not far from Afula, in the Arab village of Dehi, prickly pears also became infested. The cochineal scale does not discriminate between religions or cultures, and fighting it will require cooperation between all the residents of northern Israel. In Kibbutz Lehavot HaBashan in the Upper Galilee, a row of prickly pears that were planted as a hedge around a pomegranate grove, were infested with the scale and died.

“As a leading environmental organization, KKL-JNF invests heavily in research and development,” notes Chief Forester David Brand from the KKL-JNF Forestry Division. “We support some 70 applied research projects yearly, which provide us with the best methods to manage ecosystems. This knowledge keeps KKL-JNF at the forefront of science and technology and also allows us to provide aid to other countries, which face similar challenges”.

Brand emphasizes the experience that KKL-JNF has accumulated over the years in biological pest control and notes: “The sabra (prickly pear) is an Israeli symbol and our aim is to reduce the cochineal scale population. We are working with KKL Mexico and Mexican scientists who are familiar with the pest, to save the sabras”.

Indeed the sabra has become part of the Hebrew language. The fruit of the prickly pear, called “sabress” in colloquial Hebrew, characterizes the Israeli personality – prickly on the outside but sweet within. This, despite the fact that the plant comes from Mexico, where it provided a habitat for the cochineal scale insects, which were used to produce red dye, for thousands of years. The Spanish conquistadores spread the prickly pear around the world as a basis for the dye industry. It arrived to the Middle East about 400 years ago.

Professor Mendel illustrates how crushing the insects gets the reddish dye out of them and says: “The dye industry is gone, but the prickly pears survived thanks to their resistance to drought and difficult climatic conditions. Beyond its symbolism, the plant is important as an ornamental and as a hedge plant and its fruit are used by farmers and the public at large”.

About two years ago an attempt was made in Israel to eradicate the scale with a ladybug from Australia that was acclimatized in Israel many years ago, however the scale insect apparently disagrees with the Australian beetle. Treatment with insecticides, in addition to its high cost and environmental and health hazards, has also not always proven effective. The cochineal scales develop resistance to the pesticides, which then cease to affect them.

KKL-JNF invited Mexican experts to Israel, who visited the north and examined the phenomenon. They recommended using a Mexican ladybug, belonging to the genus Hyperaspis. KKL Mexico took on the task of coordinating matters with the relevant authorities in Mexico.

About a half a year ago, the long awaited shipment of ladybugs arrived. Several dozen have been in quarantine at the Plant Protection and Inspection Services of the Ministry of Agriculture and Rural Development at Bet Dagan. Various experiments are being conducted at the laboratories at the site to ensure that the ladybug feeds exclusively on the scale and to examine what effects the beetles might have on other plant and animal species. The ladybugs are also being reared in the lab to form “fighter divisions” that will attack the cochineal scale insects.

Avner Shapira from Moshav Margaliyot is one of the people awaiting the arrival of the ladybugs. “I planted some prickly pear cactuses about twenty years ago, which developed into a long, impressive hedge. We like picking the fruits and eating them. One day I noticed a white scale on the plant. I tried spraying pesticides but nothing helped”. Shapira points to the dying plants and concludes: “It is so sad that this is all that is left from the beautiful sabra hedges that were here”. But he will not lose hope and believes that with the help of the Mexican ladybug it will still be possible to save his beloved prickly pears.

The joint Israeli-Mexican venture to eradicate the scale has aroused widespread interest in many scientific communities and in places suffering from infestations throughout the world. There is already talk of cooperation with Ethiopia where prickly pears are grown for animal fodder. The cochineal scale has spread there, and if the Israeli initiative succeeds, the Ethiopians will try to implement it in their country as well.

Hopefully the Plant Protection and Inspection Services will issue the necessary permits in the coming weeks and dispersal of the ladybug in northern Israel will begin in order to save the dying prickly pears and prevent the cochineal scale from spreading southward.