Prickly pears, invasive insects and a battle Cyprus may not win

Changes in Cyprus’ landscape often happen gradually. A plant that once appeared healthy begins to weaken. A familiar patch of countryside looks slightly different from one year to the next. By the time the damage becomes obvious, the process behind it is often well advanced. One of the clearest examples is the spread of the prickly pear cochineal, Dactylopius opuntiae, an invasive insect that feeds on prickly pear cacti (Opuntia species) and has steadily expanded its presence across Cyprus over the past decade. The insect was first confirmed in September 2016 on prickly pear plants in the Famagusta district. According to the agriculture ministry, it has since spread into Larnaca district as well as parts of Nicosia and Limassol, causing severe damage to prickly pear populations. However, nearly 10 years after its arrival, important questions remain unanswered. How far has the insect spread in the past two years? Have control measures slowed its advance? Or is Cyprus ultimately facing a situation in which the pest becomes established across the entire island? According to Lyssandros Lyssandrides, senior agricultural officer and head of the plant protection at the agriculture ministry, this scale insect presents an unusually difficult challenge. The first reason is Cyprus’ climate, which provides favourable conditions for the pest’s survival and reproduction. A second challenge is the widespread presence of unmanaged prickly pear plants throughout the countryside. Individual plants and small clusters effectively act as stepping stones, allowing the insect to move gradually from one area to another. A prickly pear cactus destroyed by the mealy bug “Because these plants are not cultivated or cared for, they become easy reservoirs for infestation,” Lyssandrides said. The insect also possesses several natural defence mechanisms. It produces a waxy, cotton-like coating that significantly reduces the effectiveness of insecticides. At the same time, it secretes carminic acid, a red toxic substance that limits the effectiveness of many natural predators that would normally help control scale insect populations. Adding to the challenge, many highly toxic insecticides that might have overcome these defences have been withdrawn from the European Union market. For these reasons, the agriculture ministry has adopted what it describes as a “slow-the-spread” strategy rather than attempting complete eradication. The goal is to delay the insect’s advance long enough for native predators to adapt, for a natural ecological balance to develop, or for more effective long-term control measures to emerge. To achieve this, the ministry recommends avoiding the transfer of plant material and fruits from affected areas, regularly pruning plants to improve airflow and light penetration, and removing and burying infected cladodes. Officials also recommend washing infestations with strong water sprays. When combined with soap or alcohol, the treatment helps break down the insect’s protective wax coating and can be particularly effective when applied repeatedly. The ministry emphasises that these preventative measures remain the most important tool available. Without them, both chemical and biological control efforts are unlikely to succeed. Researchers are also investigating longer-term solutions. A healthy prickly pear cactus with ripe fruit (Depositphotos) One area of research involves identifying Opuntia varieties growing in Cyprus that show natural tolerance to infestation. Different prickly pear specimens have been collected from around the island for evaluation. Another avenue is biological control. The department is examining the possibility of introducing the predatory beetle Hyperaspis trifurcata in infestation hotspots. The beetle is one of the few known natural enemies that feeds almost exclusively on Dactylopius species. The story is made more complex by the fact that neither the insect nor the plant it attacks is native to Cyprus. The prickly pear cochineal originates in the Americas, where it evolved alongside cactus species of the Opuntia (prickly pear) family. Like many invasive pests, it is believed to have spread internationally through the movement of infested plant material. The prickly pear itself also arrived from the Americas. Native to Mexico, it was introduced to Cyprus in the late nineteenth century and gradually became a familiar feature of the island’s rural landscape. Today, prickly pear fruit remains a popular seasonal food. Consumed in moderation, it is often considered a nutritional “superfood” because it contains fibre, antioxidants, vitamins and minerals associated with various health benefits. What is now unfolding is therefore an ecological paradox: an introduced insect threatening an introduced plant that has become deeply embedded in Cyprus’ countryside. Yet despite nearly a decade of management efforts, the key question remains unresolved. The agriculture ministry continues to focus on slowing the insect’s spread, but it has not publicly indicated whether these measures are reducing infestations or simply delaying further expansion. Without updated data on the pest’s current distribution compared with previous years, it remains unclear whether Cyprus is winning the battle against the prickly pear cochineal or merely buying time before the insect reaches even more of the island.