Pink Hibiscus Mealybug Biological Control Programme in St. Kitts

The Pink Hibiscus Mealybug Maconellicoccus hirautus (Green) is an insect that lives in many tropical countries. It is a serious pest of many different fruits, vegetables, ornamental plants and trees. It appeared in St. Kitts in October 1995. On 02 August, 1996, an encrypted wasp Anagyrus kamali, an exotic pest of the Pink Hibiscus Mealybug Maconellicoccus hirautus (Green) collected and imported from China was released for the first time in St. Kitts. The releases totaled 3, 5000 individuals at eleven (11) different locations. Most parasites were released on infested hibiscus at residential properties. Additional parasites were released on wild cotton, sea grape and a wild Acacia spp. One month following the parasite releases, an average of 17% of the Pink Hibiscus Mealybug was found to be parasitized by Anagyrus kamali at seven different selected sites on St. Kitts. In November parasitization reached an average of 29.4% and in December, parasitization averaged 18.9 %. Anagyrus kamali alone reduced the mealybug population density up to 90% in a five month period (August – December 1996) on Hibiscus plants in St. Kitts Cryptolaemus montrouzieri Mulsant, a coccinelid (beetle) predator called the “mealybug destroyer” was successfully used as a biological pesticide to eliminate pesticide applications against the mealybug in St. Kitts and to avoid harsh residue impact on the establishing parasite. Hotels and restaurants properties that had extremely heavy Pink Hibiscus Mealybug populations were targeted for release of commercially produced Crytolaemus. montrouzieri. A total of over 145,000 adult beetles were released on more than 200 properties at a rate of approximately 200-500 beetles per property. Within a period of six to eight weeks, the predator significantly reduced the mealybug population density. Parasites were also released at selected site where Crytolaemus. montrouzieri was formerly released to maintain low mealybug population densities and help speed the parasite’s dispersal and establishment process. The exotic parasite Anagyrus kamali, has successfully reduced population densities of the Pink Hibiscus Mealybug permitting previously heavily infested hibiscus and other host plants to flower and thrive. A parasite complex is believed to be the long term solution to this pest problem.