In 1991, Wayne Teel in Mozambique asked about controlling cassava mealybug (Phenacoccus manihoti) without commercial insecticides. The mealybug can destroy up to 80% of the cassava crop.
Natural Crop Protection by Gaby Stoll (see EDN 50-8) says that cow urine is used against mealy bugs, thrips, mites, and other insects in Sri Lanka. Cows are penned overnight on a concrete floor which slopes to a tank. Collected urine stands exposed to sun for 2 weeks, then is diluted with 1 to 6 parts water and applied to plants. Tender vegetables require a more dilute urine solution than fully grown trees, as too concentrated a solution can burn the leaves. Test dilutions on different plants.
The 1995 World Food Prize was awarded to Dr. Hans Herren for his successful efforts in finding and implementing the biological control of the cassava mealybug in Africa. Based at Nigeria’s International Institute of Tropical Agriculture, Dr. Herren coordinated the worldwide collaboration (1979-1992) which resulted in mealybug control in 95% of the cassava-growing zones of Africa. Researchers found natural enemies in the pest’s South American home, and tested them in Africa. The most successful was the parasitic wasp Epidinocarsis lopezi, which was released in Nigeria in 1981. This wasp has been dispersed and established throughout Africa. We hope it has reached Mozambique by now.