Molecular Identification of Mealybugs (Hemiptera: Pseudococcidae) on Cultivated, Ornamental and Wild Host Plants in Swaziland

Abstract

Mealybugs are considered as the most important insect pests of fruits, vegetables and cotton in Swaziland. However, lack of sound identification and information on the mealybug species attacking these crops in the country represents a major barrier to establish satisfactory pest management strategies. In this study, a DNA barcoding approach was used to identify mealybug species attacking wild hosts, ornamentals and cultivated crops in the country. Molecular identification using fragment of mitochondrial cytochrome oxidase sub-unit I revealed the presence of six mealybug species belonging to four genera. A significant (0.00-0.68%) within species similarity and between species sequence divergence (6.90-16.80%) was observed. Of the species identified Phenacoccus madeirensis and Phenacoccus solenopsis, were the dominant and were highly polyphagus. Phenacoccus solenopsis, was recorded from 12 host plants belonging to six families in three regions, whereas, P. madeirensis was recovered from five wild host plants growing in Middleveld regions. Other mealybug species collected were Saccharicoccus sacchari, Planococcus citri, Paracoccus burnerae and Phenacoccus solani. The study has validated the efficacy of sequence diversity in the COI gene for identifying mealybugs. This is the first DNA-based characterization of mealybugs from Swaziland and the findings will help in decision making while considering biological control programs.