A Review on Papaya Mealybug Identification and Management through Plant Essential Oils

Abstract

Papaya (Carica papaya L.) production suffers from a multitude of abiotic and biotic constraints, among those are insect pests, diseases, and environmental conditions. One of the seriously damaging pests of papaya is invasive papaya mealybug, Paracoccus marginatus, which can inflict heavy yield loss if not contained. Little information on papaya mealybug species has been documented due to challenges in identification approaches to species level. The current approach is based on the morphological features which are restricted to the mealybug life cycle leading to unclear identification. In Sub-Saharan Africa, where a wide diversity of mealybug species exists, it is essential to have a correct identification of these insect species due to the specificity of control measures. Molecular identification could be the best way to identify the mealybug at the species level. Presently, farmers rely heavily on chemical pesticides as their only available option for papaya mealybug control. The overuse of pesticides due to insect waxy covering has led to the development of pesticide resistance and the negative impact on the local ecosystem. Alternatively, the use of plant essential oils (EOs) with adjuvant is suggested as the safe solution to papaya mealybug control as they contain a rich source of natural chemicals that dissolve the insect wax layer, causing the cell membrane to rupture eventually leading to death. This review provides current research knowledge about the papaya mealybug identification approaches and plant EOs from Sweet orange, garlic, castor, and adjuvant (isopropyl alcohol, and paraffin) as sustainable papaya mealybug management.