Mango pulp weevil

Taxonomic position. The mango pulp weevil (Sternochetus frigidus) belongs to the order Coleoptera and the family Curculionidae. It is a highly specialized insect pest that causes severe damage to mango production, particularly in tropical regions of Southeast Asia, where it is considered a quarantine pest.

Host plants and damage symptoms. The primary host is the mango tree (Mangifera indica). The adult female oviposits on the surface of young mango fruits. Upon hatching, the larvae bore into the pulp and seeds of the fruit. This feeding activity creates internal galleries, leading to the decay of the fruit and premature fruit drop, which significantly reduces the marketable yield.

Biology and life cycle. The entire developmental cycle of Sternochetus frigidus occurs inside the mango fruit. The larva undergoes several instars before pupating within the fruit. The adult weevil then bores an exit hole to emerge. The cycle is highly synchronized with the fruiting phenology of the mango trees, allowing the pest to persist successfully in orchards throughout the year.

Economic impact. The weevil is a major concern for mango growers because damage is often internal and invisible from the outside until it is too late. High infestation levels can destroy almost an entire harvest, leading to significant financial losses and stringent export restrictions imposed by importing countries to prevent the spread of the insect.

Control measures. Integrated Pest Management (IPM) is essential for controlling this weevil:

• Strict orchard sanitation, including the prompt removal and destruction of fallen and infested fruits.
• Application of selective insecticides at the fruit-setting stage to prevent egg-laying by adult females.
• Monitoring populations using pheromone traps to time the application of control measures.
• Maintaining healthy trees through proper fertilization and pruning to increase natural resistance and ease of pest monitoring.