They belong to the Curculionidae family, which is made up of more than 40,000 species. They have very hard bodies and are small in size. They prefer crops from the Solanaceae family, especially the Capsicum genus (peppers); they feed on this fruit, lay eggs, and complete their life cycle. They must be carefully and continuously monitored, given their ability to cause huge damage. When they are already present on the crop, the best approach is to monitor them during the cooler parts of the day, as this is when they are most active. Another recommendation is to inspect the ground as well as the flowers and immature fruit, since they throw themselves to the ground and keep still when they detect a threat.
Life cycle and appearance of Pepper weevil
Newly hatched adults have a light brown colour, with an oval body measuring 2 to 3.5 mm in length, and over time they turn grey, reddish-brown, or nearly black. Their main distinguishing feature is a ‘snout’ which is longer than their head and prothorax. Two days after hatching and feeding, they begin to copulate and subsequently lay eggs in the flowers or immature fruit. On average, a female weevil lays 341 eggs over the full oviposition period, which hatch after four days. The larvae are whitish and plump, with large black spots and brown mandibles. When they hatch inside an immature fruit, they move towards the middle of the mass of young seeds; whereas, when they hatch inside the flower bud, they feed on immature pollen. In both cases, they begin to feed one to four hours after hatching. In total, the larva passes through three larval stages during which its only activity is feeding; the larval stage lasts around seven to eight days, depending on the temperature. When pupation begins, the larva forms a cavity and covers it with its excrement, creating a type of cell, to be used later when it begins its metamorphosis. It develops a shiny white colour and eyes which are yellow at first, and become darker after a few days; after three to six days, this stage is fully complete and it becomes an adult. On average, the cycle takes 21 days.
The most significant damage occurs with the loss of fruit, whether they fall to the ground or contain holes where eggs are laid or adults were hatched. Meanwhile, the larvae develop in flower buds and young fruit, causing the stalk and calyx to turn yellow before wilting and dropping off. When you see fruit on the ground, it is clear that the crop has been very severely damaged.
How to get rid of Pepper weevil
Koppert offers different solutions for biological pest control of Pepper weevil.