The Mango Nut Weevil, Sternochaetus mangiferae, belonging to the Family Curculionidae of the Order Coleoptera, is native to tropical and subtropical regions of Asia. It is one of the most devastating pests of mango crops, causing significant economic losses in mango production worldwide.
Since the larvae feed on the fruit, the quality and quantity of the harvest are significantly reduced. To effectively manage this pest, it is important to understand its life cycle, its preferred habitats, and the best methods for controlling it. This article will provide an overview and discussion of the Mango Nut Weevil Pest in Mango crops, including its symptoms, identification techniques, and control.
Mango Nut Weevil Pest Management
Life Cycle of Mango Nut Weevil Pest in Mango Crop
The life cycle of the mango nut weevil pest has four stages. They are egg, grub, pupa, and adult. The adult weevils are active from May to September and can lay up to 300 eggs per female, which hatch in two to three weeks. The adults lay their eggs by making small cavities in the skin of the fruits and covering it again with a brownish exudate. The eggs will hatch into grubs within one week.
The grubs will feed on the seed kernel for up to three months, which is the primary damaging stage of the weevil; they undergo five instars, after which they pupate in the seed within the stone of the fruit and emerge as adults in another two weeks. The pupae are encased in a case made of waxy material and are dark brown. The female starts laying eggs within 3-4 days after mating, and the cycle starts all over again. The lifecycle is completed in 6-8 weeks.
Occurrence of Mango Nut Weevil Pest in Mango Crop
- Location of Mango Nut Weevil pest: This pest infests mango crops in India, Africa, China, Burma, Bangladesh, Sri Lanka, Thailand, Malaysia, Indonesia, the Philippines, Australia, Vietnam, and Hawaii.
- Host range: The mango nut weevil is a monophagous species that feed exclusively on mango fruits.
Factors Favoring the Population Increase of Mango Nut Weevil Pest in Mango Crop
- Pest adaptation – The mango nut weevil has adapted to the changing environmental conditions accompanying increasing global temperatures. It can survive in various climates and has become resistant to many insecticides.
- Lack of natural predators – The mango nut weevil has few natural predators, which allows the population to increase unchecked. Natural enemies, such as birds and insects alone, cannot control the population.
- Pest mobility – The mango nut weevil is an extremely mobile pest, capable of flying long distances for food. This mobility allows the pest to spread to new areas, increasing its population.