What is Stone Weevil?
Stone Weevil is a monophagous pest which infests the seed or stone of the fruit.
Scientific Name – Aubeus himalayanus Voss
Life Cycle-
Egg: The adults lay their egg mostly on the stylar end by puncturing the fruit. The punctured hole is thus cover with brown encrustation.
Grub: The grubs are white in colour with red marking on the body, which are present inside the seeds. The pupation takes place in the seed itself.
Adult: The adult weevils are small dark in colour with snouts. The activity of adult weevil could be observed in the field during morning and evening hours.
How does Stone Weevil damage?
- The adult lay their egg in mature fruit by puncturing it. The Grubs after hatching moves inside the seed by puncturing endocarp at immature stage and starts feeding on soft seed coat. Later it enters into endosperm moving downward. After entering the seed, it starts feeding on inner content of the seed, and pupates within the seed by making hallow galleries.
- The grub thus destroys the developing soft seed completely after feeding on it. At maturity when the fruits are harvested the grub or pupa can be seen in the fruits making it unmarketable.
- The weevil completes its life within a single fruit.
- Infested fruits have abnormal shape and fruits towards stalk turns reddish brown with rough surface. Infested fruits fail to attain full maturity. The infestation can be seen throughout all the developmental phase of the fruit.
How to manage Stone Weevil-
| Cultural Practices | Chemical Control |
| The pest feeds only on the seed portion of developing fruits and arrest further development of attacked fruit. The entry hole is healed up and closed while the exit hole can be clearly seen. Collection and destruction of adult weevil immediately after detection can also reduce the population. Infested dropped fruits should be collected and burned to break the generation cycle. | Foliar Spray of –Chloropyriphos 50% EC + Cypermethrin 5% EC @1 ml/litre. Profenophos 40% + Cypermethrin 4% EC @2 ml/litre. Spinosad 45% SC @ 0.4 ml/litre. |
References: –
- https://ppqs.gov.in/sites/default/files/ber.pdf
- https://krishi.icar.gov.in/jspui/bitstream/123456789/3653/1/stone%20weevil%20aubeus%20on%20ber.pdf
- https://image.slidesharecdn.com/ento331l21pestsofsapotabercashew-240417133903-9307358d/75/ENTO-331-L-21-Pests-of-Sapota-Ber-Cashew-pptx-8-2048.jpg
