The Aristobia recticulator which is devouring trees in large number.
Scientists have found evidence of China beetles or the Chinese stem borer beetles infesting gooseberry or amla plants. This is taking place in Arunachal Pradesh. The infestation spreading rapidly.
A study was conducted by entomologist Dr MM Kumawat and his colleagues from the College of Horticulture and Forestry (CHF) and Central Agricultural University, Pasighat, Arunachal Pradesh. They found a severe infestation of Aristobia recticulator on amla plants in East Siang district. The study was carried out in 15 orchards in the plain areas. It was done on 287 trees between 4 to 15 years old. Of which 58.9% were damaged.
The study has been published in the latest edition of the Indian Journal of Entomology.
In his research paper, he noted that the Chinese beetles were found feeding on the bark of tender twigs. This causes girdling during the summer months from June to August. The China beetle was observed with varying levels of infestation.
Maximum China beetles were observed in the weakened trees. It also leads to the decline of orchards. Most of the beetles preferred to lay eggs on earlier injured plants. Further, more than one larvae were found on a single host. Beetles preferred to lay eggs on litchi, followed by gooseberry, whereas guava was the least preferred host for egg laying as reported by scientists.
The beetle is a regular pest of litchi and longan trees in China and Myanmar. Since the beetles have now moved to amla trees as well, this causes a further danger.
He further said the beetles may also invade the neighbouring Assam.
Dr L Wangchu, Associate Professor at CHF stated the pest migrated from China and Myanmar to the northeastern states. This occurred due to geographical proximity.
Dr Wangchu added that it is a major threat to litchi and amla growing states. Such as Bihar, West Bengal, Uttar Pradesh and Jharkhand. The spread can be increased if quarantine measures are not taken.
Considering this threat, entomologists are conducting extensive research on incidence and bionomics of the China beetle.
Studies have revealed that old fruit trees are severely damaged by the China stem borer beetle. They had left numerous larvae on a single tree-tunnel. The shoots or branches of 36.1% of the infected trees died. This was caused due to heavy tunnelling by the beetles in xylem tissues.
Dr Kumawat said a further study on the China beetle is important as this may damage forest trees in the states. It also poses a threat to the plant ecosystem. He observed that complex geography and natural factors support rich entomological fauna. This enables the Aristobia recticulator for better survival in the natural forests of the Himalayan region.