- Indian Entomologist
The outbreak of chilli thrips in Andhra Pradesh: A matter of great concern
Andhra Pradesh is the largest producer of chilli and contributes 38% to the total production in India. Guntur, Krishna, Prakasam and Kurnool are the major chilli producing districts and Guntur alone contributes to 15 % of total production in India. In Guntur, district chilli is being cultivated in an area of 70,000 ha but during 2021-22 the area under chilli cultivation is increased to 1,06,656 ha. Reasons for the increase of chilli area in Guntur District is the constant market price (Rs 10,000-15,000 per qt) for dry chilli and conversion of cotton area to chilli due to incidence of pink bollworm (https://horticulture.ap.nic.in/).
Group of scientists from Dr. Y.S.R. Horticultural University, Andhra Pradesh noticed Thrips parvispinus (Karny) incidence for the first time in important chilli growing mandals of Andhra Pradesh i.e Chilakaluripeta and Prathipadu (16.09N 80.16E and 16.16N 80.22E) during January 2021, subsequently in other major chilli growing mandals. Chilli crop was at the harvesting stage during that period. Later, in summer it was also observed in green chilli growing areas.
While observing the pest damage, scientists noticed that species causing damage is not a regular species occurring on chilli i.e., Scirtothrips dorsalis. The samples were sent to Rachana R. Remani, Scientist, ICAR-NBAIR, Bengaluru for further Identification. Preliminary identification report shows that it is a mixture of Thrips florum (Schmutz) and Thrips hawaiiensis (Morgan). Later it was found that the majority of sample contain Thrips parvispinus.
About Thrips parvispinus:
Thrips parvispinus is reported as an invasive pest in 2015 from India.
This is polyphagous in nature.
It is the most damaging species of thrips on papaya (in Hawaii and Indonesia), pepper and other solanaceous crops (in Indonesia) and ornamentals (in Europe and Indonesia).
As per the literature available, the species is not a vector for virus transmission.
Nature and symptoms of Damage: (Sireesha et al., 2021)
Adjacent Portions to veins are preferred areas for colonizing and feeding.
Deep punctures and scratches on the underside of the leaves.
Yellowish and blotchy appearance in upper surface respective to feeding sites.
Reddish brown discolouration on under the surface of the leaves.
Distorted leaf lamina with necrotic areas and yellow streaks.
In severe infestation new flesh is dried/ blighted.
On floral parts
Scraping on petals results in brownish streaks.
Feeds on pollen which may affect pollination.
Drying and withering of the flower.
Affected fruit set.
With rapid spreading ability, this invasive thrips species affected chilli crop in approximately 9 lakh acres in Telangana and Andhra Pradesh. As per the survey conducted by Dr. Y.S.R. Horticultural University, Andhra Pradesh, yield loss in Guntur district (total area surveyed: 106656 ha) alone is estimated up to 85 to 100% in severely affected areas (60% of the total cropped area), 75 to 85% in moderately affected (18% of the total cropped area), below 50% in less affected (10% of the total cropped area) and 12% of total cropped area is uprooted because of the severe incidence.
Different agencies responded by conducting surveys and creating awareness among the farmers on the identification and integrated management of this pest. Directorate of Plant Protection, Quarantine & Storage (DPPQS) also provided advisory on the incidence of leaf thrips (Scirtothrips dorasalis) and invasive thrips (Thrips parvispinus) to major Chilli growing areas on 10.12.2021 including management strategies for control this pest.
Please check the link for management and detailed information on Thrips parvispinous.
Dr. K. Sireesha, is a Senior Scientist of Entomology, Horticultural research station, Lam, Dr.Y.S.R. Horticultural University, Andhra Pradesh, India
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