By Timmanna
The invasive South-East Asian thrips, Thrips parvispinus (Karny) also known as ‘black thrips was first reported from India during 2015. It is believed to be originated from Thailand and took five years to get adapt and establish under Indian conditions. For the first time, the widespread infestation was noticed during the post-rainy season 2021 in South Indian states viz., Karnataka, Telangana and Andhra Pradesh. The chilli growing areas in North Eastern Karnataka districts viz., Raichur, Bijapur, Bellari, Yadgir, Koppal, Bidar and Kalaburagi were severely affected by this new invasive thrips pest. Locally, the symptoms of thrips infestation are called Tamara Roga or Bronze disease, Chilli farmers in these areas are living their worst nightmare. As per the recent survey reports of state agriculture departments, DPPQ&S and ICAR, this pest infested nearly 60 to 80% of chilli growing area and significant economic loss covering more than 10 lakh acres of chilli crop in south Indian states was witnessed in a matter of months. Farmers complained about the pesticides being ineffective in managing this pest.
The entomologists in this region are helping farmers to fight this battle. Dr. Arunkumar Hosamani, Professor of Entomology, University of Agricultural Sciences, Raichur and his team leading the fight in this region with farmers.
Small biocontrol unit fulfilling high demand: AICRP on Bio-control at UAS, Raichur, a branch of AICRP on Bio-control of ICAR-NBAIR, Bengaluru was started during 2016. Since then, started mass production of macrobes and microbes. Among microbes, Metarhizium anisopliae, Beauveria bassiana, Lecanicillium lecanii and Nomuraea rileyi were mass produced in a large scale and distributed to the farmers. Along with bioagents they are also mass producing four species of Trichogramma procured from ICAR-NBAIR, Bengaluru for the management of lepidopteran pests in rice, maize, groundnut and sugarcane ecosystem.
Dr. Arunkumar Hosamani shares with Dr. Timmanna about farmers practice and his experience for managing invasive thrips
Farmers in six districts of Kalyana Karnataka growing chilli cultivars like HPH-2043, HPH-5531, Red patti, Byadagi chilli, Guntur super 10, Namdhari chilli and Teja. Among these Red patti is very susceptible. In case of HPH-2043 and HPH-5531 variety, infestation is found to be less compared to other varieties. The common synthetic insecticides like Pegasus®, Benevia® and Delegate® were being used for the management of this pest. Some farmers are using combination of neem oil, sesamum oil and mustard oil along with the chicken eggs for spraying.
Initially, when we noticed this pest in Raichur district, we have recommended Adhoc insecticides (CIB&RC) against this pest. Unfortunately, we didn’t’ observe satisfactory results and also received different opinions from the farmers. During 2021, we have switched to entomopathogenic fungi like Beauveria bassiana, Isaria fumosorosea, Metarhizium anisopliae and Lecanicillium lecanii and also evaluated its usage against this pest in farms and distributed few packets of bio agents for demonstration to farmers. Surprisingly significant reduction (50-60%) of thrips population was observed after two to three sprays.
Later this news was spread from one farmer to another and one village to another. Within a span of one month, we started receiving nearly hundreds of phone calls from farmers every day. To meet this huge demand, on first-come-first basis we initially distributed four pockets of microbials per farmer, then increased the mass production of Beauveria bassiana (ICAR-NBAIR Bb5a) and Isaria fumosorosea (ICAR-NBAIR-Pfu5) in the laboratory.
During the crop season, weekly on an average 1.5 tonnes of M. anisopliae and L. lecanii and nearly 10-12 tonnes of B. bassiana and I. fumosorosea per month were mass produced and distributed to the farmers of Karnataka, Telangana and some parts of Andhra Pradesh.
Also recommended spraying methodology: Mixture of B. bassiana (1kg) + I. fumosorosea (1kg) per acre (5g/liter water) used by physical mixing at the time of spraying, which could able to record 80 % reduction of thrips populations after five days.
Further, combination of Beauveria bassiana + L. lecanii or Beauveria bassiana + I. fumosorosea were packed in a single kit (4 kg), it consists of 2 kg M. anisopliae or 2 kg B. bassiana+ 2 kg L. lecanii or 2 kg I. fumosorosea, this kit is sufficient for 2 acres area for management of chilli black thrips.
During this process, a regular farmer’s visitor’s book was maintained; transportation facility was provided for those who were unable to visit the laboratory. The mass production plan was framed properly, executed healthily, monitored the farmers feedback carefully both in the field and laboratory.
Since this pest is new to the Indian condition and also it is free from natural enemies, synthetic insecticides are costly and its wrong or indiscriminate use may invite the control failure. The Biocontrol Unit UAS, Raichur advise the farmers of the region to be cautious and popularised use of B. bassiana and I. fumosorosea which is giving satisfactory results when sprayed weekly. However, the fight is still on against invasive thrips in this region, but their effort to address the invasive pest problem along with farmer’s participation is commendable.
Dr. Timmanna is a Scientist at the ICAR-CRIDA, Hyderabad and also the Associate Editor of Indian Entomologist.
Email: thimsento@gmail.com