Southeast Asia thrips (Thrips parvispinus) are tiny, slender insects measuring 1–2 millimetres, causing significant damage to a wide range of crops. Adult thrips commonly infest flowers and the undersides of leaves, while nymphs remain exclusively on leaf undersides, both of which feed by scraping plant tissues and sucking sap, leading to slowed growth, premature flower drop, and poor fruit formation. Other than chilli, these thrips also affect capsicum, brinjal, and several ornamental plants, making them an increasingly troublesome pest for growers. This article outlines a comprehensive Integrated Pest Management (IPM) approach to reduce crop losses and slow further spread. 

Challenges Posed by T. parvispinus 

Outbreaks of T. parvispinus have intensified across India, especially among smallholder farmers. The pest was first noticed on papaya in 2015, and by 2021, severe infestations were reported in chilli fields of Andhra Pradesh. Regions where chilli is a key crop such as Andhra Pradesh, Karnataka, and Tamil Nadu, have experienced some of the worst impacts. Farmers often report symptoms such as stunted plants, streaked or distorted leaves, and damaged flowers, all of which reduce both yield and market quality. 

Climate change has further accelerated the spread of this pest as warmer temperatures and higher humidity allow thrips populations to multiply rapidly.  

Management Practices 

Management of T. parvispinus has become more difficult due to suspected resistance to commonly used insecticides. Additionally, biological control strategies effective against other thrips species, such as western flower thrips, appear less successful with T. parvispinus. These issues highlight the need for a strategic and collaborative management approach as overuse of chemicals may provide only temporary relief and can worsen resistance problems.  

Let’s explore some effective management practices to curb T. parvispinus. 

Cultural Measures 

• Apply 500 kg of neem cake and 1.5–2 t/ha of vermicompost to strengthen plant health and resilience. 
• Treat seeds with Imidacloprid 70WS @ 10 g/kg or dip seedlings in Imidacloprid 17.8% SL at 0.5 ml/L for 30 minutes. 
• Maintain recommended spacing (60 × 30 cm or 45 × 45 cm); dense planting encourages pest buildup. 
• Plant thick border rows of tall crops like sorghum, maize, bajra, or fodder grasses to reduce thrips movement. 
• Use resistant or early/short-duration varieties to escape peak infestation periods. 

Biological Measures 

• Conserve natural predators by limiting unnecessary chemical sprays. 
• Use microbial insecticides such as Beauveria bassiana or Lecanicillium lecanii @ 4 g/L or 4 ml/L (spore load 1×10⁸ cfu/g or ml), Pseudomonas fluorescens NBAIR-PFDWD at 20 g/L, or Bacillus albus NBAIR-BATP at 20 g/L, covering the entire plant. 
• Apply entomopathogenic nematodes (EPNs), such as Steinernema carpocapsae, as a foliar spray at 10 g/L with 1 g wetting agent. 
• Apply soil drenching of EPNs (S. carpocapsae or Heterorhabditis indica) at 7.5–12.5 kg/ha using 500–750 L of water. Apply early morning or evening to prevent UV damage. 

Botanical Measures 

• Spray 5% Neem Seed Kernel Extract (NSKE), 5% Neem Seed Powder Extract, 0.5% neem oil (5 ml/L), 0.5% pongamia oil (5 ml/L), or 5% Vitex negundo extract (50 ml/L). 
• Apply neem-based formulations containing Azadirachtin 3000 ppm at 2 ml/L. 
• Use 2% fish oil rosin soap (20 ml/L), alone or combined with NSKE. 
• Spray seaweed extract (Kappaphycus alvarezii) at 2 ml/L to boost plant tolerance. 

Chemical Measures 

• Ensure thorough and uniform spray coverage across the entire plant.
• Add recommended stickers or spreaders to improve the effectiveness of insecticide solutions. 
• Avoid unregistered or unapproved agrochemicals such as illegal pesticides, growth regulators, or nutrient mixtures. 
• Rotate insecticides with different modes of action and avoid applying sub-lethal doses to prevent resurgence and resistance. 

Conclusion 

T. parvispinushave become a serious threat to chilli, papaya, potato, and other horticultural crops due to their rapid spread, wide host range, and growing resistance to chemical pesticides. Effective management relies on a well-coordinated IPM strategy that blends different tools together. By following scientific, sustainable practices and encouraging collaboration among farmers and researchers, the agricultural community can limit the impact of T. parvispinus and protect crop productivity in the long term. 

References 

Thrips parvispinus resources (last updated 4/9/2025) – ONfloriculture
Managing Thrips Parvispinus: New Research on Cultural and Biological Control | American Floral Endowment
Thrips parvispinus – MREC – UF/IFAS – University of Florida, Institute of Food and Agricultural Sciences – UF/IFAS
Thrips-parvispinus-(Karny)-Pest-of-concern-to-Indian-farmers-in-Chilli-–-A-Review-Manisha-Yadav-29.pdf
South East Asian Thrips (Thrips parvispinus)-Monitoring and Management_0.pdf 

Photo Credit: L.S. Osborne, University of Florida/IFAS-MREC