Thrips-Free Harvest: Proven Methods for Managing Black Thrips in Chilli Crops

  • , by Agriplex India
  • 12 min reading time

India holds the distinction of being the largest producer of chilli globally, contributing to approximately 36% of the world's production. Farmers in India have effectively managed pest and disease infestations by adopting Integrated Pest Management techniques. However, recent challenges have emerged for farmers in Andhra Pradesh, Telangana, and Karnataka, as they have experienced significant crop losses due to the invasion of a new thrips species called Thrips parvispinus (Black Thrips). Immediate action is required to develop management strategies to combat this invasive pest. 

Identification and Life Cycle of Black Thrips:

Black thrips are small, measuring about 1-2 millimeters in length, making them difficult to detect without close inspection. They have dark or black bodies with slender, elongated shapes and fringed wings. These pests undergo incomplete metamorphosis, with egg, nymph, and adult stages comprising their life cycle. Female thrips lay their eggs on host plants, which hatch into nymphs that go through two active stages before reaching adulthood.

Life Cycle of Black Thrips In Chilli

Crops Vulnerable to Black Thrips Attack:

Black thrips are highly adaptable and infest numerous crops, including:

     a) Fruits: Citrus fruits, mangoes, grapes, strawberries, and peaches.

     b) Vegetables: Tomatoes, peppers, eggplants, cucumbers, beans, and okra.

     c) Field Crops: Cotton, maize, soybeans, and sunflowers.

     d) Ornamental Plants: Roses, chrysanthemums, orchids, and various flowering plants.

    e) Other Crops: Tea, coffee, spices, and medicinal herbs.

Impact of Black Thrips Attack on Chilli Crop:

  1. Feeding Damage: Thrips feed on plant tissues, leaving characteristic silvery or bronze scars on leaves, flowers, and fruits. This feeding damage leads to stunted growth, distortion, and deformation of plant parts.
  2. Transmission of Diseases: Thrips act as vectors for several plant diseases, including Tospo viruses, which can cause severe damage and even plant death.
  3. Reduced Photosynthesis: Continuous feeding by thrips can disrupt the photosynthetic process, affecting the plant's ability to produce energy and limiting its growth potential.
  4. Fruit Damage: Black thrips infestation often results in scars, deformities, and premature fruit drop, rendering the harvested fruits unmarketable or unsuitable for further processing.
  5. Crop Quality and Marketability: Thrips damage can diminish the overall quality and market value of crops, impacting the income and livelihoods of farmers.

Favorable Conditions for the Spread of Black Thrips 

The spread of black thrips (Scirtothrips dorsalis) is influenced by favorable conditions, including warm temperatures (25°C-30°C), high humidity, the availability of susceptible host plants, a lack of natural predators, favorable climatic conditions, agricultural practices, and international trade. These factors contribute to the rapid spread of black thrips.

Symptoms of Damage in Crop by Black Thrips

  • Silvering or bronzing of leaves: Black thrips feeding on chili leaves can result in a silvering or bronzing appearance, caused by tiny punctures and sap extraction.
  • Deformed and distorted leaves: Continuous thrips feeding can lead to the deformation and distortion of chili leaves, causing them to curl, twist, or become misshapen.
  • Scarring on fruits: Black thrips can leave scars on chili fruits, creating small, discolored, and sunken areas on the surface, which can make the fruits less appealing and lower their market value.
  • Premature fruit drop: Severe black thrips infestations can weaken the fruit stems, causing premature dropping of chili fruits from the plant.
  • Stunted growth: Thrips feeding on plant sap can impact the overall growth and development of chili plants, resulting in stunted growth and reduced productivity.
  • Spread of viral diseases: Black thrips are known vectors for viral diseases, which can be transmitted to chili plants during feeding, leading to more severe symptoms and decreased crop yield.

Preventive Measures

  • Regular Monitoring: Regularly inspect chili plants for early signs of thrips infestation, such as silvering leaves, distorted foliage, or scarring on fruits. Early detection allows for timely intervention.
  • Crop Rotation: Practice crop rotation by planting chili in different locations each season. This helps disrupt the life cycle of thrips and reduces the likelihood of recurring infestations.
  • Clean Cultivation Practices: Maintain a clean growing environment by removing weed hosts and plant debris that can harbor thrips populations. Thoroughly clean equipment and tools to prevent the transfer of thrips between plants.
  • Beneficial Insects: Encourage the presence of beneficial insects, such as ladybugs, lacewings, or predatory mites, which feed on thrips. These natural predators can help control thrips populations.
  • Physical Barriers: Install physical barriers like insect nets or row covers to prevent thrips from accessing chili plants. These barriers create a protective barrier and reduce thrips infestation.
  • Reflective Mulch: Use reflective mulch around chili plants. The reflective surface disorients thrips and deters their movement towards the plants.
  • Proper Irrigation: Maintain appropriate irrigation practices to avoid overwatering, as excessive moisture can create favorable conditions for thrips. Water the plants at the base to minimize leaf wetness.
  • Sanitation: Remove and destroy infested plant materials, including affected leaves and fruits, to reduce thrips population and prevent their spread to healthy plants.
Biological Control Method of  Black Thrips 

     Implement biological control methods by introducing beneficial insects or using biological pesticides specifically targeting thrips. These methods provide environmentally friendly options for thrips management.

    • Placing yellow or blue sticky traps to monitor and catch adult thrips, providing an early warning of thrip activity and reducing egg laying.
    • Spraying of Liquid Solution Combination of Beauveria bassiana, Verticillium lecanii, and Neem Oil, each containing 3 ml /Litre of water at intervals of 7 days will help in effectively controlling the spread of black Thrips
    • Introducing predatory bugs such as Orius-System in the field can also help in controlling the spread of thrips
    Chemical Control of Black Thrips:

       If necessary, use insecticides labeled for thrips control as a last resort. Follow the instructions and safety precautions provided by the manufacturer and consider the potential impact on beneficial insects.

      Below are the Top chemical Insecticide to control Black  Thrips in Your Crop

      • Gracia Insecticide belongs to the isoxazoline class with broad-spectrum activity. Its unique mode of action works effectively against both sucking and chewing pests
      • Keefun Insecticide - Keefun belongs to the pyrazole group, novel chemistry. Globally, Keefun has been developed to control a wide range of insect pests viz hoppers, aphids, Diamond Back, and Thrips
      • Exponus Insecticide - Powered by the active ingredient Broflanilide and is Effective on targets that have developed resistance against multiple MOAs
      • Raise Insecticide Raise insecticide is an anthranilic diamide Broad Spectrum insecticide in the form of a suspension concentrate. It offers a unique mode of action that controls pests resistant to other insecticides.
      • Solomon InsecticideIt contains Imidacloprid and Beta- Cyfluthrin. Beta-cyfluthrin is an insecticide of the synthetic pyrethroid group. Beta-cyfluthrin is acting by contact and ingestion. It acts on the insects’ nervous system as a sodium channel blocker.
      • Jump Insecticideis a Fipronil-based phenyl pyrazole insecticide. Jump is very effective in controlling stem borer and leaf folders in rice. Fipronil not only controls insect pests effectively but also shows plant growth enhancement effects which result in higher yields.

      Annexure: CIB & RC approved registered Insecticides for Thrips in Chilli

      Insecticides

      Dosage per ha in required water waiting period (in
      days)

      Acephate 95 % SG

      790 gin 500 L

      7

      Acetamiprid 20 % SP

      50-100 gin 500-600 L

      3

      Carbofuran 03 % CG

      33.30 kg

       

      Cyantraniliprole 10.26% OD

      600 in 500 L

      3

      Dimethoate 30 % EC

      600 ml in 500-1000 L

       

      Emamectin benzoate 05% SG

      200 g in 500 L

      3

      Emamectinbenzoatel .90%EC

      375 ml in 500 L

      14

      Ethion 50 % EC

      1.50-2.00 L in 500-1000 L

      5

      Fenpropathrin 30 % EC

      250-340 ml in 750-1000 L

      7

      Fipronil 05 % SC

      800-1000 g in 500 L

      7

      Fipronil 80 % WG

      50.00-62.50 g in 500 L

      5

      Imidacloprid 70 % WS

      1.00-1.50 kg

       

      Imidacloprid 30.50%m/m SC

      125-150 g in 500 L

      5

      Imidacloprid 17.80 % SL

      125-250 ml in 500-700 L

      40

      Lambdacyhalothrin 4.90%CS

      500ml in 500 L

      5

      Lambda-cyhalothrin 05% EC

      300 ml in 400-600 L

      5

      Methomyl 40 % SP

      0.75-1.12 kg in 500-1000 L

      5

      Oxydemeton-methy125% EC

      1 Lin 500-1000 L

      -

      Spinosad 45 % SC

      160 ml in 500 L

      3

      Spirotetramatl 5.31 %w/wOD

      400 gin 500 L

      5

      Thiamethoxam 30 % FS U

      Used as Seed Dresser

       

      Diafenthiuron 47 % + Bifenthrin 09.40
      % w/w SC

      625 ml in 500 L

      7

      Flubendiamide 19.92 % + Thiacloprid 19.92 % w/w SC

      200-250 ml in 500 L 

      5

      Profenofos 40 % + Fenpyroximate 2.5
      % w/w EC

      1 Liter in 500 L

      7


      Ref - https://www.iihr.res.in/sites/default/files/South%20East%20Asian%20Thrips%20%28Thrips%20parvispinus%29-Monitoring%20and%20Management_0.pdf

      Insecticides to Avoid

      Avoid foliar sprays of other organophosphate insecticides (e.g., malathion), carbamates (carbaryl*), or pyrethroids (e.g., bifenthrin, cyfluthrin, fluvalinate, and permethrin). These materials are highly toxic to natural enemies and pollinators can cause spider mite outbreaks, and are not particularly effective against most thrips. 

      Conclusion 

      By implementing these preventive measures, farmers and gardeners can effectively manage and reduce the risk of black thrips infestation in chili plants, ensuring healthier crops and higher yields. IPM (Integrated Pest Management) can also.

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      • Black thrips white thrips in cryasanthamum

        MA

        Marilingaiah

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