Biology and Nature of Damage

Damage symptoms

Feeding Damage

• Bugs use needle-like mouthparts to pierce plant tissues and suck sap, causing localized cell death.

On Young Shoots and Leaves

• Wilted tips, black/brown spots, curling, and stunted growth. Severe cases may result in dieback.

On Fruits

• Developing guava fruits show puncture marks that become sunken and blackened, leading to potential drop or unmarketable quality.

Secondary Infections

• Feeding wounds may allow entry for fungal or bacterial pathogens, worsening damage.

Management

• Prune your guava trees to improve sunlight exposure and air circulation.
• Eliminate infested shoots, young fruits, and fallen debris to reduce breeding sites for pests.
• Avoid planting alternate hosts like cotton, tea, cashew, mango, sweet potato, moringa, and neem near guava orchards, especially during the peak incidence period from July to October.
• During this peak period, collect nymphs and adults using a beating tray and dispose of them in soapy water.
• Use Multiplex Baba (Beauveria bassiana) and Varsha (Verticillium lecanii) along with Multiplex Biostrike at a concentration of 3 ml/L every 3 to 4 weeks, starting at the fruit set stage.
• During the flush stage, spray Multiplex Nagphos (Monocrotophos 36 SL) at a rate of 2 ml/L. - Alternatively, you can rotate systemic insecticides such as Navatara (Thiamethoxam 25 WG) at 0.5 g/L or Vigilant (Lambda Cyhalothrin 4.9 CS) @1ml/L . - Also, consider using a combination of Fenazquin 10% + Bifenthrin 4

At least two sprays are recommended from the flushing to the fruiting stage to ensure a quality yield. During the fruiting stage, apply Multiplex Baba (B. bassiana) every 3 to 4 weeks.

By following these practices, you can better manage pests and enhance the quality of your guava yield.

What is the Tea Mosquito Bug?

The tea mosquito bug belongs to the Miridae family under the order Hemiptera. This pest is commonly found across India. It is notorious for attacking cashew, guava, moringa, neem, tea, and cocoa crops. cashew, cocoa crops and even some vegetables and weeds.

The bug's feeding on tender shoots, panicles, nuts, and fruits causes significant damage, leading to yield losses. In tea, for example, it can cause yield losses of 30-50%. The pest injects enzymes into the plant tissue while feeding, causing browning and scab-like lesions.

The adult tea mosquito bug is small and slender, black in colour with a red thorax and greenish-brown wings. Its most distinguishing feature is an erect, T-shaped knob on the scutellum (a small shield-like structure on its back), which gives it the nickname "T mosquito bug." These bugs are mainly active during early morning and late evening hours, and tend to hide in bushes during the hotter parts of the day.

Understanding Its Life Cycle and Feeding Behaviour

A single female can lay between 100 to 200 eggs in her lifetime. The eggs are inserted one by one into the tender parts of the plant, mostly in young shoots, flower buds, and leaf petioles. After about seven days, the eggs hatch into greenish-yellow nymphs. These nymphs are wingless at first but gradually develop wing buds as they pass through five growth stages (instars) over the next 10 days.

Both the nymphs and adults are sapsuckers. Using their needle-like stylets, they puncture tender plant parts and inject toxic saliva. This not only removes vital plant nutrients but also causes a localized death of plant tissue, which appears as reddish-brown or black spots. Over time, these small spots merge into larger necrotic patches, leading to curling, stunting, and drying of shoots and leaves.

Recognizing the Damage

Being able to identify early signs of tea mosquito bug damage is essential for timely intervention. Here's what to look for:

On Shoots and Leaves

• Wilted or curled leaf tips
• Black or brown necrotic spots
• Stunted growth and dieback in severe cases

On Fruits (especially guava)

• Tiny puncture marks on the fruit surface
• Blackened and sunken spots around the puncture site
• Premature fruit drop or unmarketable fruits due to visual damage

Secondary Infections

The feeding wounds created by the bug often serve as entry points for fungal and bacterial pathogens, compounding the damage and accelerating fruit decay.

How to Manage the Tea Mosquito Bug

Managing this pest requires an integrated approach combining cultural, biological, and chemical strategies.

Cultural Control

• Pruning: Regularly prune guava trees to improve air circulation and light penetration. This reduces favorable conditions for the T mosquito bugs.
• Sanitation: Remove infested shoots, damaged fruits, and fallen leaves to cut down breeding grounds.
• Host Avoidance: Do not plant alternate hosts like cashew, cotton, mango, moringa, neem, or sweet potato near guava orchards—especially during peak infestation months (July to October).

Mechanical Control

• During the peak season, collect nymphs and adults using a beating tray and destroy them in soapy water. This simple method helps significantly reduce the adult population.

Biological Control

• Use Multiplex Baba (containing Beauveria bassiana) and Varsha (Verticillium lecanii) at 3 ml/L. Apply every 3 to 4 weeks from the fruit-setting stage to reduce pest buildup.
• These biocontrol agents infect and kill the bugs naturally, reducing chemical reliance and promoting ecological balance.

Chemical Control (to be used judiciously)

• During the flushing stage, spray Multiplex Nagphos (Monocrotophos 36 SL) at 2 ml/L.
• Rotate systemic insecticides such as:
  • Navtara (Thiamethoxam 25 WG) @ 0.5 g/L
  • Vigilant (Lambda Cyhalothrin 4.9 CS) @ 1 ml/L
  • Combination spray: Fenazaquin 10% + Bifenthrin 4%

Apply at least two rounds of insecticide sprays from the flushing to fruiting stage for effective control. Ensure you follow proper safety measures and pre-harvest intervals while using chemicals.

The tea mosquito bug may be tiny, but its impact on guava and cashew production is massive. With rising concerns about pest resistance and chemical overuse, an integrated pest management (IPM) strategy is the way forward. By combining biological inputs like Beauveria bassiana and Verticillium lecanii with good orchard hygiene and timely chemical sprays, farmers can keep this pest in check without harming the environment.

Consistent monitoring, early detection, and scheduled management interventions can drastically reduce damage and improve the quality of your harvest.