Pest:Pollu beetle

Longitarsus nigripennis.

Pollu beetle is the most important and a specific pest of Pepper. The adult is a small shiny blue beetle about 2.5 mm in length. Its hind legs are stout and modified for jumping long distances. On receipt of pre monsoon showers pepper plants start putting forth new flushes. Then the residual population growing in shaded areas becomes active. Beetle spend its life cycle on new flushes feeding on tender leaves and boring in to tender shoots till the plant put froths spikes. Once the spike appears the beetle moves to the spike. Berries are attacked when they start appearing.

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  • pest 1
  • pest 2
  • pest 3
  • pest 4

Symptoms

  • With the appearance of new flushes beetle lays eggs on them. Emerging grubs bores in to tender shoots and as a result the tender shoots dry. Beetle also lays eggs on tender leaves, the emerging grubs scrape and feed on leaves.
  • Portions of leaves subjected to attack by the grub later dries and are blown away by wind and result in the formation of holes on leaves.
  • Beetle also feeds on leaves resulting in feeding holes.When spikes are formed the beetle lays eggs on the spike.
  • The emerging grubs bore in to the spike and the spike beyond the area of damage breaks resulting in "murithiri"(broken spike). When the spike develops and become hard the grub feed on the skin of the spike.
  • Damage to spike affects the berry formation badly. When the berries are formed the beetle makes small holes on the berries and lays egg.
  • Attacked berries become hollow and crumble when pressed. Such hollow berries are called pollu berries .

Procedure for Observation

Observe 20 standards selected randomly from the plot and assess the % of spikes showing the damaging symptoms by selecting 10 spikes at random from each standard and work out the average. Rate the damage as < 2 % Mild; 2- 4% moderate and >4 % severe.

ETL

  • 4 % damage.

    • Control Measures

  • Regulate shade in the plantation.
  • Spiders such as orb weavers and hunting spiders help in reducing the population of pollu beetles.
  • Application of neem cake at the base and incorporation will help in killing the pupae.
  • Spraying the plants with 1 % Bordeaux mixture will act as a repellant.
  • Spray any one of the following insecticides- dimethoate or quinalphos @ 0.05%. Spraying has to be given at the time of spike emergence (June-July); at berry formation (September- October) and again at berry maturing stage when needed.
  • Spray neem oil garlic emulsion 2% at spike emergence, berry formation and berry maturing stages.
  • Spray neem based insecticides @ 4 ml/l of water.
  • Residual population of the beetle can be managed by spraying formulations like Metarrhizium anisopliae ,or Beauveria bassiana @ 20 g/L or 5ml/L.