Presentation on, Insect Pests of Tea Ravi. Pujari UHS11PGM142 1KITTUR RANI CHANNAMMA COLLEGE OF HORTICULTURE, ARABHAVI 591 310
Pests in relation to different parts of the plant Bud – Mites Aphids Tortrix Matured foliage – Tortrix Mites Matured branches – Shot hole borer Red stem borer Trunk and collar region – Termites Grubs
Tea Mosquito Bug: Helopeltis theivora ( Miridae: Homoptera)Damaging stage – Nymphs and AdultsNature of damage – They suck sap from leaves, buds and tender stems.
Life cycleAdult lay eggs on midrib of leavesFecundity- 100Incubation period- 10-13 daysNymphal period- 22-23 daysAdult – Black head, pale yellow and black thorax,yellow and greenish black abdomen.Nymph is dirty yellow
Symptoms• Leaves show many dry parts due to feeding and also injection of toxic saliva• Die back symptoms
Management• Collection and destruction of parts with pest• Spraying with Dimetoate 1.7 ml / ltr• Helopeltis are predated by Oxyopes sheweta (Lynx spider).
Tea green leaf hopper: Emposca flavescens ( Cicadellidae: Homoptera)• Damaging stage- Nymphs and Adults• Nature of damage – They suck sap from leaves
Life cycleEggs are laid by inserting in the tissue of new tea buds and shoot, particularly in the internode. In one bud upto 7 eggs are laid. Fecundity 100 eggs during her lifetime. Depending on the temperature, the eggs will hatch after 5 - 10 days, producing nymphs. There are five nymph stages. The total nymphal development period is 7 - 16 days being faster in warm weather condition. So, it takes from 12 - 30 days for leafhoppers to complete a generation. There can be as many as 10 generations in a year. The life span of the adults is 14 - 21 days; females in general live longer than males.
• Nymphs are more damaging than adults. Due to intensive sucking the affected leaves curl downwards; the margins become curved, then turn brown and gradually dry up. This typical symptom is called “Rim Blight”.• The midrib and veins of affected leaves also show some what brownish discoloration. Photosynthetic activities is drastically reduced due to loss of chlorophyll, this coupled with imbalance in growth hormones results in stunted plant growth.• Hoppers feeding marks appear small yellow spots. Under dry conditions, the upper part of leaves dry out. The less seriously affected leaves may develop a purple colour.
Management• Natural Management: Ladybeetles, Neuropterans, praying mantids feed on leafhoppers• Tea growing under shade trees tends to have less leafhoppers problem. Mulching also helps to increase humidity and therefore reduce leafhopper populations.• Spraying with Verticillium lecanii @ 2 gm/ltr• Use of light taps• NSKE 5%• Sprays with Monocrotophos @ 1.25 ml/ltr or Imidacloprid 0.25ml/ltr
Tea tortrix : Homona coffearia (Tortricide : Lepidoptera) Eggs are flat and deposited in overlapping clusters Larvae is dark green with a shiny black head The newly hatched larvae tend to move upwards to the growing points of the bush and begin feeding From the second to the fifth instar they make nests by webbing two or more leaves together Mature larva pupates inside the final nest
The adult moth emerges about 10 days later Adult is a grayish brown moth with brown markings on wings Wing span is 16 to 20 mm Larvae
Damage leaves are folded longitudinally. They also attack fruits, shoots, and flowers
Management The introduction of the braconid Macrocentrus homonae Nixon from Indonesia was extremely successful and reduced Homona coffearia to the status of a minor seasonal pest This situation continued until the mid-1950s. Since then, this leaf roller has become serious pest because of the use of chemicals for controlling the shot-hole borer Sprays with NSKE 5% Sprays with Carbaryl 4 gm/ ltr
Bunch catrerpillar: Andraca bipunctata ( Bombycidae: Lepidoptera)• Damaging stage- Larva• Nature of damage- It first feeds on leaf surface by scraping later feeds on leaf margins and they remain clustered in bunches on branches
Life cycle• Fecundity- 150-500• Incubation- 10-11 days• Larval period- 3-4 days• Pupal period- 16-20 days ( soil)• Adult is brownish with dark wavy lines on wings
The Red spider mite: Oligonychus coffeae (Tetranychidae : Acarina) Spherical bright red eggs are deposited by the female on leaves at the rate 4 – 6 eggs a day Three developing stages are found to occur six legged larvae Elliptically shaped female body is broadly rounded at the posterior end and carry the large purple markings
Damage Infest the upper surface of mature leaves Infestation starts along midrib and veins and spreads to the entire upper surface of leaves Affected leaves - bronzed, dry and crumpled
The scarlet mite : Brevipalpus californicus (Tenuipalpidae : Acarina) This species is found on tea and associated trees in tea plantations Eggs are scarlet, Bright red, elliptical and laid under side of the leaves Adults are scarlet, red in color and ovate in shape
Damage This species is found on tea and associated trees in tea plantations Feed on the under surface of leaves, near the mid rib and the petiole of maintenance foliage Heavy infestation leads to defoliation of bushes
Purple mite : Calacarus carinatus (Eriophyidae : Acarina) They are minute worm like mites, having a vast range of host plants including tea Adult female is deep purple colored Body is elongated and spindle shaped, with a broad anterior end
Damage It prefers older leaves to feed on, but during dry spells under heavy infestations, even younger leaves are infested Found on both surfaces of the foliage Affected leaves look dull and matty with a purplish brown discoloration
Yellow mite : Hemitarsonemus latus (Tarsonemidae : Acarina) Eggs are relatively larger – 0.1 mm long Female lays 4 or more eggs a day Life cycle is shorter with no active nymphal stages
Damage Common on tea recovering from pruning and on young tea during post – monsoon periods Losses are felt quickly, because the pest attacks the harvestable part of the plant
Management of Mites• Collection and destruction of infested parts• Spraying of acaricide Dicofol 0.5 ml/ltr
Shot-Hole Borer :Xyleborus fornicates (Scolytidae: Coleoptera) Damaging stage- Adult Nature of damage- It makes holes on the roots and on the lower part of main trunk Grubs, upon hatching feed on a fungus Monocrosporoum embrocium
Life cycle• Fecundity-• Incubation- 10-12 days• Larval period- 45-60days• Pupal period- 20-30 days (tunnel)• The adults are small in size brown, reddish brown or black in colour, head completely bending downwards with blunt end• Activity- Winter months
Symptoms Yellowing of lateral branches Small pin holes on main trunk Oozing of fiberous material from the trunk Crop losses due to the SHB have been assessed to be in the rang of 18 – 40 %
Management• Avoid water logging• Swab Carbaryl paste around stem upto 2 feet from base• Drenching with Chloropyriphos 2.5 ml/ ltr
• Red stem borer : Zeuzera coffeae (Cossidae: Lepidoptera)• Adult - orange colour, medium sized mothThe adult has white and black spotted wingsThe larva is red coloured
Life cycle : Eggs are usually laid singly on the bark Eggs hatch in 8 – 12 days and larval development takes 3 – 4 months Pupation takes place inside the stem and the adult emerges in about 2 months Adult is a nocturnal moth
• Damaging Stage : Larva• Nature of damage & Symptoms of damage:• Caterpillar bores into the stem or branches to feeds on the wood.• In early stages of attack, young plants or braches show wilting.• Pellet-like excrement of the larva hangs out and accumulates at the base of the plant.• In advanced cases, the branch dries up.
Management• Affected plants or twigs should be cut and burnt.• Providing good shade to plantation.• Field release of white muscardine fungus B. bassiana and braconid parasite Amyosoma zeuzerae.• Spraying NSKE at 4 percent.