Pest Control in the Garden!!!

By Arun Pratap Singh
Plant diseases are normally caused by living organisms called parasites. Plants can suffer from bacterial, viral and fungal attack just as we can. Important pests that suck the sap from the plants are mealy bugs, scale insects, aphids, thrips, jassids and mites of several kinds. The affected leaves curl up and get deformed. Chewing insects like Beetles, Cutworms, Grubs, Weevils, Locusts and several kinds of Caterpillars feed on leaves and other parts of the plants. Several kinds of flies and maggots lay the eggs under the fruit skin and feed on the pulp. Borers make holes in the stem, shoot, fruit or even the roots of the plants. Slugs and snails cause serious damage. Termites can be another serious problem in any garden. Chemical control is usually necessary where manual removal of pests is not possible.
Aphids: These are small insects and attack Rose, Dahlia, Chrysanthemum, annuals and some vegetable and fruit crops. The active period is usually March to May in Uttarakhand.
Control: Dichlorovos (Nuvan), Methyl Parathion (Metacid) or Dimethoate (Rogor) can be effectively used @ 2 ml/litre of water as foliar spray.
Jassids: They are tiny sucking insects that attack Rose, Dahlia, Chrysanthemum, Carnation, Gerbera, several ornamental plants, some annual flowering plants and some vegetable crops like Okra (Bhindi). Both the nymph and adult feed on leaf sap resulting in yellowing or bronzing and curling of leaves.
Control: Dichlorovos (Nuvan) 35 EC. For vegetable and fruit crops, it is better to spray Fenvalerate (Tatafen of M/s Rallis India) @ 2 ml/litre of water.
Thrips: These small insects suck the sap of the leaves. They attack roses, carnations, chrysanthemum, bulbous plants and annuals. The infested surface of the leaf or fruit becomes corky. They are most active during August to November. The result is creamy or yellow spots on the leaves. Control: Dimethoate (Rogor of M/s Rallis India) 30 EC, Ethion (Sumithion) 50 EC, Monocrotophos (Nuvacron or Monocil) 40 EC @ 2 ml/litre of water to be sprayed at 7 to 10 days interval.
Beetles: The beetles are round with the head hidden by the wings. They are brownish-yellow to deep orange with black spots or patches. Beetles attack marigold, aster, petunia, lilies and several others among the flowers and Cucurbits (gourds, cucumber and melons) and brinjal among the vegetables.
Control: Dichlorovos (Nuvan) 76 EC, Quinalphos, Endosulphan 35 EC @ 2ml /litre of water to be sprayed.
Grubs: Grubs are the larval stage of the Beetles. Grub damage in lawns occurs in spring and early summer when larvae feed on the roots of grass causing the grass plant to turn brown and die. Chafer grub attacks roses and several other plants. The larvae also damage the roots of strawberries, potatoes and other garden vegetables. They cause defoliation in flower beds, shrubs and trees.
Control: Application of Chlorpyriphos 20EC @ 2ml/ litre of water or Phorate 10G (Granules) in the soil or dusting the soil surface and the plant foliage with Lindane 6.5 % WP should do the job. Fenvalerate 10EC @ 3ml/litre can be used as a contact poison.
Caterpillars: There are several types of caterpillars and they cause severe damage to ornamentals and vegetables like cauliflower, cabbage, lettuce, peas, potatoes and onions, amongst others. They can be hairy or non-hairy and of various colours. They are fruit eating, bud eating, bark eating or leaf eating.
Control: Cypermethrin 25 EC or Fenvalerate 10 EC @ 1.5 ml/litre of water should be sprayed at weekly intervals to achieve effective control. Traditionally, Endosulphan has been used @ 3ml/litre though it is best avoided in a home garden.
Cutworm: Cutworms usually stay in the soil during the day and come out during the night to feed on different parts of the plants. They usually attack chrysanthemum, carnation, marigold, bulbous plants like gladiolus. Vegetable crops like cabbage, cauliflower, beans, peas, lettuce and leafy vegetables are also attacked by cutworms. The cutworm chews into the plant’s stem at the ground level and chops it off. Once the attack occurs, immediate attention is required, because they attack and destroy rather rapidly.
Control: Against this pest only stronger pesticides are effective. Chlorpyriphos 20 EC or Endosulphan 35 EC and Carbaryl can be used as soil drench for very effective control.
Mites: A powerful hand lens is needed to see these pests. They are eight-legged insects found mostly on the underside of the leaves of vegetables, fruit trees, roses and other flowers, especially during the hot dry summer. One can see webbing similar to spider webs around the colonies of spider mites on leaves, stems, fruit and houseplants.
Control: In home gardens, Dimethoate (Rogor of M/s Rallis India) is the most common pesticide for this pest. The rate of application is 2 to 3 ml/litre of water. Endosulphan 35 EC, Quinalphos 25 EC. New formulations with better efficacy and safety profile like Fenpropathrin (Danitol of M/s Rallis India) 10 EC @ 1.5 ml/litre of water as spray. Red Spider Mite: They are similar in nature and action to other spider mites. They are bright red during the cooler months of the year but in summer they may turn yellowish or greenish. They usually attack rose, tea plantations but can infest almost any house plant in Uttarakhand. While in the northern plains they are destroyed to a large extent by scorching heat during May and June, they continue to survive in areas with milder climate like Dehradun, and the hills.
Control: Phorate 10 G granules are applied to the soil to the depth of 2 to 3 inches every three months at the time when new flush of leaves appears. Quinalphos, Ethion 50 EC (Fosmite or Sumithion), Oxydemeton Methyl (Metasysox of M/s Bayer India) and Endosulphan are also effective in controlling this pest. Fenpropathrin (Danitol of M/s Rallis India) 10 EC @1.5 ml/litre of water is used as spray.
Scale insects: These are small tiny insects with tough scales and are of varying colours and shapes depending on the species. These are very severe pests on a number of fruits, vegetables and ornamental plants, including roses. The scale insects have special preference for the rose family. They are tiny, with minute sucking mouth parts with which they suck the cell sap. The tree bark gets covered with a grey layer of overlapping scales. These insects are more active during February-March and August-October in Uttarakhand.
Control: Contact insecticides like Malathion and Systemic insecticides like Monocrotophos (Nuvacron), Ethion (Sumithion or Fosmite), Phosphamidon (Dimecron) and Oxydemeton-methyl (Metasystox of M/s Bayer) are effective against the scale insects.
Whiteflies: These pests can be detected when the plant is touched and the small white insects start to fly out. Tomato and Cabbage families of plants among the vegetable crops and Begonia, Geranium and Fuchsia among the ornamentals are the chief targets.
Control: Monocrotophos 36 SL @ 2 ml/ litre of water, Oxydemeton-methyl (Metasystox) 50 EC @ @ ml/litre, Ethion (Sumithion or Fosmite) 100 EC @ 1 ml/litre of water and Profenofos (Curacron of M/s Syngenta India) 50 EC @ 1ml/litre.
Fruit and Stem Borers: There are several species of Fruit, Stem, Pod and Bud Borers in India.
Control: All the wilted shoots should be pruned. Preventive measures of control are more effective. Fenvalerate 10 EC (Tatafen of M/s Rallis India) @ 1.5 ml/litre of water, Cypermethrin 25 EC or Monocrotophos 70 EC @ 2 ml/ litre of water can be sprayed at fortnightly intervals during the fruiting season. Another new generation chemical Profenofos 50 EC @ 1 ml/1.2 litres of water can be sprayed for better effect at the eggs stage. It has been observed to be effective against the eggs too. The crop should not be harvested for a week after the spray.
Termites: They normally appear in dry soil and attack both woody and herbaceous plants. They attack the roots of lawn grasses also. In India, the main pesticide used for termites is Chlorpyriphos. DDT, Aldrin and BHC have been banned and must not be used.
Control: The soil is normally drenched with Chlorpyriphos 20 EC @ 3 ml/litre of water. Lindane dust can also be mixed in the soil for control. Fenvalerate is also effective and is also used as house termiticide.
Diseases: There are a number of diseases which also attack the plants besides the pests and are usually of fungal, bacterial or viral generated. Viral diseases like Leaf Mosaic or Leaf Curl Virus are usually untreatable and it is better to destroy the affect plant as soon as the disease is observed. Many of the diseases are transmitted by pests that are carriers of these diseases. Preventing pests and fungi is effective way to prevent many diseases. However, a separate detailed article on diseases and their treatment would be done separately.