Tobacco Thrips in Tobacco
The adult of Tobaccotripsy (Thrips tabaci Lind.) is 0.8-0.9 mm in length. The color is light yellow in summer forms and slightly darker in winter forms. The head is broad and rectangular. Antenna 7 segmented, short and bristly. The thorax is wide. Their bodies are cylindrical and the abdomen ends by thinning. The wings are two pairs and narrow. Wing edges are fringed in the form of eyelashes. Abdomen consists of 10 segments. It has yellowish brown spots on it. Males are smaller.
The larvae are white when they first hatch from the egg. As it develops, the color changes to light yellow and wing marks are visible. Wings and antennae are quite prominent in mature nymphs. The first instar nymph is white, the second instar nymph is light yellow in color and 0.9 mm in length. Eggs are oval in shape, 0.3 mm in length and white in color.
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It spends the winter mostly in the adult and sometimes in the larval stage in the soil or under the debris. They can also overwinter in the bulbs left in the field. They emerge in the spring and feed for a short time. They lay their eggs in the leaf tissue close to the veins in scattered or short rows. Usually a female lays 30 eggs. This number may vary depending on the host plant and climatic conditions.
Larvae hatching from eggs in about a week spend 4 periods. They are fed in the first three periods, they are lethargic and do not feed in the fourth period. Then they enter the soil and become pupae. After a certain period of time, new adults appear. The development period from egg to adult lasts 2-3 weeks. They continue to reproduce with unfertilized eggs. Males are rare in nature. It can give an average of 3 offspring per year, and more under favorable conditions.
In places or years with dry summer months, their development and reproduction accelerate. Continuous rains wash the pest on the plant, reducing the population considerably.
It is found on the leaves, buds and flowers of the plant, adults and larvae feed on plant sap. The suction points take a transparent appearance due to the sap discharged in the tissues. In dry seasons, water loss is faster in damaged tissues.
In the tobacco plant, the leaf is sucked, especially near the veins, and many white spots occur along the veins. This form of damage is colloquially called "vein disease". Depending on the insect density and, accordingly, the degree of absorption, the leaf may lose its commercial value. Another form of damage occurs as a result of breaking the leaf tissue with egg laying tubes and laying eggs in the tissue. Although it is not found in tobacco production areas to attract attention every year, economic losses have been determined from time to time and locally. It is generally harmful in the young period of the plant.
It is common in the tobacco planting areas of the Aegean, Marmara and Black Sea Regions. It becomes harmful at the beginning of the season in the dry years in the Southeastern Anatolia Region.
Tobaccotripsy is polyphagous. Tobacco, onion, cotton, vine, tomato, potato, bean and various ornamental plants and some weeds are among its hosts.
There is no natural enemy detected in the tobacco plant.
Cultural Measures
- Residues in the nursery and field should be collected and destroyed.
- Seedlings should not be established and planting should not be done in places or fields known to be contaminated before.
-Contaminated seedlings should not be transferred to the field.
-The bottom leaves should be collected early.
- Weed cleaning should be done.
-Hoeing affects the pest in the pupa period negatively.
Spraying is done when there is an average of 5 tobaccotrips per leaf.
Back sprayer (mechanical, automatic, motorized) or back atomizer is used in spraying.
Spraying should be done in the morning or in the evening, in a windless weather, in a way to cover the lower surfaces of the leaves. Plant protection products used in the field cycle are applied at most twice between planting and breaking of the fourth hands.
* Ministry of Agriculture, Agricultural Protection Technical Instructions Vol:2