Plant protection from leaf miners
One of the serious types of damage to the leaf apparatus of plants is the damage caused by the larvae of mining flies and moths, or leaf miners. The females of these pests are armed with a proboscis, with which they pierce plant tissue to suck food or lay eggs.
The pests themselves are yellowish-white or brownish larvae 2-3 mm long. These larvae gnaw typical mined passages in the leaves for several days, and then they pupate inside the leaves or on their surface.
The pupal stage lasts from 8 to 14 days, then an adult insect hatches from it. In total, the development of an adult insect from an egg takes only three weeks.
Female miners, piercing the epidermis of the leaf, are capable of transmitting plant pathogens, for example, such as mosaic viruses of soy, tobacco, celery and watermelon.
Symptoms of plant damage with leaf miners
Depending on the type of miner, passages gnawed by larvae can be found on the lower or upper side of the leaves. Most species specialize in certain plants; others mine a wide variety of plants. They infect ornamental plants, vegetables and shrubs.
The first sign of a lesion is small pits on the leaves - puncture marks left by the females.
Methods of dealing with leaf miners
Methods of dealing with mining flies and moths at different stages of development of these insects are different.
Eggs are destroyed with paraffin-containing agents. Larvae have many natural enemies. This is primarily riders laying their eggs in the larvae of miners. However, they can be used accurately and purposefully only in greenhouses. Effective and reusable spraying of plants with agents containing feverfew.
The imago (final stage of development) of miners can be caught using sticky boards or products containing feverfew. It should be remembered that miners quickly become resistant to all pesticides.
Attention! Pyrethrum-based insecticides are very unhealthy. When working with them, wear gloves and masks to protect your face! Spray either morning or evening when biological enemies such as ladybugs or riders are not active. Do not get close to water bodies.
Natural methods of struggle
Remove affected leaves. Check if the plants have gnawed passages and puncture marks. Cut and destroy the leaves.
Cover with a non-woven cloth. Grow vegetables and flowers under a non-woven fabric so that miners cannot lay their eggs on them.
Spray with spring oil. Oil can be used only for plants with strong leaves.
Let the riders into the greenhouse. You can get them in specialized stores for gardeners.
Insecticide Control Methods
If a mining fly or moth is found, insecticides cannot be used immediately. Effectively spray means containing pyrethrum. However, spraying will have to be carried out several times in a row. Spray from five to six times with an interval of three to five days.
Flies and moths die after a single spray. However, their larvae are more hardy. Insecticides often have no effect on pupae, because in some species the pupation phase occurs in the ground. Some success with very severe lesions brings watering the soil with pyrethrum-containing products.
- Cherry, Pear - Symptoms: mining flies and moths leave behind them gnawed passages from light beige to brown. Help: remove affected leaves; hang yellow planks for catching miners.
- Apple Tree - Symptoms: mining flies and moths leave behind them gnawed passages of serpentine, round and bubble shapes. Help: remove affected leaves; hang yellow planks for catching miners.
- Rhododendron - Symptoms: traces of leaf exhaustion by yellowish-green caterpillars of an azalea moth reaching 1 cm in length. Help: remove affected leaves; spray with feverfew; hang yellow boards.
- Holly Holly - Symptoms: leaf mining flies leave puncture points in the leaves; mined passages left by larvae. Help: remove affected leaves; spray with spring oil; hang yellow boards.
- Rosa - Symptoms: light dots from punctures and twisting gnawed passages left in the leaves by a pink mining moth. Help: remove affected leaves regularly; spray with feverfew; hang yellow boards.
- Zinnia - Symptoms: leaf mining flies leave light beige gnawed passages or spots on the leaves.
- Chrysanthemum - Symptoms: Mining leaf flies leave light, strongly twisting passages in the leaves.
- Violets - Symptoms: whitish spots and gnawed passages appear on the leaves.
Help: regularly remove affected leaves, spray with a preparation containing pyrethrum.
- Salad - Symptoms: on the leaves appear whitish puncture points and gnawed passages that arose when defeated by mining flies.
- Tomato - Symptoms: whitish dots and gnawed passages appear on the leaves.
- Cucumber - Symptoms: on the leaves appear white dots from punctures and traces of gnawing by flies that look like moves.
Help: let the riders into the greenhouse; hang yellow boards.