Leafminer moth
Citrus leafminer moth, belonging to lepidoptera, leafminer moth family, is one of the most important pests in the young shoot stage of citrus, generally in the summer and autumn shoots are more seriously affected, and the spring shoots are lightly affected. Because the larvae will dive into the leaf flesh on young leaves, young stems and even under the surface of the fruit, leaving irregular silver-white lines, the leafminer moth is called "ghost drawing symbol" and "drawing worm" by fruit friends.
<h1 class="pgc-h-arrow-right" >01. Hazard characteristics</h1>
Citrus leafminer moths like to harm young tissues, specifically like to "wriggle" between the upper and lower cortex of young shoots and young leaves, causing the affected leaves to shrink and deform.
Finally, the new leaves are rolled into a cylinder, and the original flattened leaves are rolled up, and their photosynthesis will be directly affected, resulting in early shedding of the leaves.
The growth of the entire canopy will also be hindered by the normal photosynthesis of the leaf surface, and eventually the crown will not grow high.
In addition, the leaves endangered by leafminer moths are often the wintering sites of other pests, and the various wounds caused by them are very easy to cause ulcer disease, and it can be said that the "stop" of leafminer moths has created conditions for citrus canker disease.
<h1 class="pgc-h-arrow-right" >02</h1>
From late April to early May, the larvae begin to harm, and July to September is the peak of the occurrence period, and the harm is also serious. The occurrence is the most decreased after October. It takes about 20 days to complete the generation. Adults mostly feather in the early morning, inhabit the leaf back and weeds during the day, are active at night, and are phototropic. Eggs are laid in the evening of the second to third day after mating, and the eggs are mostly laid near the midrib on the back of the young leaves, and can be produced several grains per leaf. Each female can lay 40-90 eggs, with an average of about 60 eggs.
After the larva hatches, it sneaks under the leaf epidermis from the bottom surface of the egg, eats the leaf flesh inside, and advances while eating, gradually forming a curved worm path. When ripe, most of them moth to the leaf margin, in which the insect body spits a thin cocoon to pupate, often causing the leaf edge to curl up. Seedlings and young trees, due to the large number of shoots and not neat, are suitable for adult egg laying and larval damage, and are often more seriously affected than adult trees.
<h1 class="pgc-h-arrow-right" >03</h1>
(1) The temperature in winter and spring is low, the mortality rate of overwintering insects is high, and the population of leaf-diving moths is small, so the spring shoots are almost harmless; the summer shoots of hanging fruit trees will be controlled, often less affected, and the temperature in autumn is moderate, the amount of shoots is large, and the damage is often serious.
(2) Prevention and control can not be sprayed in time for prevention and control, farmers often find that there is harm before taking drugs, it is more difficult to control the damage caused to the leaves. In particular, the newly planted young trees are not medicated in time, which affects the growth of saplings. At the same time, because of its wounds, it is easy to cause ulcer disease.
(3) Seedlings and juvenile trees are often more affected than adult trees because they do not control their shoots and control their shoots, allowing the branches to grow freely and overgrown with weeds, which are suitable for adult eggs laying and larval harm.
<h1 class="pgc-h-arrow-right" >04</h1>
1. Agricultural prevention and control:
(1) Clearing the garden to remove insects. Combined with the pruning of the garden after harvesting, the insect leaves and insect shoots on the trees are cut, the dead branches and leaves of the ground are picked up, the lichen and moss on the trees are scraped off, and the upper parts are taken out of the garden for harmless treatment. During the activity period of leaf diving moths, they often clean the weeds around orchards and nurseries to block the holes in the tree body in time.
(2) Put the stalks
Sporadic occurrences of infested larvae and pupae are removed in spring and early summer to reduce the source of insects for the next generation. In the summer and autumn of citrus, control the water and fertilizer, take the "to zero and leave the whole, go to the early stay, concentrate on the shoots" measures to break the food chain, so that the summer and autumn shoots are pumped neatly, in order to reduce its harm and reduce the number of sprays. The obliterated late autumn shoots, winter shoots and dead branches are burned in a concentrated manner.
2. Biological control
Protection and use of natural enemies: While using chemical pesticides, pay attention to the protection and utilization of natural enemies of citrus leafminer moths such as grasshoppers, white star wasps and predatory ants, because parasitic bees and other natural enemies are mostly feathered in the morning, so the spraying time is best chosen in the afternoon or evening.
3. Chemical control
Using [Kang Huan], the insect eggs are killed at the same time, and the effect is good.