Citrus leafminer moths are also known as leafminers, mapworms, ghost markers, and orange moths. Leafminer moth is one of the main pests that harm citrus shoots and is common in citrus producing areas throughout China.
<h1 class="pgc-h-arrow-right" data-track="18" > symptoms</h1>
The use of larvae to feed on the leaf flesh, resulting in silvery-white meandering tunnels, weakening leaf photosynthesis, affecting the fullness of new shoots, becoming a hidden field for other small pests, and increasing the chance of infection of citrus canker bacteria.
As temperatures have gradually warmed up and autumn shoots have been pumped out in large numbers, the incidence of leafminer moths has reached its peak.
Once the leafminer moth erupts, it does not take a few days to drill the young shoots into a mess, and the affected leaves shrink or harden, which is easy to fall off. In particular, more occurs on seedlings and young trees, which seriously affects their growth.
Of course, the harm of leafminer moths is not limited to new shoots, but also brings a lot of problems to subsequent management.
The wounds caused by leafminer moths on the leaves and branches will make canker disease more likely to invade, and its harmful leaves will provide wintering and settlement places for pests such as mites, resulting in a high pest base in the coming year.
<h1 class="pgc-h-arrow-right" data-track="8" > second, morphological characteristics and occurrence</h1>
It belongs to the order Lepidoptera, tangerine moth family, occurs about 9-15 generations a year, overlaps generations, and mostly overwinters in the autumn and winter leaf margins.
The peak period of leafminer moth occurrence coincides with the large number of citrus summer and autumn shoots, which begins to be harmful from the summer shoots in early June to the autumn shoots in early October, and the most harmful is in August to September. The optimal temperature for reproduction is 24 to 28 °C, and the relative humidity is about 80%. After the larvae harm the young leaves and young branches, the leaves are curled and hard and brittle and fall off, the growth of the new shoots is hindered, affecting the tree posture and the results of the shoots, and the wounds of the larvae are conducive to the invasion of diseases and insect pests such as canker diseases and mites.
<h1 class="pgc-h-arrow-right" data-track="19" >3. Prevention time and method</h1>
1. Inhibit the source of insects
In winter, the garden is cleared, the overwintering larvae or pupae on the young shoots are pruned and destroyed, the dead branches and leaves and weeds are swept away and destroyed, the pest overwintering site is destroyed, and the source of overwintering insects is reduced; in the spring and early summer, the leaves of sporadic larvae or pupae are removed and destroyed to reduce the source of insects in the orchard.
2. Management measures for release
Adopt the principle of "leaving early, leaving zero, and unifying the ends", remove the young shoots that are unevenly ejected prematurely or too late (especially the summer and autumn shoots), and when most buds germinate, the branches are uniformly released, and the food chain of the pest is cut off, thereby reducing the density of the insect population.
3. Pharmaceutical prevention and treatment
In the unified release period, when the new shoots are 5 mm long and the germination rate is about 20%, spray protection immediately, and spray once every 7-10 days after that, 2-3 times continuously.