Pine trees and cypress trees are evergreen all year round, with a beautiful shape, and have a certain degradation effect on dust, and have always been tree species often used in landscaping. However, from May to June every year, these two kinds of trees often dry up and die, and as long as it occurs, it will not be one or two trees, but a piece of death.
Most of the friends who do garden maintenance know that most of the causes of the death of pine trees and cypress trees are caused by excessive watering and rotten roots. However, for these trees, the roots were not found to be water. So, what is it that causes their mass deaths?
Careful observation is not difficult to find that these dead trunks are covered with dense holes, the bark is also some loose, open the bark, you will find that there are some regular insect passages below, sometimes there are small insects as large as rice grains, in fact, it is the culprit that caused the death of the whole tree - small silverfish.
[1] Small silverfish hazard characteristics
Hidden hazards: Moth damage under the cortex, forming tunnels, destroying phloem and xylem tissue, resulting in water and nutrients can not be transported and conducted. It is not easy to detect before the tree withers, and when the branches and leaves are yellowed or the whole plant is yellowed, the insect infestation has been seriously occurred.
Group warfare: They invade in groups, endangering weak trees (such as newly transplanted pine and cypress trees, which grow weaker after transplanting, and have not yet fully recovered) The conifers in a weakened state will emit a fragrance themselves, which can lure small silverfish within 30 kilometers to lure them, and they fight in legions and harm at the same time. It can cause a large number of tree deaths in just a few tens of days.
[2] Life history of small silverfish
The small beetle belongs to the Coleoptera family, which is a small beetle, and the main species are pine longitudinal pit cut small beetle, pine horizontal pit cut tip small beetle, cypress skin small beetle and so on. Generally, one generation occurs every year, and adults overwinter, and the wintering sites vary from north to south. In the south, adults overwinter within the infested branches. In the north (Liaoning, Jilin, Shandong) most adults overwinter in the soil around the affected plants. In Liaoning, Shandong and other regions, overwintering adults fly out of late March to mid-April to replenish nutrition on new shoots, and later build pits, mate and lay eggs on healthy treetops, weak trees or wind-fallen trees. The larval stage is about one month, and the larvae begin pupating from late May to mid-June. From May to July, new adults appear, and then invade the new shoots to feed, the adults have the habit of turning the branches, an adult worm can drill several new shoots, and can invade as many as a dozen holes in a branch. Wintering begins in early and mid-October.
[3] Small beetle control method
1. Agricultural prevention and control
(1) Scientific fertilizer management, eradication of weeds, enhance tree potential; (2) winter pruning of affected branches, stems, but also in the first to second generation of adults before feathering to prune dead branches and piles concentrated burning, to prevent their spawning and reproduction; (3) the use of booby traps. The semi-dead branches are tied to the branches or trunks to induce them to lay eggs; the base of some 1-year-old branches can also be peeled off with a knife to create a semi-dead state, luring them to spawn or parasite centralized killing.
2. Pharmaceutical prevention and treatment
The use of Qilin eradication of moth roots to administer control or the use of moth clearing bottles for prevention and control or the use of Guangzheng + Cheng attack for spray control can play a good control effect.
