Termites are very common for ornamental trees in gardens. The harm degree of termites to trees is often related to the age of trees. The older the trees, the higher the damage rate.

Termites that harm garden trees mainly include black-winged soil termites, yellow-winged giant termites, Taiwan milk termites, black-breasted termites, yellow-breasted termites and pointed-lipped termites.

Different kinds of termites do different harm to trees. Lactic termites in Taiwan Province mainly eat xylem, so the damage found on the surface of trees is less, but it is very harmful to trees, and their nests are often built on some trunks or roots. Black-winged termites and yellow-winged termites generally harm the epidermis and cork layer of the trunk first, and then gradually penetrate into the xylem in the later stage. Generally speaking, yellow-winged termites eat deeper than black-winged termites. Reticulitermes flavipectus generally damages the superficial woody layer of epidermis, but it can also penetrate into the xylem in the later stage.

Hangzhou Bureau of Landscape Architecture (1972) and Liu Youfa (1996) summarized the control measures of garden termites:

1) quarantine. In the process of tree migration, termites are often inadvertently carried and spread, so when transplanting trees, on the one hand, we should pay attention to thoroughly treating the remaining active termites before planting; On the other hand, don't choose trees that are seriously damaged by termites, especially trees that have nests of Taiwan's milk termites, so as to avoid the spread of termites.

2) Eliminate winged adults and prevent the emergence of new groups. The winged adults in the colony are the founders of the new colony and fly alone from April to July every year. In the meantime, we can use phototaxis and set up lights to trap and kill.

3) Protect natural enemies.

4) Eliminate the breeding ground of termites in the garden. There are often some dead trees, dead roots, stumps and sticks in the garden that are placed in the open air for a long time, which are easy to rot after being wetted, and become the favorite material of termites, which has a certain attraction to termites and must be removed.

5) Avoid mechanical damage to trees. Wound is the main entrance of termites, so avoid causing big wounds in pruning, shaping and other operations, and do not cause mechanical damage in human activities such as intertillage and soil preparation. The wound that has formed should be protected by anti-ant chemicals, and then coated with cedar oil.

6) plug the hole and repair the wound. Some big trees will have cavities or big wounds, so it is necessary to brush anti-ant drugs in time, and then use cement gravel or cement mortar to block and repair them, which is both beautiful and can prevent termites from invading.

7) medication. Using 10 diluted 50% chlordane emulsion solution or 9202 (mixed solution of lesburn) to coat the near-ground part of trees has certain effect on preventing and controlling the harm of black-winged soil termites and other trees; In addition, ditching between seedlings and spraying 2% chlordane powder have certain effects on preventing cutting wood from being harmed by termites.