When caring for orchids, pests are almost inevitable. It can be noticeable in the greenhouse as well as in the plant window or at another location, often without one being able to explain the cause. On closer inspection, however, it turns out, that the plants were weakened by improper treatment and thus the natural defenses could not be active to the necessary extent. A plant, which grows in a completely appealing environment, will hardly show any damage, unless, animal or fungal pollutants have been introduced and have spread undesirably. Regular control of the plants is important, as early detection facilitates control. Fortunately, there are relatively few pests and diseases.
Aphids occur on young, occasionally soft shoots; they are green, very agile and soft, as a result, easy to combat.
Grease- or lice are recognizable by their white woolly protective substance. The animals thus protect the eggs and the young. A safe fight is through mechanical cleaning of the hiding places, by brushing out more often, possible. Spritz- or dusts are mostly ineffective, because they do not penetrate the protective layer. At best, one can counteract spreading with a sharp jet of water.
Scale insects can be very uncomfortable. They are only mobile when they are young and then relatively easy to fight. As soon as they have established themselves in a suitable place, hardens the shield, and common pesticides fail. Here, too, mechanical cleaning with a brush or paintbrush is the safest means of destruction. Spray at intervals of 4-8 Weeks still destroy soft young animals, so that, with a little attention, these dreaded polluters can also be kept under control or completely destroyed. If the plants are neglected, the scale insect infestation can be devastating and cause complete loss. Hard-leaved orchids are preferred, wie Catt-leya, Cymbidium, Bifrenaria, Lycaste, Odontoglossum, Oncidium, Wanda u. a.
Spider mites are much smaller, difficult to identify harmful agents and therefore particularly dangerous. The so-called red spider is with Dendrobium, Phalaenopsis u.a. soft-leaved orchids feared. The underside of the leaves in particular is where the tiny, reddish animals reside. Due to the infestation, the leaves initially turn gray, then yellow-brown color and finally fall off. Moist air and not excessive heat reduce the spread, preventive sprayings at more frequent intervals completely prevent them. Sometimes it is necessary to change the spray agent, because with constant use of a single resistant strains of the damaging agent can develop. Are only single plants present, so the more frequent careful washing of the leaves is sufficient as a preventive measure. Insufficient humidity is the main cause of an infestation.
Soft skin mites, frequently observed on other plants, can by sucking on the flowers- or leaf buds of Paphiopedilum cause crippling or stem deformation. These pollutants can be easily combated with an appropriate spray.
Bladder feet (Thrips), also very small, from black to pale yellow in color, damage by sucking on the leaves, Flower buds or flowers. The flowers are brown-spotted or crippled, the leaves are pale, shimmering silver or cork-like discoloration.
Root mites occur secondarily on weak ones, ailing plants. They eat up the roots inside and thereby destroy them. Control by hosing the roots when transplanting with a sharp jet of water and then immersing them in a broth, how it is normally used for mite control.
Snails – namely nudibranchs and small snails – are among the most frequently identified damage to root tips, young shoots, Buds and flowers. They can cause serious disappointments, because they usually remain unobserved and destroy the happy expectations of flowering successes in one night. Controlling the plants in the dark and reading the animals is a surefire means of destruction. The snail baits on the market require a check the morning after they are laid out, since the animals are only unable to move and recover after a few hours; they must be collected in good time. Wood lice are particularly damaging by eating at the root tips, whereby the plant can eventually be completely destroyed. To give the animals as little shelter as possible, is the first commandment to combat. So meticulous cleanliness! Under laid out potato slices, the undersides of which are slightly hollowed out, the animals gather, so that they can be read and destroyed.
Ants cause secondary damage, because they carry scale insects from one plant to another. Commercially available preparations for combating are possibly. only partially effective. Fruit leftovers or other foods accepted by ants, like bread, Meat etc., act as bait and enable their destruction.