How to Treat Pest Infestations? An Introduction to Practical Control Methods

All flowering plants contain nutrients that can be fed on by different kinds of insects,orchidsare no exception.Orchidpests fall into two categories: those that harm orchid leaves and those that harm orchid roots. Pest control should be based on prevention: with sufficient sunlight, appropriate moisture, a well-ventilated environment, and robust plant growth, pests will find it very difficult to cause damage; otherwise, the opposite is true. We should also master some basic knowledge of pest control. Among the pests that harmorchids, the main ones on the upper surface of the pot are scale insects. They fall into two types: one is armored scale. In the larval stage, extremely tiny bodies can be seen with the naked eye wriggling in the "V"-shaped area at the leaf base, but they quickly form a waxy covering and attach themselves in the shaded area at the leaf base, using needle-like sucking mouthparts to draw leaf sap, causing the scale to expand, the insect body to grow, and the scale covering to thicken. If discovered relatively late, this pest will cover the entire leaf base of the pot. This type of scale insect is relatively difficult to kill; dimethoate (Leguo) is quite effective, but it is highly toxic, and the person applying it must take protective measures. Based on recent practice, "Huakang No. 1" produced by Sichuan Chengdu Huayi Company is quite effective at killing scale insects (and is effective against many kinds of pests). After killing the insects, for the sake of appearance, the waxy shells should also be scraped off. It should be noted that after a certain period of time, the waxy shells will also fall off on their own. The other type is mealybugs, which often appear as white cotton-like masses attached to the base of the orchid plant; when pressed with a finger, a bright red blood-like substance oozes out. This pest reproduces quickly, and on a moist pot surface, it can appear in large numbers at the base oforchid plantswithin three to five days. Spraying with omethoate or trichlorfon two or three times will kill them. Besides scale insects, mites are also commonly seen. These pests are extremely likely to occur wherever the orchid growing area is not clean and hygienic enough. Because mites can crawl, they quickly infest the entire plant, causing especially severe damage to new growth at the base. When treating them, a hose-type sprayer should be used to evenly spray trichlorfon, trichlorfon-mite acid, etc. on the pot surface and both sides of the leaves; the pot body and pot stand should also be sprayed to prevent escaped mites from reproducing. Aphids also harm orchid leaves. Aphids generally occur mostly during the overly humid plum rain season. The damaged areas are mostly at the tips of the orchids. Because aphids have green protective coloration, they must be inspected frequently to be discovered. Aphids are stubborn pests, and ordinary pesticides find it very difficult to eliminate them completely; according to observation, malathion, derris extract, lindane, and omethoate are relatively effective. "Huakang No. 1" is also the first-choice pesticide. Wherever there are many ants on orchid leaves, there are sure to be aphids. Slug and snail damage mostly occurs during consecutive rainy and humid weather. On dark, unlit nights when the orchid growing area has poor ventilation, these pests crawl in the orchid pots and chew on tender plants, directly harmingorchid plantsand also causing contamination. These two pests hide by day and come out at night, so spraying liquid pesticide is not very effective; scattering carbofuran on the potting medium can prevent their damage. Although rats are not pests, they also cause damage in early spring and during the flowering period, eating only tender shoots and flower buds. To eliminate rats, one must not keep cats; contact with cat urine will inevitably cause young orchids to wither, and cats in heat run and jump about, very easily knocking over orchid pots. The best way to eliminate rats is to scatter carbofuran once a month around the orchid growing area. Scattering carbofuran can also prevent snakes and toads; sprinkled on the pot surface, it can also eliminate ants and soil pests. It is an extremely simple method. For soil pests such as nematodes, earthworms, centipedes, mole crickets, and ants, the best approach is to scatter carbofuran on the pots; the pesticide seeps into the soil with watering and kills them. To deal with pests, it is best not to use soil as agrowingmedium, not to plant Selaginella uncinata, and not to use organic fertilizers. Of course, if conditions allow the establishment of an orchid growing operation with all facilities in place, using orchid soil to grow orchids is not ruled out either, because this has several hundred years of experience behind it; using soil and broken tiles to propagate orchid seedlings is still good. (Guan Wenchang, Zhu Hexing)