Detailed Guide to Pest Control Methods for Four-Season Orchid (Cymbidium ensifolium)

Four-SeasonOrchidPests are more severe than on other orchids. Because its blooming period is concentrated in summer and autumn, when it is hot and dry, its flowers have a delicate fragrance that often attracts many insects to gnaw on the petals and sap. Among them, thrips are the most serious, occurring year-round. The larvae are peach-pink, and the adults are black. About 2mm long, like fleas. Damage is mainly on flowers. It causes brown spots on petals. In severe cases, buds do not open and wither and die. Thrips like to hide at the base of petals and in the leaf sheaths of new shoots. When there are no flowers, they hide in the gaps between pseudobulbs and damage tender shoots. Damage marks are first found when new shoots open, initially as white spots, resembling virus disease symptoms. After the plant matures, they appear brown. They can even cause leaves to wrinkle and distort. These wounds often allow other pathogens and viruses to invade. Next are scale insects and aphids. They can cause damage at leaf bases, leaf blades and flower stalks, and they live symbiotically with ants, specifically sucking plant sap, causing yellow spots on leaves, premature withering and dropping, and they occur almost year-round. Next are leaf beetles, which specifically damage flower buds. Their body color is golden yellow, and body length is 12-18mm. When all flower buds in the orchid garden have been eaten, this insect is no longer found. The control methods for the above pests are the same. When infestation is severe, besides removing flowers, apply pesticide once a week for two consecutive times. Control agents can be any one of omethoate, methomyl, carbosulfan, dimethoate, chlorpyrifos, malathion, permethrin, etc. Mix the dosage according to the instructions. Pests harmful to roots and stems include nematodes and mollusks such as slugs and snails. Among them, burrowing nematodes are the most serious. Besides causing root rot, the growing points of pseudobulbs are also completely destroyed and no shoots grow. Mollusks such as slugs and snails gnaw on new roots and tender shoots. Such animals all share a common characteristic: their skin secretes oil for gliding and breathing. Using degreasing cleaners, soapy water, dishwashing liquid, or natural remedies such as soybean powder and tea seed meal can all achieve good results. Soybean powder and tea seed meal need to be soaked and dissolved in edible vinegar or sugar-vinegar solution, then the liquid is diluted 200 times for drenching or soaking. Chemical agents such as polybutene and Wanqiang can be used for treatment. They are highly toxic and must be used with caution. For pest control, besides active pesticide killing, passive repellence is also a good strategy. For example, hanging green, white or yellow sticky boards or sticky tape can reduce damage from thrips and flying insects. Spreading lime on the ground or covering the support posts of planting beds with plastic bottles can prevent slugs and snails from invading. Sugar-vinegar solution can eliminate red spider mites. Natural organic substances with pungent odors such as wood vinegar, alcohol, garlic juice, chili juice, neem oil, camphor oil and citronella oil are also very effective at repelling insects. Pest control does not require total extermination. After killing one batch, a new batch will still invade from outside. Long-term human exposure to pesticide environments is extremely harmful to health. Adopting organic pesticides and physical control is gradually becoming the mainstream of modern agricultural technology, and there are still many good methods waiting to be developed. (Taiwan, China, Wu Senyuan)