Flower Aphid Control Methods and Seedling Care Key Points
Flower aphids damage tulips, peach blossoms, cherry blossoms, oleander, plum blossoms, hollyhocks, orchids, cineraria, pansies, pot marigolds, cornflowers, carnations, irises, freesias, lilies, apricots, pomegranates, as well as flowers in the Solanaceae, Brassicaceae, Cucurbitaceae and other families.
Aphids are one of the most damaging pests to flower seedlings (nursery stock); almost every kind of seedling can be harmed by one or several species of aphids. They use their piercing-sucking mouthparts to absorb large amounts of sap from the seedlings, deteriorating their nutrition, stunting or delaying growth, and in severe cases causing deformed growth, inducing sooty mold, and transmitting various plant viruses.
The main aphid species include:
1. Green peach aphid (Myzus persicae): also called peach wing aphid, cabbage aphid, etc. It can damage [plants] and can transmit at least 103 plant viruses.
2. Cotton aphid (Aphis gossypii): also called melon aphid. It can damage tree peonies, salvia, Cucurbitaceae flowers, chrysanthemums, hollyhocks, cockscomb, cineraria, orchids, canna lilies, primroses, tulips, lilies, carnations, cyclamen, hibiscus, roses, Chinese hibiscus, redbud and other seedlings. The cotton aphid can transmit at least 46 plant viruses.
3. Water lily aphid (Rhopalosiphum nymphaeae): can damage lotus, water lilies, plum blossoms, peach blossoms and other seedlings (nursery stock).
4. Chrysanthemum aphid (Macrosiphoniella sanborni): also called chrysanthemum small long-tube aphid. It can damage chrysanthemums, wild chrysanthemums and other Chrysanthemum seedlings. It can transmit at least more than 5 plant viruses.
5. Rose long-tube aphid (Macrosiphum rosivorum): can damage the nursery stock of roses, multiflora roses and other Rosa plants.
6. Apple aphid (Aphis pomi): can damage peach blossoms, Chaenomeles speciosa, hawthorns and other nursery stock.
7. Peach leaf-curling aphid (Tuberocephalus momonis): can damage elm-leaved spirea, plum blossoms, peach blossoms, cherry blossoms and other nursery stock.
8. Peach powdery large-tailed aphid (Hyaloptera amygdali): also called peach powdery aphid, peach powdery green aphid. It can damage peach blossoms, elm-leaved spirea and other flowering trees. It can transmit at least more than 3 plant viruses.
Control methods:
1. Eliminate the source of pests. Clean the greenhouse thoroughly and eliminate overwintering pest sources. For those raising seedlings in flower production greenhouses, strengthen aphid prevention on the growing flowers.
2. Biological control. Use natural enemies such as aphid parasitic wasps, ladybugs, hoverflies, lacewings, spiders and aphid-eating velvet mites for control. Use microorganisms such as aphid fungi that cause disease in aphids for control.
3. Use silver-gray film to repel aphids. Lay silver-gray film strips at intervals on the working paths of the seedbed and around the seedbed; this should be done before sowing or transplanting seedlings. For green peach aphids, yellow boards coated with sticky oil can also be used to trap and stick them; generally the board is 1 m long and 20 cm wide.
4. Chemical control. The key spraying sites are the growing points and the undersides of leaves. Use 1.8% abamectin (Chongmanke) at 3000-5000 times dilution, 10% imidacloprid wettable powder at 2000 times dilution; 50% pirimicarb wettable powder at 1500-2000 times dilution has a special effect on aphids, but poor effect on cotton aphids. Or 20% fenpropathrin emulsifiable concentrate at 2000 times dilution, or 2.5% bifenthrin emulsifiable concentrate at 3000 times dilution, or 25% dimethoate-cypermethrin emulsifiable concentrate at 1500 times dilution, or 40% dimethoate emulsifiable concentrate at 1000 times dilution, or 20% compound liuyangmycin emulsifiable concentrate at 1000 times dilution, or 30% acephate emulsifiable concentrate at 1000 times dilution. Dimethoate and omethoate may cause phytotoxicity to cherry blossoms, plum blossoms, peach blossoms, elm-leaved spirea, Chaenomeles speciosa and other Rosaceae flowers, so they should generally not be used. Dichlorvos causes obvious phytotoxicity to plum blossoms and elm-leaved spirea, and should be used with caution on rhododendrons. Trichlorfon causes phytotoxicity to cherry blossoms and plum blossoms.