What to Do When Flowers Have Aphids? Detailed Control Methods

Aphids belong to the order Homoptera, family Aphididae. They are small in size, highly reproductive, have complex and diverse hosts, and a long damaging period, and they are also the main vector for spreading viral diseases, so they must be controlled early, continuously and thoroughly. There are many species of aphids that damage flowers, sometimes occurring singly and sometimes mixed. The main species are (1) the cotton aphid, also called the melon aphid, a polyphagous pest distributed throughout the country, mainly damaging hibiscus, hollyhock, rose of Sharon,orchids, roses, pomegranate, carnation, lily, chrysanthemum, crabapple, camellia, cyclamen and several other flowers. It produces more than 20 generations a year, overwinters as eggs, and hatches when the temperature rises above 10°C the following year, first damaging the overwintering host; after 3-4 generations it produces winged migratory aphids, which migrate to summer hosts in April-May to cause damage, then migrate to overwintering hosts in September-October to continue reproducing and damaging, and in November produce winged males and wingless females, which mate and lay eggs. (2) The spiraea aphid, also called the apple aphid or apple yellow aphid, mainly damages cherry blossoms, hydrangea, spiraea, Chaenomeles speciosa, Malus spectabilis, gardenia, osmanthus, flowering almond, Michelia alba, flowering peach and many other ornamental trees and shrubs. It produces more than 10 generations a year, overwintering as eggs in the tender tips of annual branches and in branch crevices. Hatching begins in late April, and it reproduces rapidly in June-July, causing severe damage; at this time it produces large numbers of winged parthenogenetic females that move to other plants, the number gradually declines in August-September, and in October-November sexual aphids are produced, which mate and lay eggs to overwinter. (3) The green peach aphid, also called the red aphid or tobacco aphid, mainly damagesorchids, cherry blossoms, hollyhock, marigold, asparagus fern, jasmine, canna, peony and more than 300 other plant species. It produces 10-30 generations a year, overwintering as eggs in tender branches and bark cracks, hatching in March of the following year to cause damage and reproducing by parthenogenesis, reproducing quickly and causing severe damage in May-June, and producing winged aphids in October, which mate and lay eggs. (4) The rose long-tube aphid mainly damages roses, Rosa multiflora and other flowers. It produces 10-20 generations a year, overwintering as adults and nymphs in the leaf buds and on the undersides of leaves of roses, with peak occurrences in May-June and September-October. Dry climate can lead to major outbreaks. (5) The lotus aphid is relatively widely distributed, mainly damaging lotus, water lily, plum blossom, flowering peach and others, producing multiple generations throughout the year. In winter it overwinters as eggs on stone fruit trees such as peach, plum, apricot and cherry; the eggs hatch in March of the following year, damage is severe in April-May, and stuffy autumn weather with little rain favors its occurrence and reproduction. Damage characteristics: adults and nymphs generally gather in groups to suck sap from host tender buds, new shoots, flower buds and leaves, causing slow plant growth, yellowing, shriveling and curling of leaves into clumps, and a reduced number of flowers; in severe cases it causes plant wilting and even death, and it can also induce the occurrence of various plant diseases, such as the excrement of the green peach aphid often inducing sooty mold and spreading viral diseases. Control methods (1) Agricultural control. In winter and spring, often remove weeds from field edges, and spray omethoate to eliminate aphids on overwintering hosts, reducing the source of the pest. (2) Biological control. Protect and utilize natural enemies; the main natural enemies include predatory ladybugs, lacewings, spiders, hoverflies, aphidid wasps, predatory bugs and others. (3) After the overwintering eggs hatch and during the damage period, promptly spray 50% pirimicarb ultra-micron wettable powder at 2000 times dilution, or 20% methomyl emulsifiable concentrate at 1500 times dilution, 50% menazon emulsifiable concentrate at 1000-1500 times dilution, 50% phoxim emulsifiable concentrate at 2000 times dilution, or 80% dichlorvos emulsifiable concentrate at 1000 times dilution. Yufang