Prevention and control of flower aphids

Aphids belong to Homoptera and Aphididae. It has the advantages of small body, strong fecundity, complex and diverse hosts and long damage period. it is also the main vector for the transmission of viral diseases, so it must be prevented and controlled as soon as possible. There are many kinds of aphids that damage flowers, sometimes singly and sometimes mixed. The main species are (1) cotton aphids, also known as greasy insects, omnivorous pests distributed all over the country, mainly harmful to mulberry, hollyhock, hibiscus, orchid, rose, pomegranate, carnation, lily, chrysanthemum, begonia, camellia, cyclamen and other flowers. It occurs more than 20 generations a year, overwinters with eggs, hatches when the temperature rises to more than 10 ℃, first harms the overwintering host, produces winged migration aphids after 4 generations, migrates to summer hosts from April to May, migrates to overwintering hosts in October in September, and produces winged male aphids and wingless female aphids in November, mating and laying eggs. (2) Spiraea chrysanthemum aphid, also known as apple aphid and apple yellow aphid, mainly harms many kinds of flowers and trees, such as cherry blossom, hydrangea, Spiraea, tapetum, begonia, gardenia, sweet-scented osmanthus, elm-leaf plum, white orchid, peach and so on. More than 10 generations occur every year, overwintering with eggs in the tender shoots and crevices of annual branches. It began to hatch in late April and propagated rapidly from June to July, causing serious damage. At this time, a large number of winged female aphids were produced and transferred to other plants. From August to September, the number of sexual aphids decreased gradually. Sexual aphids were produced in November and spawned and overwintered. (3) Peach aphid, also known as red aphid and tobacco aphid, mainly harms more than 300 species of plants, such as orchid, cherry blossom, hollyhock, marigold, asparagus, jasmine, canna, peony and so on. 10 Mel 30 generations occur every year, overwintering with eggs in twigs and bark cracks, hatching in March of the next year, and parthenogenetic reproduction. Rapid reproduction from May to June is harmful, and winged aphids are produced in October, mating and oviposition. (4) APHIS gossypii is mainly harmful to rose, rose and other flowers. 20 generations of adult aphids and nymphs overwintered in the leaf buds and dorsal leaves of rose, and the peak periods of occurrence were from May to June and October. A dry climate can lead to a major occurrence. (5) Rhopalosiphum aphids are widely distributed, mainly harming lotus, water lilies, plum blossoms, peaches and so on, and occur for many generations throughout the year. In winter, eggs overwinter on drupe trees such as peach, plum, apricot and cherry. The eggs hatch in March of the following year, and the damage is serious from April to May. The weather is muggy in autumn and less rain is conducive to reproduction. The damage is generally characterized by adult and nymph aphids feeding on host buds, new shoots, flower buds and leaf sap, resulting in slow plant growth, leaves yellowing, wrinkling, curling, reducing the number of flowers, seriously causing plant wilting and even death. at the same time, it can also induce a variety of plant diseases, such as peach aphid excreta often induce coal fouling disease, spread virus disease. Prevention and control methods (1) agricultural control. Weeds on the edge of the field are often eradicated in winter and spring, and omethoate is sprayed to eliminate aphids on overwintering hosts and reduce insect sources. (2) biological control. Protection and utilization of natural enemies, the main natural enemies are predatory ladybugs, lacewings, spiders, aphid flies, aphid cocoon wasps, insectivorous bugs and so on. (3) spraying 2000 times of 50% aphid spray ultra-fine wettable powder or 1500 times of 20% methomyl EC, 1000 times of 50% aphid pine EC, 2000 times of 50% phoxim EC and 1000 times of 80% dichlorvos EC in time after hatching and damage period.

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