• Categories: Peach aphid (smoke aphid), radish aphid (aphid), kale aphid
• Kale aphid: It is a pest in the north and is the dominant species in Xinjiang.
• Peach aphids and radish aphids are widely distributed and often mixed.
• Spring vegetables are mainly peach aphids, autumn vegetables on peach aphids and radish aphids both, but the latter is the mainstay.
peculiarity:
• Adult insects and aphids are clustered on the back of the leaf and the heart of the leaf spines to suck sap, so that the leaves shrink and turn yellow, so that the stems and peduncles are twisted and deformed, and the plants are short or even dead. When it is serious, the outer leaves collapse and wither, which is called "collapse gang", so that the vegetables cannot be wrapped, which seriously affects the yield and quality of vegetables.
• Excrete a large amount of honeydew, which incurs mold parasitism and forms a "coal pollution disease".
• Transmission of a variety of viral diseases, tobacco mosaic virus disease is transmitted by peach aphids; as long as each rapeseed has 2 poisonous aphids smoked for 5 minutes, it can make healthy plants sick;
• Peach aphids and radish aphids have a common seasonal growth type, that is, spring and autumn are heavy and summer is light.
Peach aphids
Yellow-green, brown at the apex,
Radish aphids
The apex is constricted, the base is semi-green, and the terminal half is black.
Kale aphid
2.2.2 Habits of life
a. The reproduction rate is fast and the generation cycle is short. If the aphid develops into an adult aphid after 6 to 7 days, it begins to reproduce and reproduce offspring of parthenogenesis, and the generation overlap is serious;
b. Wingless female aphids are clustered in the young green parts of the host for harm: radish aphids are mostly clustered on vegetable heart leaves and inflorescences; peach aphids like to gather on the back of the bottom leaf and on the outer leaves.
c. Tendency
l Positive tendency
Ø The three kinds of aphids have a strong tendency to yellow and orange, followed by green. - Yellow dish to lure aphids.
Negative tendency
Ø All three species of aphids have a negative tendency towards silver gray. ——Seedlings can be covered with a silver-gray plastic film mesh to achieve the purpose of early aphid avoidance.
d. From spring to autumn, three species of aphids continue to spread in the field. Trophic mutagenesis and density mutagenesis are important factors in the formation of winged aphids.
E. Aphids are most sensitive to light. Generally take off during the day and do not take off at night, there is a chemotic reaction to light with a wavelength of 550 to 600 nm.
2.3 Occurrence of relationships with the environment
2.3.1 Climatic conditions: Warm and dry conditions are suitable conditions.
(1). Temperature
Compared with other insects, it has the characteristics of strong low temperature resistance, low starting temperature of development and short completion of a generation. For example, the starting temperature of the development of kale aphid is 4.3 °C, and the effective accumulated temperature is 112.6 °C.
The suitable temperature required for cabbage aphid is 20 °C ~ 35 °C, radish aphid is 15 °C ~ 26 °C, peach aphid is 24 °C, so the local generally in late spring, early summer and autumn is the most serious period of aphid pest.
(2). Humidity
Aphids generally grow and develop between 50% and 85% of the relative humidity, and have an inhibitory effect on aphids when it is higher than 90% or less than 40%.
When the humidity is too large, it is easy to occur aphid mold disease, which occurs lightly. Long-term rainy weather also often leads to the occurrence of aphid mold, and its effect on controlling aphid volume is more obvious.
Rainfall has a scouring effect on aphids. Rainfall is also an important factor limiting the occurrence of aphids. Especially in the event of heavy to heavy rains, strong mechanical scouring causes a sharp drop in aphid volume.
Dry seasons and dry areas occur heavily.
2.3.2 Host plants
a. Different crop species affect the structure of mixed populations;
b. Different varieties have different insect resistance: kale aphid prefers to have thick leaves, hairless or hairless leaves, and waxy species such as kale, cauliflower, etc.; Radish aphid prefers species with hairy leaves and less waxy, such as radish, cabbage, etc.
2.3.3 Cultivation conditions and topography
The occurrence of manure is heavy; the height of the terrain is heavy.
2.3.4 Predators
a. Predatory: ladybugs, grasshoppers, aphid-eating flies, spiders
b. Parasiticity: aphid cocoon bee, aphid wasp
c. Pathogenic microorganisms: aphid mold, insect mold
2.4 Prevention and control measures
2.4.1 Agricultural control
a. Reasonable planning of pastoral: reasonable selection of seedbeds, do a good job of intercropping and planting.
B. Improve cultivation technology: selecting aphid-resistant varieties, sowing aphids at the right time, and choosing an appropriate sowing period are favorable measures to prevent aphid infestation.
C. Clean the garden: prune the branches and leaves to remove aphids, remove the bottom leaves and old leaves with aphids, make the inter-row ventilation and light, and reduce the occurrence of aphid infestation.
2.4.2 Physical and mechanical control
a. Silver gray film to drive around: cover the seedbed with silver gray reflective plastic film;
b. Yellow dishes or yellow plates induce aphids.
2.4.3 Pharmaceutical control
a. Control indicators: the aphid plant rate reaches 10% or the average plant has 3-5 aphids. In areas where the virus is endemic, 1-2 winged aphids per plant are controlled.
b. Prevention and control period: before the emergence of winged aphids and the spread of migration
c. Medication: imidacloprid, acetamiprid
d. The nozzle should be upwards, focusing on the reverse side of the blade.