Basic long-term scientific and technological work project in agriculture: Practical technology for diagnosis and control of pear stem bees in pear orchards
Basic Long-term Science and Technology Work Project in Agriculture (NAES049PP10).
Yan Wentao and others
Pear stem bees, also known as folding insects, bud-cutting insects, etc., with adults and larvae as the pest of pear tree new shoots, especially adult insects as the most serious pest, is an important pest of pear tree spring shoots, affecting the shape and crown of young trees. The insect is mainly harmful to pears, and is distributed in Pear producing areas in China.
1 Field symptoms
When the new shoots grow to 5 to 8 cm, the adults begin to infest, using a saw-shaped ovipositor to serge at the 4 to 5 leaves of the young shoots, and then cutting off the leaves of the 3 to 4 leaves below the wound, leaving only the petiole. The new shoots shrank and drooped after being sawn, drying and falling off. The larvae feed on the remaining tender stem pulp, the worm feces fill the worm body after the worm's body, and the affected young stem later becomes a black-brown branch, which is brittle and easy to fold.
Pear stem bees are harmful to young shoots
Pear stem bees are ovate-like in new shoots
2 Morphological characteristics
Adults are 9 to 10 mm long, with a wingspan of 13 to 16 mm, and are slender, black, shiny, with black filamentous antennae, and yellow on both sides of the anterior and posterior margins, the base of the wings, the posterior thorax, and the feet. The wings are pale yellow and translucent , the veins are dark brown , and the female has a saw-shaped ovipositor in the abdomen. The ovoids are oval, about 1 mm long, slightly curved, milky white, translucent. The mature larvae are 10 to 11 mm long, slightly flattened, white at the beginning of hatching, gradient yellowish, yellowish-brown in the head, upturned tail, and no gastropods. Pupae are pupae, all white, black before feathering, and red compound eyes.
Pear stem bee adult
3 Occurrence
Pear stem bees occur in 1 generation per year, overwintering in the infested branches as old mature larvae. In the following year, the adults of the pear tree flower gradually feather, and the duck pear lays eggs 5 days after the full bloom of the pear. Adults are more active on sunny days 10:00-13:00, flying, mating, laying eggs, and lying still on the back of the leaves on rainy days and in the morning and evening when the temperature is low. When adults lay eggs, they first use a saw-shaped ovipositor to serrate 4 to 5 leaves of the young shoots and lay the eggs in the young tissue 2 to 4 mm below the wound. The spawning period of adults lasts about half a month. At the egg stage of 7 days, the larvae hatch and feed under the branches, and after aging, the head is up into a cocoon to hibernate overwintering.
4 Prevention and control period
Young trees or high-pitched orchards can be sprayed once during the inflorescence separation period to the bell bulb stage (new shoots grow to 5 to 8 cm) and once after flowering.
5 Prevention and control measures
(1) Artificial control. Within half a month after the flowering, the wilted insect shoots at the upper end are cut off in time and destroyed centrally. Combined with winter pruning, the damaged branches are cut off and burned in a concentrated manner.
(2) Timely spray prevention and control. Adult orchards generally do not require spray control, and young tree gardens or pear orchards with high replacement heads do. When the new shoots grow to 5 to 8 cm (inflorescence separation to the bell ball stage) the first spray, the pear immediately after the flowering is sprayed for the second time. Commonly used effective agents are 90% antidovir (fast) soluble powder 3000~4000 times liquid, 4. 5% high efficiency cypermethrin emulsion or water emulsion 1500~2000 times liquid, 5% high efficiency cyfc cyfc permethrin emulsion 3000 ~4000 times liquid, 52. 25% chloryanide chlorpyrifos emulsion 1500 ~ 2000 times liquid, 48% chlorpyrifos emulsion 1200 ~ 1500 times liquid, 40% chlorpyrifos wettable powder 1000 ~ 1200 times liquid, 20% cypermethrin emulsion 1500 ~ 2000 times liquid, etc.
Atlas of pear stem bee control techniques