When we find that there are many dense 1-3 mm-sized insect holes on furniture or tree trunks, many people immediately realize that this is an insect, but what is this insect and how to control it? This is one of the drill heartworms: small beetles, let's talk about the occurrence and control of small silverfish.
Small beetle insects Coleoptera microfinchaceae. Small beetles are known as the world's forest borer dried pests, because of its fast reproduction rate, hidden activities and other characteristics, this type of pest has become an agricultural economic forest, garden trees, forest trees to overcome the problem of prevention and control. In addition to harming various trees, including dead trees, trunk trees, and weakened trees, small beetles also harm furniture, building materials and decorative wood products.
1. Morphological characteristics of small beetles: eggs: oblong oval, about 0.5mm in diameter, milky white at the beginning, pale yellow before hatching; larvae: larvae are generally about 3.6mm long, milky white, slightly smaller at the front end, slightly hypertrophied at the rear end, wrinkled chest and foot degeneration, abdominal foot marks; pupa: general female pupae are about 2.5mm long, the early milky white, gradually become yellowish brown; adults: male adults are about 1.4mm long, yellowish brown, the surface of the Coleoptera is rough, and the dots and furs are not clearly arranged. The female adult is about 2.5 mm long, cylindrical all over black-brown, with carved dots and fur on the wings, arranged in longitudinal rows.
2. Life habits of small silverfish: algebraic occurrence of small silverfish, generally 1-2 generations occur in 1 year in the north, 3 generations in 2 years or 2 generations in 1 year in high temperature years, and 5 generations in Guangdong and Guangxi in 1 year. From March to May and from September to October of each year, adult worms are in full bloom, during which they fly out of the borer holes in batches after light rain and begin new moth influx. Adults overwinter mainly in the moth tunnel, but some larvae and pupae overwinter. After the temperature rises in mid- and late-February of the following year, the overwintering adults go out to move and moth the trunk to form new moths, and begin to lay eggs in early April. After feathering, the adult worm drills out of the moth tunnel after 7 days, and after the hole, the adult worm mostly resides in the leaf marks and forks of the 1-2 year old branches, forming a moth path, the borer hole is round, about 2 mm in diameter, and the orifice often has wood chips accumulation. It takes 10 minutes to 3 hours for adults to fly out to re-invade the tree, and 10-35 hours from invasion to completion of the moth, which can reach as deep as the xylem. The eggs are laid in the tunnel, the time medicine is about a week, the larvae live in the tunnel, and the adults gradually pupate in the moth, which lasts about 5 days, and generally begins to overwinter in late November.
3. The harm of small beetles:
3.1 There are two main families that endanger home decoration building materials: the whitefly family and the beetle family, the adult body length of the whitefly family is about 3mm, and the diameter of the harmful furniture-like opening is about 1-2mm, round, and a large amount of powder is discharged every day during the hazard. In the family Burglaridae, the adult body is about 5 mm long, the diameter of the opening of the harmful furniture is about 3 mm, and no powder is discharged. The carrying of building materials for interior decoration, especially the lining of wooden floor shelves, furniture and parapet panels, is the main way to spread adult silverfish or eggs. After these silverfish enter the furniture with the building materials, they rely on the cellulose, starch and sugar in the building materials to grow, hatch in the right environment and temperature, and the damage to furniture and wooden structures is more serious after spread.
3.2 Small beetles that endanger trees: The insect hides in the trunk of the tree for life, multiplies countless times, and only briefly flies away from the tree after feathering, and builds another tunnel to invade the new tree, which is long and serious. The harm of insects in the family Beetle family to trees can be divided into bark small beetles and dried beetles according to the parts of their tunnels. Take the bark of the small silverfish as an example, the worm drills the pit in the bark (between the phloem and the xylem), in a flat structure, adults and larvae eat the edges of the phloem and xylem of the branches, through the drill moth as a pest of the phloem, some even damage the tree channeling tissue to cause the tree body to weaken, seriously causing tree death. Dried beetles, on the other hand, mainly harm the xylem, and dry up after being harmed in the body of the tree, unable to transmit nutrients.
4, the occurrence of small silverfish factors: human factors: the selection of seedlings is not qualified, maintenance and management is not in place, not to do active prevention, often the main reason for the occurrence of small silverfish. Failure to nurture and clean up a variety of weak woods in a timely manner can contribute to the spread of this pest. Tree growth and other factors: insufficient fertilizer, water, weak tree growth, or too much dry hot wind and heavy snow caused by large areas of forest wind collapse, wind folding, root system shaking; drought, frost damage, rainy water, groundwater level is too low or too high; dry, hard, poor air permeability, stinging pests or diseases, etc. lead to tree growth decline, resulting in serious harm to small beetles. Harm to furniture: mainly caused by the use of decoration materials to carry small beetle eggs or larval adult worms.
5. Control of small beetles:
5.1 The prevention and control of furniture small beetles: the prevention and control of furniture small beetles, or to prevent the main, that is, when making furniture, the materials are treated in advance to avoid the recurrence of small silverfish after the furniture is made, method one: high temperature method, that is, when dealing with building materials degreasing, the use of steam high temperature deestrification method, so that both building materials can be deesterified, and can effectively kill the adult insects and eggs of the beetles, playing a role in killing two birds with one stone. Method 2: Chemical control, the wood material before use is uniformly stacked, and then sprayed with a compound preparation of permethrin insecticide and organophosphorus insecticide, and then wrapped with plastic film and fumigated to achieve the purpose of killing small beetles. For small beetles found in the furniture that have been used, this method is also used to fumigate the agent, but during this period and after taking the medicine to remove the package, people cannot live in the room, so as to avoid the problem of personnel poisoning.
5.2 Control of small beetles on trees:
Agricultural control: strengthen water and fertilizer management, on the basis of applying sufficient base fertilizer, rational fertilization at the shoot stage, promote the growth of new shoots, reduce the harm of small beetles, after fruit picking to winter, combined with fruit tree pruning and winter garden clearance, pruning insect pest branches, for seriously damaged fruit plants, the implementation of heavy fertilization, heavy pruning, and reduce the source of insects to make the tree body renewed and strong.
Bait tree booby trap: When the insect rate is less than 2%, bait wood booby trap can be set.
Pharmaceutical control method: spraying medicine control at the base of the trunk, removing weeds around the base of the trunk, sprinkling octyl thion and other organophosphorus insecticides can be wet powder, and then turning over the tree tray to kill overwintering adults; prevent seedling diseases and insect pests in advance, avoid tree weakness, so as to achieve the purpose of preventing small beetles; tree trunk drug control, spray "xiu sword package" on the trunk, but can not spray to the leaves, to achieve the purpose of killing small beetles. If there is also insect infestation on the small branches (can not be sprayed to the leaves), then use acetamiprid, chlorpyrifos compound preparation 600 times, and then with propromophos and octylthion compound preparation 800 times spray the whole tree, three times continuously, at an interval of 7-10 days; or use aluminum phosphide after the plastic film wrapped in dry fumigation, to achieve the purpose of killing small beetles.