Privet, Privet, Golden Leaf Privet, Water Wax and other seedlings of the genus Privet in the family Pycnogene have been widely used in landscaping projects, but in recent years they have been plagued by ash bugs.
Meet the ash bug
Ash bugs, commonly known as ash worms, belong to the family Offinch in the family Homoptera. In Jiangsu, ash beetles generally occur in one generation a year. Ash bugs are reddish-brown, spherical fertilized females that overwinter on the branches of the host plant. In March of the following year, with the flow and budding of the sap of the host plant, the female ash borers gradually expanded, usually starting to lay eggs in early April and reaching their peak spawning period in May. Mid-to-late June is the peak of ash bugs, mid-July is the peak of ash bugs, late September is the peak of ash bug pupae, at the end of September will appear ash bug adults, and early October is its peak insect period. Male adults die after mating in early October, while fertilized ash crayfish female adults overwinter on the older branches of the host.
Ash bugs have needle-like sucking mouthparts that suck nutrients and water from leaves or branches, so they often cause tree failure and shoot wilting. At the same time, the wax secreted by the ash worm will surround the host branches, hindering the photosynthetic and respiration of the host plant. In addition, its excrement is also prone to breed mold, resulting in the weakening of the growth of host plants.
Ash bug control methods
The first is to strengthen plant quarantine, strictly prohibit the transfer of insect seedlings in and out, and prevent their spread and spread.
The second is to regularly check the host plants that have been colonized. Once the ash bug hazard is found, the insect branches are manually cut down immediately to reduce the number of insect mouths. Manual pruning of insect branches should be done thoroughly and carefully, and the pruned branches should be burned in a timely and concentrated manner. At the same time, we must also pay attention to protecting and making good use of natural enemies such as black-edged red ladybirds.
The third is to make good use of the growth and development of the ash bug itself for pharmaceutical prevention and control, and we must seek the most suitable prevention and control period and take corresponding prevention and control measures.
The period between late April and May is when the female adult wax bug expands and softens, and the effect of the drug increases when the drug is applied. It can be sprayed with 40% oxidized 500 times liquid + 4.5% high-performance cypermethrin 500 times liquid + 20% thiazidone and 800 times liquid of phosphorus for mixed application prevention and control.
In addition, the nymph incubation period before the beginning and middle of June is also a key control period, at which time the agents that can be sprayed are: 10% imidacloprid 600 to 800 times liquid, or 20% waxworm 1200 times liquid, or 20% cypermethrin 2000 times, or 4.5% high efficiency cypermethrin 2000 times, or 2.5% high efficiency cypermethrin 1500 times, or 50% dichlorvos 800 to 1000 times liquid, or 1.2% nicotinine 1000 times liquid, or 25% oyster net emulsion 800 times liquid and other agents.
Due to the uneven hatching of ashworm nymphs, it is generally necessary to re-administer the drug at intervals of 5 to 7 days, usually 3 to 4 consecutive applications can effectively kill the nymphs of the ash bugs. It should be noted that when applying the drug, it is necessary to pay attention to spraying through the inner chamber, and strive to spray wet and spray thoroughly.
From late June to early to mid-July, 30% acetamolone 500 times liquid + 20% imidacloprid emulsion 500 times liquid can be sprayed. It is generally necessary to spray once every 10 days, at this time, the spray should pay attention to the front and back sides of the sprayed leaves and the branches of the host plant. In the later stage, when the ash borer secretes wax, it is necessary to use agents such as beetle killing insects, thiazidone and phosphorus killing 500 times liquid that are specially used to kill insects.