Pests and control methods of two-line arrowroot

Pests of two-line arrowroot: scale insects

symptom

Scale insects are mealybugs with strong reproductive capacity and can reproduce multiple generations every year. May is the peak breeding period. The disease often occurs on the edges or backs of leaves, but it can also occur on the surface of leaves.

Scale insects use their mouthparts to pierce the leaves and suck the juice of the two-lined arrowroot. In mild cases, the leaves will turn yellow and become old, affecting the growth of the plant. In severe cases, the leaves will gradually wither and fall off until the entire plant dies.

The wounds bitten by scale insects are also easily infected by pathogens.

Adult scale insects have a waxy outer shell, so pesticides cannot completely control the pests, making them difficult to control.

Prevention and treatment methods

Pesticides should be sprayed during the peak nymph stage. At this time, the nymphs have just hatched and the wax on their body surface has not yet formed. It is easier to kill scale insects with pesticides at this time.

Use 1000 times diluted 40% oxydemeton-methyl, 1000 times diluted 50% DDT, 3000 times diluted 2.5% cypermethrin for spraying for prevention and control, spray once every 7-10 days, and spray 2-3 times continuously.

Pests of two-line arrowroot: Red spider mites

symptom

Red spider mites are relatively small and not easy to be found. They are reddish brown or orange in color. Once found, the damage they have caused is often already quite serious.

Red spider mites use their mouthparts to absorb nutrients from leaves, causing an imbalance in the plant's water metabolism and affecting its normal growth and development.

Red spider mites generally reproduce in an environment with higher temperature and lower humidity, and a single spider will do little harm to plants.

Prevention and treatment methods

Place the plants in a ventilated place, keep the humidity of the environment stable at above 40%, and spray water on the leaves frequently.

Pesticides cannot completely kill insect eggs, so adults and nymphs must be controlled after the eggs hatch. You can use 1000 times diluted 20% trichlorodicofol emulsifiable concentrate or 1000 times diluted 40% oxydemeton-methyl emulsifiable concentrate for spraying.