How to prevent and control the latest rice water weevil?

Rice water weevil is one of the most harmful alien invasive species in China, but it has not been included in the list of the first batch of alien invasive species in China. It is also known as rice water weevil and rice root weevil. It is a class II quarantine pest native to North America. It was first discovered in Tanghai County, Tangshan City, China in 1988, and now it has occurred in 11 provinces and cities across the country. Let's take a look at how rice water weevil can be prevented and controlled.

Morphological characteristics of rice water weevil

The adult rice water weevil is 2.6 to 3.8 mm long, and its beak is as long as the forechest dorsal plate, slightly curved, flat cylindrical. The anterior chest and dorsal plate is wide. The lateral margin of the sheath wing is parallel, wider than the anterior thoracic dorsal plate, the shoulder is oblique, and there is a tumor process on the half of the end of the sheath wing. The posterior tibial segment of the female has anterior sharp process and sharp process, and the sharp process is long and sharp, while the male has only short, thick, bifurcate sharp processes. Pupa ca. 3 mm, white. The larvae are white with a yellowish brown head. Ovoid cylindrical, round at both ends.

Damage characteristics of rice water weevil

Rice water weevil is a semi-aquatic insect, adults overwinter on ground withered grass, mate and lay eggs in late March, and most of the eggs are laid in the flooded leaf sheath. The newly hatched larvae only feed in the leaf sheath and then enter the root to feed. Eclosion adults climb out of the pupa chamber attached to the root and feed on the leaves of rice or weeds. The average life span of adults is 76 days, and that of females is even longer, up to 156 days. When endangered, the population density can reach more than 200 per square meter.

Control methods of rice water weevil

Mu with 4.5% cypermethrin EC 3000 times spray, 48% chlorpyrifos EC 1000 times liquid spray, mu with 48% chlorpyrifos 150ml mixed poisonous soil 15kg sprinkling, field water conservation, make it naturally dry. When spraying, add rice high yield king or other foliar fertilizer and mediator to supplement nutrition and reduce loss. In the high temperature season, we should pay attention to the safe use of medicine, do a good job in the personal protection of drug application personnel, and spray after 5 o'clock in the afternoon.

Control method of rice water weevil

1. The survival rate of overwintering adults in rice field can be greatly reduced by autumn tillage. Combined with fertilizer accumulation and field management, weeds can be removed to eliminate overwintering adults.

2. Ploughing the land in time after rice harvest can reduce its overwintering survival rate and protect natural enemies such as frogs, toads, spiders, ants, fish and so on.

3. Beauveria bassiana and nematodes are effective in the control of adults, and pyrethroid pesticides are suitable for application.

4. It is strictly forbidden to transfer articles from the epidemic area that can carry and spread the pest. Vehicles and packing materials from the epidemic area should be strictly inspected, and pest control should be done if necessary.