How to get rid of maize weevils? A few simple methods to teach you

Abstract Agricultural control: In late autumn and early winter, spread gunny sacks on the grain surface or around the grain pile to lure adult weevils to hide under the sacks, then collect and kill them; when it turns warm in spring, spray a pesticide belt around the outside of the warehouse to block adult weevils that overwintered outside from re-entering the warehouse. Chemical control: use chemicals such as methyl bromide or aluminum phosphide for sealed warehouse fumigation. Biological control: insert a straw bundle or bamboo tube on top of the grain pile; when you stir the grain by hand, the adults will crawl onto the straw bundle or into the bamboo tube on top of the pile to hide, then collect and kill them.

I. Simple methods to get rid of maize weevils

1. Agricultural control

In late autumn and early winter, when large numbers of adult weevils crawl out of the grain pile to overwinter, spread gunny sacks on the grain surface or around the grain pile to lure the adults to hide under the sacks, then collect and kill them; when it turns warm in spring, spray a pesticide belt around the outside of the warehouse to block adult weevils that overwintered outside from re-entering the warehouse. During this period, the grain also needs to be sun-dried and sieved.

2. Chemical control

Malathion can be mixed into the grain pile at a weight ratio of 1/10000. When maize weevils occur rather seriously in the grain warehouse and ordinary methods are unsuitable, chemicals such as methyl bromide or aluminum phosphide can be used for sealed warehouse fumigation.

3. Biological control

Generally, advantage can be taken of the adults' habit of crawling upward: make many small pointed mounds on the grain surface, insert 1 straw bundle or bamboo tube on top of each mound, and when you stir the grain by hand, the adults will begin to crawl onto the straw bundle or into the bamboo tube on top of the mound to hide, and during this time they can be collected and killed.

II. Living habits of the maize weevil

1. The maize weevil mainly infests maize, buckwheat, beans, peanut kernels, hemp seeds, grain flour, dried fruit, yeast cakes, macaroni and bread, among others.

2. The larvae only bore into and feed on cereal seeds, among which maize, wheat and sorghum suffer the heaviest damage. It produces 1 generation to several generations per year, varying by region. It can not only reproduce inside the warehouse but also fly to the field to reproduce. It has relatively strong cold resistance, starvation resistance and egg-laying capacity, and its development speed is also relatively fast.

III. Morphological characteristics of the maize weevil

1. Maize weevil egg: oval, 0.65-0.70 mm long and 0.28-0.29 mm wide, milky white, semi-transparent, slightly rounder and larger at the lower end and gradually narrower toward the upper end, with a cap-shaped round small protuberance at the upper end; the egg of the granary weevil is similar to it.

2. Maize weevil larva: body length 2.5-3.0 mm, milky white, body mostly transversely wrinkled, back arched, ventral surface flat, whole body plump, thick and short, slightly hemispherical, legless, head small, light brown, slightly wedge-shaped; the larva of the granary weevil is similar to it.

3. Maize weevil pupa: body length 3.5-4.0 mm, oval, milky white to brown, head round, snout-like part extending to the middle leg coxae, with 8 pairs of small protuberances on the pronotum, each bearing 1 brown bristle, abdomen with 10 segments, and a pair of fleshy spines at the end of the abdomen.

IV. Damage caused by the maize weevil

1. The maize weevil is the number one pest of stored grain in our country and is also an important stored-grain pest worldwide. The maize weevil is a boring pest; the adults like to feed on cereal seeds as well as stored goods such as flour, oil materials and plant-based medicinal materials, and generally wheat, maize, brown rice and sorghum suffer heavier damage.

2. The larvae cause damage only inside cereal seeds, mainly damaging old grain stored for 2-3 years. The adults gnaw and the larvae bore into the grain kernels. It is a major primary pest. When stored grain is bitten and eaten by maize weevils, large amounts of broken grains and powder fragments result, which easily leads to the occurrence of secondary pests. After damage, it can increase the moisture content of the grain and cause it to heat up, and it can also fly to the field to cause damage.