Which is the damaging stage of rice weevil?

Eggs hatch in a few days under favorable temperature and moisture conditions (28 °C and 70% relative humidity). After 35 to 40 days, the adult rice weevil chews his way out of the rice kernel, leaving behind the characteristic small, round hole, known as weevil damage.

What are the stages of weevils?

Adults often live for 7 to 8 months and some records are over 2 years. The egg, larva, and pupa stages of both weevils occur in the grain kernels and are rarely seen. Feeding is done within the grain kernel, and adults cut exit holes to emerge.

What damage does rice weevils cause?

Rice weevils are the most destructive pests of stored grain and they completely destroy the grain. Attack is evidenced by, Surface heating of grain. Dampness which may even cause germination.

What is the life cycle of a rice weevil?

Life Cycle

The eggs hatch in about 3 days. The larvae feed inside the grain kernel for an average of 18 days. The pupal stage lasts an average of 6 days (5-16 range). The new adult will remain in the seed for 3 to 4 days while it's cuticle hardens and matures.

Are weevils harmful?

Are weevils harmful? Weevils are not harmful to humans or animals, so you have nothing to worry about if you spot them inside your home. They can, however, cause extensive damage to stored cupboard foods, so always throw away any food where you find their presence.

How to Get Rid of Rice Weevils (4 Easy Steps)

What is host range and order of caster rice weevil?

Crop Protection :: Storage insects and their management. Rice weevil: Sitophilus oryzae, S. zeamais, S. granarius. Host range: Wheat, rice, maize, jowar, paddy.

Which among the different rice pest insect is the most destructive Why?

Rice stink bug

Rice stink bugs are also known as grain-sucking insects because that is how they damage rice crops. Their mouthparts penetrate the developing grain and suck the white fluid referred to as 'milk'.

What is rostrum in rice weevil?

The weevil rostrum is essentially an extension of various head sclerites that are basal to the mouthparts. Therefore, while the mouthparts are fairly similar to other Coleoptera in basic form, the head is markedly different due to its anterior extension.

How do weevils damage crops?

The bean stem weevil (Alcidodes leucogrammus), bores into the base of the stem of French bean (Phaseolus) or cowpea (Vigna) plants and lays a small number of eggs. These hatch in about 6 days to larvae. The larvae feed on the stem tissue and damage the plant, sometimes causing the stem to break off or fall over.

Which is the secondary stored grain pest?

Flour beetles are secondary pests of all grains and primary pests of flour and other milled products. In grains, embryo or germ portion is preferred. They construct tunnels as they move through flour and other granular food products.

What is the scientific name of rice weevil?

Sitophilus oryzae (lesser grain weevil or rice weevil); adults in rice grains. Copyright.

What is the nature of damage of rice black bug?

Black bugs remove the sap of the plant. They can cause browning of leaves, deadheart, and bugburn. Their damage also causes stunting in plants, reduced tiller number, and formation of whiteheads. On severe cases, black bugs weaken the plant preventing them from producing seeds.

What are the three major pest of rice?

In the early stages of the rice crop, several common insects such as the leaffolder, whorl maggot, and armyworms can cause highly visible damage symptoms; however, the damage is rarely enough to reduce yield because the crop can compensate for early damage over the rest of the growing season.

Which of the following pest causes damage to the grain at milky stage?

Symptom of Damage : Sucking the sap from individual grains, which are in milky stage. Due to de-sapping, grains show brownish discoloured patches on the husk.

What is primary and secondary pest?

Grain insect pests may be divided into primary and secondary pests. Primary grain insects have the ability to attack whole, unbroken grains, while secondary pests attack only damaged grain, dust and milled products.

Are weevils harmful to plants?

Outdoors, weevils can kill garden plants. Indoors, the pests are more of a nuisance than a danger. Weevils contaminate infested food with their feces and cast skins, causing more damage than they eat. So, an infestation may render entire packages or pantries of food inedible.

Are rice weevils harmful to birds?

They are perfectly harmless to the birds and the birds will enjoy eating them as a tasty snack. However, bird seed and other foods should be kept outdoors (see some more information on this below) to avoid the moths spreading into pantry food items such as oats, flour, rice and other grains.

Do rice weevils bite?

Rice and granary weevils are harmless to people, houses, furniture, clothing and pets. They cannot bite or sting and they do not carry diseases. They will not feed on furniture, the house structure or other items. The harm they do is destruction of the seeds they infest and the annoyance of being in the wrong place.

Which stage of pulse beetle is damaging?

Pulse beetles are serious pests of stored pulses like pigeon pea, green gram, black gram, cowpea and chickpea. The white coloured eggs hatch after 4 to 5 days. The grub makes a hole inside the grain which causes heavy damage. This reduces the quality as well as market prices.

Which is primary store grain pest?

Primary pests

Primary grain pests attack the whole grain. The eggs are laid inside the grain, before the larvae mature inside the grain and then chew their way out. Some of these pests include the Lesser grain borer, Granary weevil (Sitophilus granarius, the Wheat weevil) and Rice weevil (Sitophilus oryzae).

What are the indirect damages caused by the grain beetle?

Insects and other animals also cause indirect damage, which results in the contamination and deterioration of the grain. This in turn, leads to reduced quality and lower market value, which can be attributed to the presence of heat damage, intact dead insects, insect parts, odors, or molds.