Rice reevil

About Rice weevil

1. Rice Weevil Nawang Sherpa

2. Sitophilus oryzae major pest in stored grain products like rice, maize ( मकै ), sorghum( ज्वारी ), corn, barley( जौ ) and wheat ( गहुँ ) grow in humid conditions with moderately high temperature larval and adult stages of rice weevils damage the stored grain products. Thus, knowledge on its morphology, life cycle is required to know about infested products and possible control measures is vital in overcoming the damage caused by rice weevil. INTRODUCTION

3. Systematic Position Kingdom: Animalia Phylum Arthropoda Subphylum: Mandibulata Class: Insecta Subclass: Endopterygota Order: Coleoptera Family: Curculionidae Genus: Sitophilus Species: oryzae

4. Habit and Habitat  Rice weevil originated from India and most tropical parts of the world. one of the most destructive primary pests of stored cereals. Female use strong mandibles to chew a hole into a grain kernel after which she deposits a single egg within the hole, sealing it with secretions from her ovipositor. gather on the corner of home, cracks and gaps that lead inside. They are attracted to light and can fly

5. Morphology Size is around 3 mm The color ranges from reddish brown, chocolate to almost black The snout is long almost one-third of its total length  The larvae are soft, white grubs with no legs. Pupae are  similar  to adults with long snouts, but they are white.

6. Morphology Body divided into Head (6 segments) – Chewing type of mouthpart Thorax (3 segments) Prothorax is strongly pitted and elytra have rows of pits within longitudinal grooves Abdomen( 11 segments)

7. Nature of Damage  Rice weevils are not known to transmit any diseases to humans. However, They are dangeroud to the grain industry and can cause a lot of problems for homeowners by contaminating food sources. Enter homes through products purchased at the store that are already infested with adult rice weevils or their larvae. mainly caused by two stages of this insect (1) Larvae (2) Adult

8. Nature of Damage Adults feed on whole seeds or flour. Larvae develop in seeds or pieces of seeds or cereal products large enough to house larvae, but will not develop in flour unless it has been compacted. Indicators of a rice weevil infestation are; -Increased moisture levels and heating on the surface -Seeds with round holes formed by exiting adults

9. Nature of Damage 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 Presence of numerous adults

10. Control of Rice Weevil The fastest, safest, and most effective way to eliminate rice weevils or any other stored product pest from your home is to get help as quickly as possible from a professional. Cultural Practices dispose of heavily infested foods in wrapped, heavy plastic bags or in sealed containers for garbage removal, or bury deep in the soil. Be sure to store only clean, dry grain with a moisture content of 12 percent or less to reduce weevil problems.

11. Temperature control Temperature control can also be used to control the rice weevil. Freezing infected food below -17.7°C (0°F) for three days retards the growth and development of various stages of the insect life cycle. Heating to 60°C (140°F) for 15 minutes destroys all development stages of rice weevil. Chemical Control Application of Insecticides such as Novacide . Vinegar is effective against  rice weevils . \

12. Fumigation (  methyl bromide  and  phosphine as gaseous pesticides) Adding Dry Ice

13. Life Cycle of Rice Weevil Consists of Four Stages Egg Larva Adult Females start laying eggs 5 days after emergence Females drill a tiny hole in the grain kernel, deposit an egg in the cavity, then plug the hole with a gelatinous secretion.

14. Life Cycle of Rice Weevil Egg 4 eggs per day Total of 250-400 eggs minute, white, translucent 0.7x0.3 mm in size Legless

15. Pupa eggs after completion of incubation period of 5-8 days hatches into young larva White, black hard head Movable segments larva shows four instars

16. Boll Weevil