Sitophilus oryzae (Insect identification)

 Specimen 2

IDENTIFYING FEATURES

• Head has conspicuous compound eyes.
• Antennae usually with less than 11 segments & biting mouthparts.
• Ocelli aare typically absent.
• Prothorax is large & freely articulated with the rest of thorax.
• Toughened front wings or elytra, meet the body midline & cover the larger membranous hindwings, which are folded lengthwise & crosswise underneath.

                                          - Hence the specimen belongs to the Order: Coleoptera

• Adult is about 2.5-4mm in length & reddish brown in colour.
• Head bears a slender, forwardly pointed projection.
• Presence of a pair of stout mandibular jaws.
• Elytra have two reddish/yellowish spots.
• Club Shaped Antennae are 9-segmented.

                                         -Hence the specimen seems to be Sitophilus oryzae

Systematic position (Ruppert & Barnes, 1994)

Kingdom: Animalia

      Phylum: Arthropoda

             Class: Insecta

                   Sub Class: Pterygota

                         Order: Coleoptera

                               Superfamily: Curculionoidae

                                           Family: Curculionidae

                                                        Genus: Sitophilus

Economic importance:

• Sitophilus oryzae (rice weevil) is a major pest of stored grains worldwide, including rice, wheat, maize, barley, and other cereals.

• Infestation leads to significant quantitative and qualitative losses, with post-harvest loss ranging from 5–30% of stored grains depending on severity and conditions.​

• Economic impacts include reduced market value and rejection from export markets due to deteriorated grain quality.​

• The pest damages grain by hollowing out kernels, which decreases weight, nutritional content (up to 20–30% loss), and leads to powdery residues or spoilage.​

• Notable symptoms are exit holes in grains, powdery debris, and heating of stored grain, complicating early detection and management.​

• Infestation increases storage costs through higher pest control, fumigation, and the need for improved storage techniques.​

• Persistent infestations pose a threat to food security and economic stability in grain-producing and storing regions.​

• Sustainable pest management, including integrated pest management (IPM), chemical, biological, and physical controls, is vital to minimize losses and reliance on chemical pesticides.