Weevil Beetles: Overview
Weevils are a highly diverse group of beetles belonging to the superfamily Curculionoidea, with the family Curculionidae being the largest and most well-known group within this superfamily. They are commonly referred to as weevils or snout beetles due to their distinctively elongated snouts or rostrums, which house their mouthparts and are used for feeding and boring into plant material.
Book novelties:
Prioninae of the World I.
Cerambycidae of the Western Paleartic I.
Physical Characteristics
Snout (Rostrum): The most defining feature of weevils is their elongated snout, which varies in length among species and is used for feeding and laying eggs.
Body Shape: Weevils typically have compact, oval or cylindrical bodies, and most species are small, generally ranging from 1 mm to 10 mm in length, though some can be much larger.
Coloration: Their coloration is often brown or black for camouflage, but some species exhibit brighter colors.
Antennae: Weevils have elbowed (geniculate) antennae that often fit into grooves on their snouts.
Weevil Beetles
Life Cycle
Stages: Egg → Larva (grub) → Pupa → Adult.
Egg Laying: Females often lay eggs inside plant tissues, seeds, or grains, where larvae develop and feed.
Larvae: The larvae are typically legless, white or yellowish, and feed internally in seeds, stems, or roots.
Feeding Habits and Impact
Diet: Most weevils are herbivorous, feeding on a wide variety of plant materials, including leaves, stems, seeds, roots, and stored grains.
Specialization: Many species are highly specialized, feeding on specific plants or plant parts.
Economic Impact: Several weevil species are significant agricultural pests, causing damage to crops and stored food products. Notable examples include the grain weevil (Sitophilus granarius), rice weevil (S. oryzae), and boll weevil (Anthonomus grandis), which have major economic impacts worldwide.
Distinction from Other Beetles
Weevils are a family within the order Coleoptera (beetles), distinguished from other beetles primarily by their snout and elbowed antennae. While all weevils are beetles, not all beetles are weevils.
Diversity
Species Count: Over 60,000 species of weevils have been identified worldwide, making them one of the largest animal groups.
Habitat: They are found in a variety of habitats, from forests and fields to human food storage facilities, demonstrating remarkable adaptability.
Summary Table: Weevil Beetles
Feature Description
Scientific Superfamily Curculionoidea
Common Names Weevils, snout beetles
Key Physical Traits Elongated snout, elbowed antennae, compact oval/cylindrical body
Size Range 1–10 mm (most species), up to 38 mm in some
Diet Herbivorous (plants, seeds, grains, roots)
Economic Impact Major pests of crops and stored grains
Diversity Over 60,000 species worldwide
Weevils are notable for their ecological importance and their impact on agriculture, making them a subject of both scientific interest and practical concern.