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Beetles of Zihuatanejo

ORDER COLEOPTERA

Pachymerini Pea and Bean Weevils
Pachymerini (Tribe)

-Animals (Kingdom Animalia)

-Arthropods (Phylum Arthropoda)

-Hexapods (Subphylum Hexapoda)

-Insects (Class Insecta)

-Winged and Once-winged Insects (Subclass Pterygota)

-Beetles (Order Coleoptera​​)

-​Water, Rove, Scarab, Long-horned, Leaf, and Snout Beetles (Suborder Polyphaga)

-​Cucujiform Beetles (Infraorder Cucujiformia)

-Leaf Beetles and Allies (Superfamily Chrysomeloidea)

-Leaf Beetles Family (Chrysomelidae)

-Pea and Bean Weevils (Subfamily Bruchinae)

-Tribe Pachymerini


Pachymerini, commonly referred to as Pea and Bean Weevils, are a tribe within the family Chrysomelidae, subfamily Bruchinae (Seed Beetles). These beetles are known for their close association with legumes, particularly peas and beans, where they act as both natural seed predators and, in some cases, agricultural pests.

Diet

  • Adults: Adults generally feed little and may consume pollen, nectar or plant material, although some species take little or no food after emergence.

  • Larvae: Develop inside seeds of legumes (Fabaceae), where they consume the nutritious seed contents.

  • Many species are closely associated with large legume seeds, including those produced by trees, shrubs and climbing plants.

Range

  • Pachymerini is a predominantly tropical and subtropical tribe of seed beetles, occurring throughout the Americas, Africa and other warm regions.

  • Around Zihuatanejo, Pachymerini are occasional, but individual species can become locally common when their host plants are producing mature seeds.

  • Look especially around legume-bearing trees, shrubs and vines, where adults may be found on foliage or where infested seeds accumulate.

Habitat

  • Found in tropical dry forest, tropical deciduous forest, woodland, scrub, forest edges, agricultural areas and gardens.

  • Adults may be encountered on leguminous plants or nearby vegetation.

  • The most productive place to find evidence of Pachymerini is often inside mature or fallen legume seeds, where larvae and pupae develop.

  • Seeds may show a characteristic circular emergence hole after the adult beetle has completed development and chewed its way out.

Size

  • Adult length: approximately 4–20 mm (0.16–0.8 in), depending on species.

  • Body generally compact, robust and oval, with short wing covers and relatively stout hind legs.

  • Colouration is commonly brown, reddish-brown, black or mottled, providing camouflage among seeds and dried vegetation.


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