Pachymerus
Thunberg, 1805
Species Guides
1- Pachymerus nucleorum(Coconut Borer)
Pachymerus is a of seed beetles in the Bruchinae (formerly Bruchidae), Chrysomelidae. in this genus are specialized seed of palms (Arecaceae), with documented associations including Syagrus coronata (licuri palm), Syagrus romanzoffiana ( palm), and babassu palms (Orbinya spp.). The genus has been studied for its tritrophic interactions with , particularly Heterospilus species, and its role in palm seed in Neotropical .



Pronunciation
How to pronounce Pachymerus: //ˌpækɪˈmɛrəs//
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Habitat
Associated with palm-dominated environments including Brazilian Caatinga, Atlantic Forest remnants, and managed pastures. occur where palm fruits are present, particularly in areas with fallen fruits on the soil surface under palm .
Distribution
Neotropical region, with documented records from Brazil (including Alagoas and semi-arid Caatinga regions) and Colombia.
Diet
Specialized seed of palm seeds (Arecaceae). Larvae feed internally on seeds within the hard endocarp of palm drupes. Documented seeds include Syagrus coronata (licuri palm), Syagrus romanzoffiana ( palm), and babassu palm (Orbinya spp.).
Host Associations
- Syagrus coronata - seed licuri palm; fruits fallen on soil surface
- Syagrus romanzoffiana - seed palm
- Orbinya spp. - seed babassu palm
- Heterospilus prosopodis - Braconidae
- Heterospilus sp. - Braconidae
Life Cycle
Females lay on the surface of fallen palm fruits. Larvae develop inside the seed under the hard drupe endocarp, feeding on the seed tissue. Larval guts contain amylolytic for digesting starchy seed material. Development occurs protected within the seed, though larvae remain vulnerable to that can penetrate the endocarp.
Behavior
associated with fallen palm fruits on the ground. Abundance appears unaffected by management intensity (natural vs. managed pastures), though rates vary with habitat type.
Ecological Role
Seed in palm ; part of tritrophic involving . Serves as for braconid parasitoids. Contributes to natural dynamics and palm .
Human Relevance
Economic pest of economically important palm including oil palm and babassu. Subject to microbial association studies in agricultural contexts.
Sources and further reading
- BugGuide
- Wikipedia
- GBIF taxonomy match
- iNaturalist taxon
- NCBI Taxonomy
- Catalogue of Life
- Interação tritrófica entre Pachymerus cardo (Fahraeus), Pachymerus nucleorum (Fabricius) (Coleoptera, Chrysomelidae, Bruchinae) e seus parasitoides em populações de Syagrus romanzoffiana (Cham.) Glassman (Arecaceae)
- Pachymerus thoracicus Prevett (Coleoptera: Bruchidae), Its Host Palm and Places of Occurrence
- Natural Vs Managed Habitat: Effect Over the Seed-Predator Pachymerus nucleorum and Its Natural Enemies
- Culture- Dependent Characterization of Microbes associated with Oil Palm Kernel Borer, Pachymerus cardo in the Niger Delta
- Partial characterization of amylasic activity present in the intestine of Pachymerus nucleorum larvae (Fabricius, 1792)
- The toxicity of deltamethrin to pine beauty moth Panolis flammea schiff. and its parasitoids Barichneumon bilunulatus grav. and Rictichneumon pachymerus katz
- Record of tritrophic relationship between Syagrus coronata (Martius) Beccari (Arecaceae), Pachymerus nucleorum Fabricius (Coleoptera: Chrysomelidae: Bruchinae) and Heterospilus sp. (Hymenoptera: Braconidae) in the State of Alagoas, northeastern Brazil