Sennius

Bridwell, 1946

seed beetles, pea and bean weevils

Species Guides

Sennius abbreviatus(Short-spotted Sennius)
Sennius cruentatus
Sennius discolor
Sennius guttifer
Sennius lebasi(pea weevil)
Sennius leucostauros
Sennius medialis
Sennius morosus

Sennius is a New World of seed beetles ( Bruchinae) within Chrysomelidae, containing at least 20 described . Species are organized into multiple species groups, with the S. abbreviatus group being the largest and most thoroughly studied, comprising 14 species. The genus is characterized by distinctive male genitalia , particularly patterns of and internal sac structure. Several species have been described from Mexico, Central America, and South America, with ongoing taxonomic revisions revealing new species and clarifying plant relationships.

Sennius cruentatus by (c) Thomas Koffel, some rights reserved (CC BY), uploaded by Thomas Koffel. Used under a CC-BY license.

Pronunciation

How to pronounce Sennius: /ˈsɛn.ni.us/

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Identification

Identification to level requires examination of male genitalia, specifically the pattern of and shape of the internal sac. The S. abbreviatus group is distinguished from other Sennius groups by these genitalic characters. External alone is generally insufficient for reliable species identification within the .

Images

Distribution

New World distribution, with records from North America (United States, Mexico), Central America, and South America (including Brazil, Colombia, and Ecuador). The is not native to the Old World.

Diet

Larvae feed internally within seeds of leguminous plants (Fabaceae). Specific plant associations have been documented for several , though many remain unrecorded.

Host Associations

Fabaceae - larval food sourceseed feeding; specific vary by

Behavior

females oviposit on or near developing legume pods. Larvae burrow into seeds where they complete development, consuming the seed contents. This concealed feeding habit makes larvae difficult to detect without destructive sampling of seeds.

Ecological Role

As seed , Sennius influence plant recruitment and seed bank dynamics in legume . They function as herbivores within Fabaceae-dominated .

Human Relevance

Some have potential economic significance as pests of cultivated legumes, though specific pest status varies by species and region. The is primarily of concern in agricultural contexts where wild legume serve as for of crop species.

Similar Taxa

AcanthoscelidesBoth are New World Bruchinae with seed-feeding larvae; distinguished by male genitalia and specific patterns in Sennius
BruchusOld World bruchine with similar ; Sennius is restricted to the New World and differs in genitalic and external morphological characters

More Details

Taxonomic History

Originally described by Bridwell in 1946. The has undergone significant revision, with groups defined primarily on male genitalia characters. The S. abbreviatus group was formally reviewed in 2013, resulting in description of two new species (S. vivi and S. flinte) and clarification of subgroup structure based on internal sac .

Research Needs

plant associations remain incompletely documented for most . Distribution records are actively being expanded through recent fieldwork, particularly in Brazil and Central America.