Melissodes robustior

Cockerell, 1915

robust long-horned bee

Melissodes robustior, commonly known as the long-horned , is a of long-horned bee in the . It is to the West Coast of North America. Male individuals have been observed exhibiting the characteristic sleeping of the Melissodes, clustering on flowers or stems at night while females nest underground.

Melissodes robustior by the Smithsonian. Used under a CC0 license.

Pronunciation

How to pronounce Melissodes robustior: //məˈlɪs.oʊˌdiːz roʊˈbʌs.ti.ɔr//

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

Identification

As a member of the Melissodes, males likely possess the elongated that give long-horned their . Identification to level requires expert examination; Robbin Thorp, distinguished emeritus professor of at UC Davis, identified specimens as "possibly M. robustior" based on visual characteristics in field observations.

Images

Habitat

Observed in gardens and areas with abundant flowering plants. Associated with Mexican sunflowers (Tithonia rotundifolia) and other nectar-rich blooms where males have been documented sleeping.

Distribution

West Coast of North America. Specific records include California, with observations from Vacaville in the Central Valley region.

Life Cycle

Females nest in the ground, creating burrows with distinctive round entrance holes approximately the diameter of a pencil or slightly smaller, sometimes with small of dirt resembling mini-volcanoes. Each female digs her own burrow. Males do not participate in nest construction.

Behavior

Male sleeping observed on flowers and stems, beginning around sunset and continuing until morning. Males cluster in groups on suitable perches, with some jostling for position initially. Sleeping aggregations are based on suitable perch availability rather than proximity to female nests, though typically within 100 yards of the nearest female nest. Males are territorial and will defend floral resources from other .

Ecological Role

. As a member of the tribe Eucerini, contributes to of flowering plants in its range.

Human Relevance

Subject of citizen science observation and photography. Males cannot , making them harmless to humans. Contributes to garden and serves as an educational example of .

Similar Taxa

Melissodes agilisClosely related with similar male sleeping on flowers; distinguished by subtle morphological differences requiring expert identification
Svastra obliquaRelated long-horned with similar male roosting ; may co-occur in same and requires careful examination to distinguish

More Details

Taxonomic Note

Field identification to level within Melissodes is challenging. The specific epithet "robustior" (Latin comparative of "robustus," meaning more or stronger) suggests this species may be distinguishable by relatively stouter body proportions compared to , though this requires verification.