Stenodynerus blandus
(de Saussure, 1870)
Stenodynerus blandus is a of in the , Eumeninae. It is a small, solitary, cavity-nesting that provisionally places paralyzed in pre-existing cavities for its larval offspring. The species is difficult to distinguish from the closely related Parancistrocerus based on external alone, often requiring microscopic examination for definitive identification. It has been documented utilizing artificial nesting structures such as blocks.
Pronunciation
How to pronounce Stenodynerus blandus: /ˌstɛnəˈdɪnərəs ˈblændəs/
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Identification
Stenodynerus blandus cannot be reliably distinguished from Parancistrocerus based on images of live specimens; microscopic examination of diagnostic characters is typically required. The Stenodynerus is characterized by specific features of the propodeum and tergite structure that separate it from related eumenine genera. Within Stenodynerus, species-level identification requires examination of male and other subtle morphological characters.
Habitat
Found in areas where suitable nesting cavities occur, including dead wood with borings, hollow twigs, and artificial structures such as blocks. Associated with open where are abundant.
Distribution
Documented from North America; specific range details not well established in available sources. Related in the occur across much of the United States and southern Canada.
Seasonality
activity period not precisely documented; related are typically active from late spring through summer.
Life Cycle
Solitary cavity-nesting . Females utilize pre-existing tunnels ( borings, hollow stems, or artificial cavities) to construct multi-celled nests. Each is provisioned with paralyzed as food for a single larval offspring. Cells are partitioned with mud or material. The consumes the provisioned , pupates within the cell, and emerges as an the following season or later.
Behavior
Females demonstrate territorial around nesting sites. Males may and defend territories near resources attractive to females. The has been observed utilizing artificial blocks, where females were seen entering cavities and being targeted by parasitic sapygid .
Ecological Role
of , contributing to of lepidopteran . Serves as for parasitic including sapygids ( ). Provides for various and .
Human Relevance
Occasionally encountered by observers artificial blocks or bee hotels. Potential incidental during nectar foraging, though this has not been documented specifically for this .
Similar Taxa
- Parancistrocerus spp.Externally nearly identical; distinguished by microscopic examination of propodeal and tergite structure
- Other Stenodynerus speciesRequire examination of male and detailed morphological characters for separation
More Details
Taxonomic Status
Stenodynerus blandus was originally described by de Saussure in 1870. Some sources list it as a heterotypic synonym of Rhynchalastor blandus, reflecting historical taxonomic instability in eumenine generic limits.
Observation Notes
Documented in a Colorado block study where females were observed entering nesting cavities and being parasitized by sapygid . The difficulty of distinguishing this from Parancistrocerus in field conditions was noted.