Leg-spur Sand Wasp
S3, Female, ventral showing Black
Leg-spur Sand Wasp
S6, Female, ventral
Animals
Plants
Info
| Leg-spur Sand Wasp S3, Female, ventral showing Black | | Leg-spur Sand Wasp S6, Female, ventral | | ||
Animals Plants Info |
 | Class: | Animals (Animalia) - Jointed Legs (Arthropoda) - Insects (Insecta) | ||||||||||||
| Order: | Ant Bee Wasps (Hymenoptera) | |||||||||||||
| Family: | Square-headed Wasp (Wasp: Crabronidae) iNaturalist Observation | |||||||||||||
| Species: | Leg-spur Sand Wasp (Bembix flaviventris)| This Photo: | 🔍S3, Female, ventral hiding Black🔎 | Thank you Kerri-Lee Harris & David Barros Muniz (David_Bio) for identifying this species for us General Species Information: Found on Ellura (in the Murray Mallee, SA) and elsewhere 1st Live Photo on-line: ~14mm long Females, ~15mm to ~16mm long males (unusually larger). Notice the 2 ventral shots with S3. They seem very different, but the black marks are hidden when it curves it's abdomen in; they were only visible when it's fully stretched out. The sizes between the two extents were ~14mm to ~18mm, quite large variations. Kerri-Lee said to use the shorter size, saying "the more relaxed (& typical) posture. Many wasps can extend their metasoma in the way you describe. Male flower wasps are a classic example, often 'stretching' considerably when perched and preening. The size range listed for female B. flaviventris is 11-16mm ... so yours falls neatly inside this range." Kerri-Lee identified both S3 & S8, David identified the males. It's interesting to note the variations in the dorsal markings of the specimens, even though they are the same species. To help us differentiate S3 from other Bembix species Kerri-Lee kindly shared the diagnostic & location information: "Diagnostic front tibial spurs!! ... otherwise B. flavipes is very difficult to distinguish from B. mianga (and the two species occur together, so location is no clue). So, the features of particular note are:
An interesting note. The short wings of this and related species such as B. mianga produce a "lound hum which rises to a whine when they are hovering or flying very slowly, as when they approach their nests with prey" (Evans & Matthews, 1973, p. 224). Something to listen out for in the field." Of S8 Kerri-Lee said "Even though the diagnostic front tibial spur isn't visible in this series, we can exclude B. mianga (the other, similar species) as the vertex is not higher than the eye tops (it is described as 'considerably above' in B. mianga). Note that the difference in the extent of the dorsal mesosomal markings is within the normal range of variability (of this and many species)." Of the males David said "Front tibial spur broad, subcircular but with a notch on the inner margin; metasomal venter bright yellow except sometimes with a black streak on the median process of the sternite 2." Kerri-Lee's notes on features are related to each specific photo series. She has made a more complete Worksheet on her website to help separate Bembix wasps.
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