Explanation of Names
Mesostenus Gravenhorst, 1829
Numbers
1. Mesostenus albinotatus promptus: NB to BC to NC, SD, CO, & CA
2. Mesostenus americanus: QC to VA to SD
3. Mesostenus angustus : RI to NC to e. KS
4. Mesostenus clitellatus : NS to BC to VA & TX
5. Mesostenus eisenii : MD to GA to OH and TX
6. Mesostenus gracilis: NS to GA to BC and CA
7. Mesostenus liogoster : western (Cadana: BC, NT, SK, United States: CA, ID, OR, WY)
8. Mesostenus longicaudis : NY, MN, NE, & n CA south to SC, TX, & s. CA
9. Mesostenus melanurus: AB
10. Mesostenus sicarius: Canada: s. AB; United States: AZ, CA, CO, MT, NC, TX
11. Mesostenus thoracicus: QC, to BC to FL, TX, and CA
Identification
Mesostenus is noted for its slender body, unarmed frons, short and strongly convex clypeus, mostly smooth and strongly convex mesostutum, wings with a small quadrangular areolet and lacking a ramellus, long and slender first abdominal segment, and often moderately long and slender ovipositor.
(2)
A few species species are very similar in coloration. They have a black-and-white head, pronotum, mesoscutum, scutellum, and postscutellum contrasted with the rest of the body being reddish. They can be separated as follows:
(3)
M. clitellatus has the apex of the scutellum and the postscutellum black, and the propodeum has a black basal mark (like a pair of saddles).
M. eisenii has a blacker face and a fulvous to ivory postscutellum.
M. gracilis generally has the postscutellum black and the hind tarsi close to the color of the color of the tibia. Males have entirely black antennae.
(3)
M. sicarius are more fulvoferruginous than fulvous, have additional white spots on the side of the thorax, and have the fore and mid coxae marked with prominent white spots.
M. thoracicus generally has the postscutellum white and the hind tarsi paler than the color of the tibia. Males have a white band on the antennae and white hind tarsi.
(3)