Pseudoanthidium tenellum

Taxonomy

Family: Megachilidae
Subfamily: Megachilinae
Tribe: Anthidiini
Genus: Pseudoanthidium, Friese 1898
Subgenus: Pseudoanthidium, Friese 1898
Species: Pseudoanthidium tenellum (Mocsáry, 1880)

Background

Pseudoanthidium tenellum are relatively small, 6–9 mm bees. They have a predominantly black integumentintegument:
a tough, protective outer layer
with symmetrical yellow markings on their face, tergaterga:
the segments on the top side of the abdomen, often abbreviated when referring to a specific segment to T1, T2, T3, T4, T5, T6, or T7
, and often the scutellumscutellum:
shield shaped plate behind scutum
. Their legs are yellow to orange and may be black at the base. The size of the yellow portions varies within the species. Males tend to have yellow mandibles and a larger yellow portion of their face. Females tend to have black mandibles and smaller yellow portions of their face. Both male and female specimens have a thin coat of white pubescencepubescence:
short, fine hair
that covers most of their bodies. Their wings are translucent and sometimes slightly brown.

Distribution

Pseudoanthidium tenellum are known from Southern Europe through Central Asia (Litman et al. 2021Litman et al. 2021:
Litman, J. R., Fateryga, A. V., Griswold, T. L., Aubert, M., Proshchalykin, M. Y., Le Divelec, R., Burrows, S. & Praz, C. J. 2022. Paraphyly and low levels of genetic divergence in morphologically distinct taxa: revision of the Pseudoanthidium scapulare complex of carder bees (Apoidea: Megachilidae: Anthidiini). Zoological Journal of the Linnean Society, 195(4): 1287-1337.)

Host associations

Pseudoanthidium tenellum floral associations are limited, but they have been observed visiting Centaurea scabiosa, and Pulicaria salviifolia (Asteraceae), and Limonium scoparium (Plumbaginaceae).

Diagnostic characteristics

(Modified from Litman et al. 2021Litman et al. 2021:
Litman, J. R., Fateryga, A. V., Griswold, T. L., Aubert, M., Proshchalykin, M. Y., Le Divelec, R., Burrows, S. & Praz, C. J. 2022. Paraphyly and low levels of genetic divergence in morphologically distinct taxa: revision of the Pseudoanthidium scapulare complex of carder bees (Apoidea: Megachilidae: Anthidiini). Zoological Journal of the Linnean Society, 195(4): 1287-1337.)

• Female T1–T2 punctationpunctation:
  overall pattern of the punctures on a surface of a bee, includes size of punctures and the distance between them
  coarse with shiny interspaces, and smaller in diameter than the largest punctures on the scutellumscutellum:
  shield shaped plate behind scutum
  .

• Male gonostylusgonostylus:
  the apical-most appendage of the male genitalia, which is usually quite hairy
  approximately 1.5x wider at widest point than at the base. Notch at the apexapex:
  end of any structure
  less deep than wide.

• Male S3S3:
  the plates on the underside of the abdomen, often abbreviated when referring to a specific segment to S1, S2, S3, S4, S5, S6, S7, or S8
  premarginal brush with unhooked hairs at the tips.

• Male S3S3:
  the plates on the underside of the abdomen, often abbreviated when referring to a specific segment to S1, S2, S3, S4, S5, S6, S7, or S8
  with trapezoidal, shiny to matte, hairless zone that doesn’t extend along the midline.

• Male laterallateral:
  relating, pertaining, or attached to the side
  combs on S5S5:
  the plates on the underside of the abdomen, often abbreviated when referring to a specific segment to S1, S2, S3, S4, S5, S6, S7, or S8
  mitten-shaped. 

• Male third trochantertrochanter:
  segment of the insect leg between the coxa and the femur
  hairs shaggy and uneven.

May be confused with

Pseudoanthidium tenellum is most similar to P. rozeni. Males can be distinguished by the mitten shaped laterallateral:
relating, pertaining, or attached to the side
combs on S5S5:
the plates on the underside of the abdomen, often abbreviated when referring to a specific segment to S1, S2, S3, S4, S5, S6, S7, or S8
and the gonostylusgonostylus:
the apical-most appendage of the male genitalia, which is usually quite hairy
with V-shaped emarginationemargination:
a notched or cut out place in an edge or margin, can be dramatic or simply a subtle inward departure from the general curve or line of the margin or structure being described
that is wider than deep. Females can be distinguished by the punctures on the tergaterga:
the segments on the top side of the abdomen, often abbreviated when referring to a specific segment to T1, T2, T3, T4, T5, T6, or T7
, which are smaller than the largest punctures on the scutellumscutellum:
shield shaped plate behind scutum
.

Nesting behavior

Little is known about the nesting biology of Pseudoanthidium tenellum but most species of Pseudoanthidium nest in pre-existing cavities like in wood, stems, galls or crevices (Litman et al. 2021Litman et al. 2021:
Litman, J. R., Fateryga, A. V., Griswold, T. L., Aubert, M., Proshchalykin, M. Y., Le Divelec, R., Burrows, S. & Praz, C. J. 2022. Paraphyly and low levels of genetic divergence in morphologically distinct taxa: revision of the Pseudoanthidium scapulare complex of carder bees (Apoidea: Megachilidae: Anthidiini). Zoological Journal of the Linnean Society, 195(4): 1287-1337.).

Known invasives

There are no known invasives.