Anthidium maculosum

Taxonomy

Family: Megachilidae
Subfamily: Megachilinae
Tribe: Anthidiini
Genus: Anthidium Fabricius, 1804
Subgenus: A. (Anthidium) Fabricius, 1804
Species: Anthidium maculosum Cresson, 1878
Common name: none

Overview

Anthidium (Anthidium) maculosum are dark brown to black with yellow maculations (Gonzalez and Griswold 2013Gonzalez and Griswold 2013:
Gonzalez, V.H. and T.L. Griswold. 2013. Wool carder bees of the genus Anthidium in the Western Hemisphere (Hymenoptera: Megachilidae): diversity, host plant associations, phylogeny, and biogeography. Zoological Journal 168: 221ndash;425.). Females have white pubescencepubescence:
short, fine hair
except for brown hairs on the clypeusclypeus:
a section of the face below the antennae, demarcated by the epistomal sutures
, supraclypeal areasupraclypeal area:
the region of the head between the antennal sockets and clypeus, demarcated on the sides by the subantennal sutures
, fronsfrons:
the area between the antennae and ocelli on the bee's head
, vertexvertex:
the area between the ocelli and the back of the head
, inner basitarsibasitarsi:
the segment of the tarsus that is the nearest to the body of the bee, usually the largest of all the tarsal segments
, depressed marginal zones of T1–T4, T5–T6, and apexapex:
end of any structure
of S6S6:
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
. Females have a body length of 8.5–11.5 mm, and males range in body length from 9.2–13.1 mm (Gonzalez and Griswold 2013Gonzalez and Griswold 2013:
Gonzalez, V.H. and T.L. Griswold. 2013. Wool carder bees of the genus Anthidium in the Western Hemisphere (Hymenoptera: Megachilidae): diversity, host plant associations, phylogeny, and biogeography. Zoological Journal 168: 221ndash;425.).

Diagnostic characteristics

(modified from Gonzalez and Griswold 2013Gonzalez and Griswold 2013:
Gonzalez, V.H. and T.L. Griswold. 2013. Wool carder bees of the genus Anthidium in the Western Hemisphere (Hymenoptera: Megachilidae): diversity, host plant associations, phylogeny, and biogeography. Zoological Journal 168: 221ndash;425.)

• Female labrumlabrum:
  part of the head abutting the clypeus, folds down in front of the mouthparts
  lacks basalbasal:
  originating at the foundation of a structure
  protuberances and preapicalpreapical:
  referring to a section of a bee that is physically found just before the outermost (or apical) end of the section or segment
  projections.
• Female mandiblemandible:
  bee teeth, so to speak, usually crossed and folded in front of the mouth
  usually has seven teeth, but sometimes with 6–8 teeth.
• Female propodealpropodeal:
  the last segment of the thorax
  triangle is dull and finely lineolatelineolate:
  marked with fine lines
  .
• Female supraclypeal areasupraclypeal area:
  the region of the head between the antennal sockets and clypeus, demarcated on the sides by the subantennal sutures
  and fronsfrons:
  the area between the antennae and ocelli on the bee's head
  have dull integumentintegument:
  a tough, protective outer layer
  between coarse, sparse punctures.
• Female hind tibiatibia:
  the segment of the leg, between the femur and the tarsus
  with anterioranterior:
  toward the head or on the head side of a segment being described
  carina present.
• Female T1–T5 discal areas are slightly elevated, and weakly imbricateimbricate:
  overlapping, like shingles or roof tiles
  between punctures.
• Female T1–T5 depressed marginal zones have small punctures.
• Female T1–T5 distaldistal:
  place on a segment that is furthest from the place of attachment with the body
  margins are dull, thin, and almost lamellatelamellate:
  thin, plate-like, often somewhat translucent structure
  .
• Female T6T6:
  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
  preapicalpreapical:
  referring to a section of a bee that is physically found just before the outermost (or apical) end of the section or segment
  carinacarina:
  a clearly defined ridge or keel, not necessarily high or acute; usually appears on bees as simply a raised line
  is crenulatecrenulate:
  having a finely scalloped or notched outline or edge
  with a small, acute laterallateral:
  relating, pertaining, or attached to the side
  projection.
• Male mandiblemandible:
  bee teeth, so to speak, usually crossed and folded in front of the mouth
  has three teeth.
• Male supraclypeal areasupraclypeal area:
  the region of the head between the antennal sockets and clypeus, demarcated on the sides by the subantennal sutures
  and fronsfrons:
  the area between the antennae and ocelli on the bee's head
  have finer, denser punctures than those of females.
• Male S4S4:
  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
  lacks an apicalapical:
  near or at the apex or end of any structure
  brush and has a straight apicalapical:
  near or at the apex or end of any structure
  margin.
• Male S6S6:
  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
  apicalapical:
  near or at the apex or end of any structure
  margin is broadly rounded medially with a small, blunt laterallateral:
  relating, pertaining, or attached to the side
  projection that is bent ventrally.
• Male S7S7:
  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
  is slightly obliquely truncatetruncate:
  ending abruptly, or squared off
  apically; this can appear subtriangular.
• Male S8S8:
  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
  apicalapical:
  near or at the apex or end of any structure
  process is short and truncatetruncate:
  ending abruptly, or squared off
  apicallyapically:
  near or at the apex or end of any structure
  .
• Male T6T6:
  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
  laterallateral:
  relating, pertaining, or attached to the side
  spine is curved, longer, and stouter than the T7T7:
  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
  median spine.
• Male T7T7:
  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
  laterallateral:
  relating, pertaining, or attached to the side
  lobe is long and digitiform.

May be confused with

Anthidium maculosum may be distinguished from all other North American Anthidium, aside from A. chamelense, A. rodriguezi, and A. parkeri, by the combination of hind tibial carinacarina:
a clearly defined ridge or keel, not necessarily high or acute; usually appears on bees as simply a raised line
and dull fronsfrons:
the area between the antennae and ocelli on the bee's head
with coarse and sparse punctures. Anthidium maculosum can be differentiated from A. chamelense and A. rodriguezi by the presence of maculations on 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 smaller body size (Gonzalez and Griswold 2013Gonzalez and Griswold 2013:
Gonzalez, V.H. and T.L. Griswold. 2013. Wool carder bees of the genus Anthidium in the Western Hemisphere (Hymenoptera: Megachilidae): diversity, host plant associations, phylogeny, and biogeography. Zoological Journal 168: 221ndash;425.). Female A. maculosum can be differentiated from A. parkeri by the presence of denser tomentumtomentum:
a form of pubescence composed of short matted, woolly hair
on the outer surface of the basitarsibasitarsi:
the segment of the tarsus that is the nearest to the body of the bee, usually the largest of all the tarsal segments
, as well as T6T6:
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
with a weakly depressed area above the preapicalpreapical:
referring to a section of a bee that is physically found just before the outermost (or apical) end of the section or segment
carinacarina:
a clearly defined ridge or keel, not necessarily high or acute; usually appears on bees as simply a raised line
and distinct laterallateral:
relating, pertaining, or attached to the side
projections. Male A. maculosum can be differentiated from A. parkeri by the digitiform laterallateral:
relating, pertaining, or attached to the side
lobe on T7T7:
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
, shape of S6S6:
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 S8S8:
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 lack of light maculations on the scapescape:
the basal, and usually the longest, segment of the antennae
(Gonzalez and Griswold 2013Gonzalez and Griswold 2013:
Gonzalez, V.H. and T.L. Griswold. 2013. Wool carder bees of the genus Anthidium in the Western Hemisphere (Hymenoptera: Megachilidae): diversity, host plant associations, phylogeny, and biogeography. Zoological Journal 168: 221ndash;425.).

Phenology

Anthidium maculosum adults have been recorded in flight from mid-February to November, with peak activity occurring from June to September (Gonzalez and Griswold 2013Gonzalez and Griswold 2013:
Gonzalez, V.H. and T.L. Griswold. 2013. Wool carder bees of the genus Anthidium in the Western Hemisphere (Hymenoptera: Megachilidae): diversity, host plant associations, phylogeny, and biogeography. Zoological Journal 168: 221ndash;425.).

Host associations

Anthidium maculosum is a generalist that has been observed visiting a variety of species within Agavaceae, Asteraceae, Boraginaceae, Convolvulaceae, Ericaceae, Fabaceae, Iridaceae, Lamiaceae, Malvaceae, Orobanchaceae, Plantaginaceae, Polemoniaceae, Rosaceae, and Verbenaceae (Gonzalez and Griswold 2013Gonzalez and Griswold 2013:
Gonzalez, V.H. and T.L. Griswold. 2013. Wool carder bees of the genus Anthidium in the Western Hemisphere (Hymenoptera: Megachilidae): diversity, host plant associations, phylogeny, and biogeography. Zoological Journal 168: 221ndash;425.).

Nesting behavior

Anthidium maculosum nesting behavior was described based on nest trap observations (Krombein 1967Krombein 1967:
Krombein, K.V. 1967. Trap nesting wasp and bees: life histories, nests, and associates. Washington, DC: Smithsonian Press.). Based on these observations, it is presumed that A. maculosum nests in preexisting cavities. Nest plugs were comprised of only trichomes, or a combination of trichomes, pebbles, small pieces of wood, masticated plant materials, or pellets of lizard dung. Males have been observed displaying territorial behaviors, such as guarding the host plants that are preferred by the females (Alcock et al. 1977Alcock et al. 1977:
Alcock J., G.C. Eickwort, and K.R. Eickwort. 1977. The reproductive behavior of Anthidium maculosum (Hymenoptera: Megachilidae) and the evolutionary significance of multiple copulations by females. Behavioral Ecology and Sociobiology 2: 385ndash;396.).

Distribution

Anthidium maculosum occur from Honduras to the western U.S. Within the U.S., they are found in Texas, Arizona, Utah, Colorado, and California to western Oregon. In the U.S., they are present in hot deserts; the Great Basin and Colorado plateau; Mediterranean California grassland, chaparral, and woodlands; pine-oak forests; and other forests. In Mexico, they are commonly found within pine-oak ecosystems (Gonzalez and Griswold 2013Gonzalez and Griswold 2013:
Gonzalez, V.H. and T.L. Griswold. 2013. Wool carder bees of the genus Anthidium in the Western Hemisphere (Hymenoptera: Megachilidae): diversity, host plant associations, phylogeny, and biogeography. Zoological Journal 168: 221ndash;425.).

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References