Paranthidium

Taxonomy

Family: Megachilidae
Subfamily: Megachilinae
Tribe: Anthidiini
Genus: Paranthidium Cockerell and Cockerell, 1901
Subgenera: Paranthidium, Rapanthidium
Common name: none

Overview

Paranthidium are bees with robust bodies that range in body length from 7.5–11.0 mm (Michener 2007Michener 2007:
Michener, C.D. 2007. The Bees of the World (2nd ed.). Johns Hopkins University Press, Baltimore and London, 953 pp.). They are nonmetallic and have black or brown integumentintegument:
a tough, protective outer layer
with white to yellow abdominal, thoracic, or facial patterns (Michener 2007Michener 2007:
Michener, C.D. 2007. The Bees of the World (2nd ed.). Johns Hopkins University Press, Baltimore and London, 953 pp.). Some species have color patterning that is similar to that of a hornet (Wilson and Carril 2016Wilson and Carril 2016:
Wilson, J.S. and O.M. Carril. 2016. The Bees in Your Backyard: A Guide to North Americarsquo;s Bees. Princeton University Press, Princeton and Oxford, 288 pp.). The presence of pollen-collecting hairs on the female abdomen and other characters make them easy to identify as a bee on close inspection.

Diversity

Paranthidium contains approximately 8 species in 2 subgenera worldwide. Paranthidium jugatorium, occurs in the U.S. and is rare or absent in extreme southern Canada (Michener 2007Michener 2007:
Michener, C.D. 2007. The Bees of the World (2nd ed.). Johns Hopkins University Press, Baltimore and London, 953 pp.; Wilson and Carril 2016Wilson and Carril 2016:
Wilson, J.S. and O.M. Carril. 2016. The Bees in Your Backyard: A Guide to North Americarsquo;s Bees. Princeton University Press, Princeton and Oxford, 288 pp.). Two species are undescribed (Michener 2007Michener 2007:
Michener, C.D. 2007. The Bees of the World (2nd ed.). Johns Hopkins University Press, Baltimore and London, 953 pp.).

Diagnostic characteristics

(modified from Michener 2007Michener 2007:
Michener, C.D. 2007. The Bees of the World (2nd ed.). Johns Hopkins University Press, Baltimore and London, 953 pp.)

• Arolia present.
• Middle tibiatibia:
  the segment of the leg, between the femur and the tarsus
  with a convexconvex:
  curved outward
  , lobe-like carinacarina:
  a clearly defined ridge or keel, not necessarily high or acute; usually appears on bees as simply a raised line
  at apexapex:
  end of any structure
  .
• Omaular carinacarina:
  a clearly defined ridge or keel, not necessarily high or acute; usually appears on bees as simply a raised line
  absent.
• Preoccipital carinacarina:
  a clearly defined ridge or keel, not necessarily high or acute; usually appears on bees as simply a raised line
  absent.
• Pronotal lobes carinatecarinate:
  having keels or carinae
  or lamellatelamellate:
  thin, plate-like, often somewhat translucent structure
  .
• Propodeum propodeum:
  the last segment of the thorax
  with foveafovea:
  a depressed region of cuticle; in bees this depressed area is usually only very slightly hollow and usually on the face.
  behind the spiraclespiracle:
  a breathing pore, usually occurring on the third thorasic segment
  , except in the subgenus Rapanthidium.
• Male 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
  with laterallateral:
  relating, pertaining, or attached to the side
  combs (Paranthidium s. str.).
• 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
  trilobed, the median lobe always larger than the laterallateral:
  relating, pertaining, or attached to the side
  lobes.

May be confused with

Paranthidium may be confused with Dianthidium due to similar size, shape, and coloration, but can be easily distinguished because Paranthidium lacks omaularomaular:
angle between anterior and lateral surfaces of mesepisternum
and preoccipital carinacarina:
a clearly defined ridge or keel, not necessarily high or acute; usually appears on bees as simply a raised line
(Michener 2007Michener 2007:
Michener, C.D. 2007. The Bees of the World (2nd ed.). Johns Hopkins University Press, Baltimore and London, 953 pp.).

Known invasives

There are no known invasives.

Host associations

Paranthidium are generalists overall, but some show some level of preference for Asteraceae (Wilson and Carril 2016Wilson and Carril 2016:
Wilson, J.S. and O.M. Carril. 2016. The Bees in Your Backyard: A Guide to North Americarsquo;s Bees. Princeton University Press, Princeton and Oxford, 288 pp.).

Nesting behavior

Paranthidium are solitary bees that build nests in sandy soil by excavating their own burrows or using preexisting insect burrows, including inactive bee burrows (Evans 1993Evans 1993:
Evans, H.E. 1993. Observations on the nests of Paranthidium jugatorium perpictum (Cockerell) (Hymenoptera: Megachilidae: Anthidiini). The Pan-Pacific Entomologist 69: 319ndash;322.; Wilson and Carril 2016Wilson and Carril 2016:
Wilson, J.S. and O.M. Carril. 2016. The Bees in Your Backyard: A Guide to North Americarsquo;s Bees. Princeton University Press, Princeton and Oxford, 288 pp.). Thin resin walls line and partition the series of cells occurring in the burrow. Small pebbles may be placed between resin layers (Evans 1993Evans 1993:
Evans, H.E. 1993. Observations on the nests of Paranthidium jugatorium perpictum (Cockerell) (Hymenoptera: Megachilidae: Anthidiini). The Pan-Pacific Entomologist 69: 319ndash;322.).

Distribution

Paranthidium is endemic to the Western Hemisphere, and ranges from the U.S. south to Panama (Michener 2007Michener 2007:
Michener, C.D. 2007. The Bees of the World (2nd ed.). Johns Hopkins University Press, Baltimore and London, 953 pp.). The only species that occurs in the U.S., is P. jugatorium which occurs from the Atlantic Coast into the midwestern and southwestern U.S. This species has been further divided into four subspecies (Wilson and Carril 2016Wilson and Carril 2016:
Wilson, J.S. and O.M. Carril. 2016. The Bees in Your Backyard: A Guide to North Americarsquo;s Bees. Princeton University Press, Princeton and Oxford, 288 pp.). Paranthidium jugatorium jugatorium occurs from New York to the Midwest; P. jugatorium lepidum occurs in Kentucky and Virginia, south to Georgia, with records in northern Florida; P. jugatorium butleri occurs in Arizona; and P. jugatorium perpictum occurs in Colorado, New Mexico, and Arizona (Wilson and Carril 2016Wilson and Carril 2016:
Wilson, J.S. and O.M. Carril. 2016. The Bees in Your Backyard: A Guide to North Americarsquo;s Bees. Princeton University Press, Princeton and Oxford, 288 pp.). The remaining species in the genus occur in Mexico and Central America (Michener 2007Michener 2007:
Michener, C.D. 2007. The Bees of the World (2nd ed.). Johns Hopkins University Press, Baltimore and London, 953 pp.).

​Distribution map generated by Discover Life -- click on map for details, credits, and terms of use.

References

Evans, H.E. 1993. Observations on the nests of Paranthidium jugatorium perpictum (Cockerell) (Hymenoptera: Megachilidae: Anthidiini). The Pan-Pacific Entomologist 69:319-322.
 
Michener, C.D. 2007. The Bees of the World (2nd ed.). Johns Hopkins University Press, Baltimore and London, 953 pp.
 
Wilson, J.S. and O.M. Carril. 2016. The Bees in Your Backyard: A Guide to North America’s Bees. Princeton University Press, Princeton and Oxford, 288 pp.