Scoliidae

Taxonomy

Order: Hymenoptera
Family: Scoliidae Latreille, 1802
Family common name: scoliid wasps, flower wasps, mammoth wasps, scarab hawks, scarab hunters

Background

Scoliid wasps are solitary parasitoids of scarab beetle larvae. They may be important biocontrol agents, as many of the beetles they prey upon are pests, including the Japanese beetle. This family includes some of the largest known wasps, such as Megascolia procer, with a wingspan of 11.6 cm (4.5 in).

How to separate from Asian giant hornet

  • In North America, scoliids range in size from small to approximately ¾ the size of an Asian giant hornet
  • Many species are black with yellow or orange markings
  • Many scoliids are densely covered in long spines or hairs

Distribution

There are about 20 species found in North America.

Distribution of Scoliidae by GBIF: https://www.gbif.org/species/4351

Diagnostic characteristics

  • They are black, often marked with yellow, orange or red bands or spots
  • The wing membrane finely longitudinally wrinkled, particularly towards the apex
  • Body length 10–50 mm
  • Mesosternum and metasternum wide and divided by a transverse suture
  • Hind coxae widely separated
  • Males are slenderer and more elongated than females, with significantly longer antennae
  • Males have 3 spines protruding from with apex of the metasoma

Diversity

The family Scoliidae contains 560 species of wasp worldwide (Osten 2005).

Host/prey associations

Scoliid larvae are parasitoids of ground-dwelling scarab beetle larvae. The adult wasps feed on nectar.

Nesting and general behavior

Scoliid wasps are solitary parasitoids of scarab beetle larvae. Females burrow into the ground in search of these larvae. They use their sting to paralyze it and then lay an egg on the paralyzed beetle larvae. Male scoliid wasps patrol territories and try to mate with any females emerging from the ground (Hurd 1952).

Known invasives

Campsomeriella annulata and Micromeriella marginella modesta were introduced to control the Japanese beetle in the eastern United States, but neither species became established.

<p><em>Megascolia</em> sp.; photo by Frank Vassen, Flickr</p>
<p><em>Megascolia</em> sp.; photo by gailhampshire, Flickr</p>
<p><em>Megascolia</em> sp.; photo by S. Rae, Flickr</p>
<p>Scolidae sp.; photo by Ian Jacobs, Flickr</p>
<p>Scolidae sp.; photo by tdlucas5000, Flickr</p>
<p><em>Campsomeris</em> sp., lateral view; photo by Todd Gilligan, USDA APHIS PPQ ITP</p>
<p><em>Crioscolia alcione</em>, dorsal view; photo by Todd Gilligan, USDA APHIS PPQ ITP</p>
<p><em>Colpa pollenifera</em>, lateral view; photo by Todd Gilligan, USDA APHIS PPQ ITP</p>
<p>Scolidae (<em>Crioscolia alcione</em>) (left) compared to <em>Vespa mandarinia</em> (right), dorsal view; photos by Hanna Royals and Todd Gilligan, USDA APHIS PPQ ITP</p>