Genus Thyreodon

Thyreodon Brullé, 1846

6 spp. recorded north of Mexico:(1)

1. T. apricus (s. TX; primarily neotropical)

2. T. atricolor (widespread, primarily eastern)

3. T. fernaldi ("southern USA": including AZ, CO)

4. T. ornatipennis (restricted in "southern USA" including NM; primarily neotropical)

5. T. umbrifer (FL)

6. T. rivinae (s. TX; primarily neotropical including northern Mexico)

1. T. apricus - an entirely black species, including flagella, body, and wings. The wings may bear blue reflections, but the body, itself, is entirely non-metallic.

2. T. atricolor - a black species with orange antennae and generally no extensive markings

3. T. fernaldi - a black species with orange antennae and often a reddish band on the 3rd and 4th abdominal segments (often including parts of the 2nd and 5th)

4. T. ornatipennis - the only extensively ferruginous species with orange antennae, a reddish head, and reddish markings extending to the abdomen. The wings often have a fulvo-hyaline stripe or spot, though this is variable.

5. T. umbrifer - a dark fulvous-and-black species with uniformly brownish wings. Only reported in Florida.

6. T. rivinae - a largely black species similar to T. atricolor or T. apricus but with an unpigmented discosubmarginal ("horse-head") cell

Eastern Canada, Eastern and Southern parts of the US

Large mimics of aculeate wasps, particularly tarantula-hawk wasps and allied Pepsini. T. ornatipennis is suggested as a mimic of the paper wasp Polistes canadensis.

Therion and Heteropelma spp. can have similar coloration but are rather smaller species. The females are easily separated by the longer, more visible ovipositor. All but 2 spp. are separated by having yellow-banded hind legs (2 species of Therion have entirely black legs, per remarks by Bob Carlson). The hind tarsi of Heteropelma are also differently proportioned, with the first tarsus considerably longer than the subsequent tarsi. The entire hind leg is also proportionally longer in Therion than in Thyreodon.

Left to right: T. morio, T. nigripes, T. tenuipes, and Heteropelma datanae