Acanthocaudus caudacanthus (Smith)

Kula, Robert R., Johnson, Paul J., Heidel-Baker, Thelma T. & Boe, Arvid, 2017, A new species of Acanthocaudus Smith (Braconidae: Aphidiinae), with a key to species and new host and distribution records for aphidiines associated with Silphium perfoliatum L. (Asterales: Asteraceae), Zootaxa 4236 (3), pp. 543-552 : 548

Acanthocaudus caudacanthus (Smith)

( Figs 2, 5 )

Trioxys (Acanthocaudus) caudacanthus Smith, 1944: 97 [USNM, examined]. Acanthocaudus caudacanthus: Mackauer 1960: 138 [revised combination].

Diagnosis. The mesosoma is entirely yellow in A. caudacanthus ; it is yellow except the mesonotum is brown in A. bicolor , and it is mottled yellow and brown or entirely brown in A. tissoti . The metasoma is entirely yellow in A. caudacanthus ; it is partially brown in A. bicolor and A. tissoti .

Distribution. Florida ( Smith 1944), Washington ( Pike et al. 2000), and Wisconsin ( Pike et al. 2000).

Hosts. Aphis gossypii , Uroleucon (Lambersius) erigeronense , Uroleucon (Lambersius) gravicorne ( Smith 1944) , Uroleucon sp. ex Aster sp. and Centaurea nigrescens ( Pike et al. 2000) .

Discussion. The validity of A. caudacanthus as a parasitoid of A. gossypii is questionable. It is the only record of a species of Acanthocaudus parasitizing species in a genus other than Uroleucon . It is based exclusively on a slide-mounted specimen in the USNM putatively reared from “melon aphid,” a common name used for A. gossypii , based on label data. Host remains are not associated with the specimen.

Figures

FIGURES 2 – 6. Species of Acanthocaudus. 2, Lateral habitus, A. caudacanthus; 3, Lateral habitus, A. tissoti; 4, Lateral habitus, A. schlingeri (junior synonym of A. tissoti); 5, Head and mesosoma, lateral view, A. caudacanthus; 6, Head and mesosoma, lateral view, A. tissoti. Scale bars: Figs 2 – 4 = 1.0 mm, Figs 5 – 6 = 0.5 mm.