Diastrophus Hartig, 1840

Nastasi, Louis F., Buffington, Matthew L., Davis, Charles K. & Deans, Andrew R., 2024, Key to the North American tribes and genera of herb, rose, bramble, and inquiline gall wasps (Hymenoptera, Cynipoidea, Cynipidae sensu lato), ZooKeys 1196, pp. 177-207 : 177

Diastrophus Hartig, 1840

Type species.

Cynips rubi Bouché, 1834.

Diagnosis.

Mesoscutum generally weakly sculptured and without abundant strong setigenous punctures. Notauli complete and strong throughout. Mesopleuron sculpture smooth to striate. Fore wing with marginal cell open. Metasoma never with syntergite.

Note.

Diastrophus contains 14 North American species ( Nastasi and Deans 2021). Many species induce galls on Rubus L., although the herbaceous genera Fragaria L. and Potentilla L. are also used. Diastrophus smilacis Ashmead, 1896 and its supposed inquiline, Periclistus smilacis Ashmead, 1896, were previously believed to be associated with Smilax L., making D. smilacis the only cynipid known to induce galls on a monocot plant ( Gates et al. 2020). However, Gates et al. conclude that this association was erroneous, and the true gall inducer on Smilax is in fact a eulophid wasp ( Chalcidoidea : Aprostocetus smilax Gates & Zhang). The biological associations of Diastrophini therein are still atypical as Periclistus inquilines are generally associated with the tribe Diplolepidini . Our own examination of the type material of D. smilacis and P. smilacis (deposited in the USNM) confirm that they are indeed placed in the appropriate genera, although the status of either species and their biological relationships remain suspect and require further investigation.

Galls of Diastrophini (Figs 92-94 ) can be collected for rearing in the fall, winter, or spring. As in Aulacideini , galls on herbaceous hosts are best collected after host plants have senesced, and adults of all Diastrophus emerge in spring and summer.

North American species (Nastasi and Deans 2021):

1. Diastrophus austrior Kinsey, 1922

2. Diastrophus bassettii Beutenmüller, 1892

3. Diastrophus cuscutaeformis Osten Sacken, 1863

4. Diastrophus fragariae Beutenmüller, 1915

5. Diastrophus fusiformans Ashmead, 1890

6. Diastrophus kincaidii Gillette, 1893

7. Diastrophus nebulosus (Osten Sacken, 1861)

8. Diastrophus niger Bassett, 1900

9. Diastrophus piceus Provancher, 1886

10. Diastrophus potentillae Bassett, 1864

11. Diastrophus radicum Bassett, 1870

12. Diastrophus smilacis Ashmead, 1896

13. Diastrophus tumefactus Kinsey, 1920

14. Diastrophus turgidus Bassett, 1870

Figures

Figures 87 - 95. 87 galls of Antistrophus pisum on stem of Lygodesmia juncea (Asteraceae: Cichorieae), photographed by Chris Friesen (https: // www. inaturalist. org / observations / 95588437) 88 galls of Antistrophus rufus in dissected stem of Silphium laciniatum (Asteraceae: Heliantheae), photographed by Andy Deans (https: // www. inaturalist. org / observations / 64708490) 89 gall of Antistrophus silphii on apical stem of Silphium integrifolium (Asteraceae: Heliantheae), photographed by Andy Deans (https: // www. inaturalist. org / observations / 64708191) 90 galls of Diplolepis polita on leaves of Rosa sp. (Rosaceae: Roseae), photographed by Garth Harwood (https: // www. inaturalist. org / observations / 165442438) 91 gall of Diplolepis californica on Rosa sp. (Rosaceae: Roseae), photographed by Mary K. Hanson (https: // www. inaturalist. org / observations / 115655737) 92 gall of Diastrophus potentillae on Potentilla simplex (Rosaceae: Potentilleae), photographed by Tom Murray (https: // www. inaturalist. org / observations / 134669544) 93 gall of Diastrophus nebulosus on stem of Rubus sp. (Rosaceae: Rubeae), photographed by Pam Curtin (https: // www. inaturalist. org / observations / 174007397) 94 galls of Diastrophus kincaidii on stems of Rubus parviflorus (Rosaceae: Rubeae), photographed by Adam Heikkila (https: // www. inaturalist. org / observations / 173314109) 95 galls of Phanacis taraxaci on petiole of Taraxacum officinale (Asteraceae: Cichorieae), photographed by Nathan Earley (https: // www. inaturalist. org / observations / 174118397).