The Genus Drepanaphis Del Guercio (Homoptera: Aphididae)

Smith, Clyde; Dillery, Dean

Taxonomic review of a group of aphids that includes a holotype from the Blue Ridge Parkway. The genus Drepanaphis Del Guercio is known only from North America. The usual host is Acer; however, 1 species occurs on Aesculus. The 17 described species, 4 of which are new, can be grouped into 5 homogeneous groups of 3 species each. The remaining 2 species seem to be more closely related to the monelli-group than any other. The utahensis-group includes utahensis Knowlton and Smith, granovskyi Smith and Knowlton, and simpsoni Smith. These are the only species which have pleural setae on the sixth abdominal segment of the nymphs and 2 pairs of frontal setae in the adults. The monelli-group includes monelli (Davis), spicata Smith, and knowltoni, new species, which are very similar morphologically in both nymphal and adult stages, but are distinctly separated from one another by locality and host. A fourth species, keshenae Granovsky, does not fit the monelligroup very well but is probably more closely related to it than to any other group. The acerifoliae-group contains acerifoliae (Thomas), carolinensis Smith, and sabrinae Miller. They differ from other species in bearing 4 pairs of conspicuous dorsal abdominal tubercles, but only 1 pair of frontal setae in the adults. The species in the parva-group, consisting of idaboensis, new species, saccbarini, new species, and parva Smith, are very similar morphologically as adults and nymphs but have distinct hosts. The most specialized group is the nigricans-group, which contains nigricans Smith, tissoti Smith, and choanotricha, new species. The nymphs in this group show a strong tendency toward loss of setae. All 3 species look quite alike when alive, and are small with relatively long antennae. The dorsal abdominal setae are distinctly expanded distally. D. kanzensis Smith is difficult to place with any certainty. It shares characteristics with the monelli-group as well as the parva-group. It is probably most closely related to the monelli-group. Keys and descriptions are given for all species.A closely related genus, Shenahweum Hottes and Frison, is similar to Drepanaphis but the siphunculi are truncate rather than swollen at the base as in Drepanaphis. Also, in Shenahweum the flange is weak and inconspicuous, and the sensorial pattern of a.s. VI is different. S. minutum Davis has the same habits as Drepanaphis species, and the nymphs have the same basic chaetotaxy.

The Genus Drepanaphis Del Guercio (Homoptera: Aphididae)

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