Extracted from THE POLLEN-COLLECTING BEES OF THE ANTHIDIINI OF CALIFORNIA (Hymenoptera: Megachilidae) by Grigarick A., A. (1968). |
D. platyurum is morphologically very close to ulkei and desertorum. The punctation of tergum VII of the male of platyurum is denser than that of desertorum, and the apex of sternum VI (fig. 166) is narrower than ulkei. The apex of the gonostylus of the genitalia is nearly right angled on platyurum as contrasted to the oblique angle of this structure on ulkei. The interstitial lines of the mesoscutum of the female of platyurum appear polished, which contrasts with the heavily sculptured lines of ulkei.
Dianthidium platyurum mohavense
Full, orange-yellow maculations separate moČhavense from the lighter colored and less maculated nominate subspecies. Intergradation of color and patČtern of these subspecies occurs in Inyo and Kern counties and future collections may suggest a change in subspecific designation. The extent of maculations within this species exhibits a reversal of the north to
south clinal pattern of more extensive maculations shown in other species.
D. playturum mohavense is known from seven males and seven females from the Transverse ranges, western foothills of the Sierra Nevada Range and San Joaquin Valley of California.
Dianthidium platyurum platyurum
The species was described from a pale yellow form in Baja California. The subspecies p. platyurum is designated in this paper to include those populaČtions having cream to pale yellow maculations which includes the pale yellow p. bacilifrons. A reddish-brown color is occasionally present on the subapical margins of the terga I to III on both sexes, but there
is no observed correlation between this color and geography. The extent of maculation varies within this species, with the most extensive pattern being associated with the bright yellow subspecies p. mohavense.
Eighteen males and 42 females of p. playturum were examined from collections in California south of the Transverse ranges and east of the Sierra Nevada. The biology of this species is unknown; but because of its morphological similarity to ulkei, one could speculate that it would build a nest utilizing natural cavities. D. p. platyurum has been collected on species in five plant families but primarily on members of the Compositae.
Updated: 2019-02-18 16:41:42 gmt