1929] 
Oligolectic Bees and Favorite Flowers 
115 
ends 70 days before its Helianthese, 148 days, June 1-Oct- 
ober 26. P. pulchella, 48 days, begins 33 days after and ends 
12 days before its Helianthese, 93 days, July 15-October 15. 
P. helianthi, 38 days, begins 41 days after and ends 21 days 
before its Asterese and Helianthese, 100 days, July 24-Oct- 
ober 31. None of the Pterandrenas get pollen from the same 
Compositse. 
Other Short-tongued Oligoleges 
Macropis steironematis , 33 days, begin 12 days after and 
ends 36 days before Steironema , 81 days, June 16-July 18. 
Halictoides marginatus , 34 days, begins 39 days after 
and ends 1 day before Helianthus, 74 days, July 23-October 
4. 
Panurgidae. Anthemurgus passiflorse, 51 days, begins 16 
days after and ends 17 days before Passiflora lutea, 84 days, 
July 5-September 26. Pseudopanurgus compositarum , 54 
days, begins 43 days after and ends 2 days before its Aste- 
rese, 99 days, July 24-October 31. P. asteris , 62 days, begins 
35 days after and ends 8 days before its Asterese and Helian- 
these, 105 days, July 19-October 31. P. solidaginis, 86 days, 
begins 8 days before and ends 13 days before its Asterese 
and Helianthese, 91 days, July 11-October 4. But it begins 
79 days after and ends 27 days before the general Asterese 
and Helianthese, 192 days, April 23-October 31. P. albitarsis, 
100 days, begins 4 days after and ends 21 days before its 
Helianthese, 125 days, May 25-September 26. P. rudbeckise, 
43 days, begins 61 days after and ends 44 days before its 
Helianthese, 148 days, June 1-October 26. P. rugosus , 61 
days, begins 24 days after and ends 25 days before its Heli- 
anthese, 110 days, July 9-October 26. P. labrosus, 57 days, 
begins 19 days after and ends 28 days before its Helianthese, 
104 days, July 15-October 26. P. labrosiformis, 42 days, be- 
gins 54 days after and ends 31 days before its Helianthese, 
127 days, June 22-October 26. Calliopsis coloradensis , 31 
days, begins 3 days before and ends 18 days before its Aster- 
cse and Helianthese, 46 days, August 23-October 7. Verbe- 
napis verbense, 75 days, begins 37 days after and ends 25 
days before Verbena, 137 days, May 22-October 5. The flight 
