116 
Psyche 
[August-October 
PHENOLOGY OF INQUILINE AND NEST-MAKING BEES. 
By Charles Robertson 
Carlinville, Illinois. 
Cases observed with a flight of only 1-10 days are excluded 
as fragmentary. Comparisons should be made with 6, 105-9. 
Colletes and Epeolus. — Colletes flies 224 days, Mar. 20-Oct. 
30, six together June 20-29 and Aug. 26-Sept. 5. It shows a 
maximum of 46.6 per cent June 21, 53.3 per cent flying in July 
and August. Epeolus flies 148 days, May 29-Oct. 23, four to- 
gether Aug. 29-Sept. 5. Its flight is 76 days shorter than that 
of Colletes. C. incequalis lacks only 3 days of completing its 
flight of 81 days, Mar. 20-May 31, before Epeolus begins. Evi- 
dently it is not infested by any Epeolus. 
E. interruptus, May 29-June 19, is evidently an inquiline of 
C. cestivalis, May 8-July 1. It may, however, belong to C. brevi- 
cornis, May 29-June 29, or to both. E. bifasciatus, June 12-Oct. 
3, is probably an inquiline of C. latitarsis, June 13-Oct. 1, and 
perhaps also of C. willistonii, May 28-Sept. 5; E. pusillus, Aug. 
26-Oct. 23, of C. americanus, Aug. 18-Oct. 30; E. autumnalis, 
Aug. 29-Oct. 13, of C. compactus, Aug. 26-Oct. 21. The former 
pair are small, the latter large. C. armatus, Aug. 17-Oct. 7 may 
be infested also by E. autumnalis or by E. coreopsis, Aug. 20- 
Sept. 5. 
Grsenicher (3) says Argyroselenis minimus is an inquiline of 
C. eulophi, which flies 146 days, May 28-Oct. 30. I have taken 
A. minimus but once, July 8. 
Mecaghilini and Ccelioxys . — The Megachilini, 14 species, fly 
165 days, May 11-Oct. 22, all together for 8 days, July 3-10. 
Six species of Ccelioxys fly 161 days, May 12-Oct. 19, all together 
for 42 days, July 4-Aug. 14. 
Megachile brevis, May 15-Oct. 22, may be infested by C. 
octodentata, May 12-Oct. 19 (I think it has been recorded in Ent. 
News) and M. mendica, May 16-Oct. 11, by C. sayi, May 21-Oct. 
4. Xanthosarus latimanus, May 28-Oct. 20, is infested by C. 
rufitarsis, July 4-Oct. 19, according to Grsenicher (2), and I have 
