1925] Habits of the Hibiscus Bee , Emphor bombiformis 279 
4 , 31-2. — “As a typical case of an oligotropic bee , Emphor 
bombiformis may be mentioned. Both sexes occur in abundance 
on flowers of Hibiscus lasiocarpus, the female collecting the 
pollen, the males often spending the night in the flowers. The 
bees do not occur except when the Hibiscus is in bloom. Within 
several yards of the Hibiscus I have seen the female making 
nests in a dry bank, carrying water to soften the earth she was 
excavating. The bees coming out next year find the Hibiscus in 
bloom near by. The only visits to other flowers I have seen the 
bees make were to those in the neighborhood of the Hibiscus. 
Thus I have seen a single female sucking the nectar of Cephalan- 
thus occidentalis, and another that of V ernonia fasciculata, as well 
as a single male sucking nectar of Ipomoea pandurata. The out- 
side visits in no way modify the essential relation of the bee to 
the Hibiscus .” 
9 . — “The fact that Emphor bombiformis rests upon the water 
when drinking, mentioned under the above title by Frederick 
Knab (7) was observed in 1890 and was recorded in 2. It is 
fairly certain that the bees were not drinking in the ordinary 
sense, but that they consisted exclusively of females which were 
getting water to soften the earth in which they were making ex- 
cavations for their nests.” 
This passage is casually cited (11:588) under Knab, as if it 
related to “drinking” instead of carrying water, and in spite of 
the fact that Knab’s observation was not new. 
Phenology. — Hibiscus lasiocarpus blooms 59 days, July 20- 
Sept. 16. Emphor bombiformis, its oligolege, flies 53 days, July 
21-Sept. 11, the male 44 days, July 21-Sept. 2, the female also 
44 days, July 30-Sept. 11. The male is 9 days earlier than the 
female, which is about the average for males, 9.6 mentioned in 
10 . The female is 9 days later than the male, which is 13 less 
than the average for females given in 10 . This is one of 5 long- 
tongued bees in 10 , 341. Grossbeck and Nichols give Aug. 22, 
25 and Sept. 3. 
Flower visits (7). — $ c(2) — Malvaceae: Hibiscus lasio- 
carpus, H. militaris. 
