1896.) Flowers and Insects. 75 
Dirptera—ombylide : (1) Anthrax alternata Say; Syrhpida: (2) Par- 
agus tibialis Fll.; (3) P. bicolor F.; (4) Pipiza pulchella Will.; (5) Chry- 
sogaster nitida Wd.; (6) Allograpta obliqua Say; (7) Spaerophoria 
cylindrica Say; (8) Syritta pipiens L.; Zachinide: (9) Cistogaster im- 
maculata Mcq.; (10) Miltogramma argentifrons Twns.; Muscide: (11) 
Lucilia cornicina F.; (12) Cyrtoneura sp. 
YMENOPTERA — Andrentde: (13) Prosopsis pygmaea Cr. 9; Pom- 
pilide: (14 )Pompilus relativus Fox.—all sucking. 
HEMIPTERA--Coreida : (15) Chariesterus antennator F., s. 
SALIX Tourn.—The flowers of willows are dioecious and 
entomophilous, but Warming (21) regards S. herbacea and 
some other species as anemophilous in Greenland. In the 
Alps, according to Miiller (15), S. Aerbacea secretes abundant 
nectar and is visited by insects. Kerner (24) observed some 
species to be proterogynous, with the result that at first they 
could only receive pollen from flowers of other species and 
consequently produced hybrids. 
Sprengel (1) regarded the staminate catkins as being more 
conspicuous than the pistillate in order that the latter might 
thus be more likely to be visited by insects which had first be- 
come dusted with pollen from the staminate flowers. While 
tis a fact that the staminate catkins are more attractive to 
insects, and, in spite of Bonnier’s (11) statements to the con- 
ay, are more abundantly visited by them, it can hardly be 
aint 
than the others, | have often noticed that the catkins of 
more brightly colored than in any of our species of Salix. 
the a their readily accessible nectar and exposed pollen, 
i catkins are especially attractive to the less specialized 
i entd@) and to the flower flies (Syrphide) and in 
dant of the cases given in the table these are the most abun- 
Ex Suests, together forming a majority of all the visitors. 
tl “Pt for the services of these insects there seems to be lit- 
€ reaso 
Sect groups, except the Ampide, have more species 
fason. I suspect that, whenever a satisfactory 
ts of a willow is made out, it will show a prepon- 
Andrenide and Syrphida, unless there is some 
in the insect fauna of the region. 
Owing table gives the results of observations made 
Peculiarity 
he fol] 
