APRIL, 1900. GRAENICHER— FERTILIZATION OF FLOWERS, ETC. 
81 
D. COLEOPTERA. 
Coccinellidae : (79) Adalia 2-piinctata, L. ; Chrysomclidae : 
(80) Diabrotica vittata, S. ; Curculionidae : (81) Smicronyx cor- 
jiiciilafiis, F. — all s. 
E. Hemiptera. 
Capsidae: (82) Lygiis pratensis, L. ; Pyrrhocoridae : (83) 
Dysdcrciis, sp.; Lygaeidae: (84) sp. — all s. 
The vast majority of the visitors is made up of the hymenop- 
terous insects (mostly bees) and flies taken together, the 
hymenoptera being represented by thirty-eight species, as are also 
the flies by thirty-eight; these two orders together giving a total 
of seventy-six species, and leaving only eight species to be dis- 
tributed among the remaining three* orders in the following pro- 
portion, two butterflies (Lepidoptera), three beetles (Coleoptera), 
and three bugs (Hemiptera). 
Among the bees we notice seven species of the highly special- 
ized or long-tongued bees of the family Apidae, and most prom- 
inent among these are three species of Bomhus (bumble-bee), 
which, at this early period^ are present in the female sex only, the 
workers and males appearing much later in the season. The 
honey-bee (Apis inellirfica, L.) is a frequent visitor, especially on 
the staminate catkins, sucking honey and collecting pollen, but is 
in our part of the country never present in such numbers as to 
monopolize the staminate catkins and drive off most of the other 
visitors from the staminate flow^ers, as has been observed by 
Robertson (7) in Southern Illinois on SalLv hitmilis, Marsh., an 
early flowering willow. The three remaining species of the higher 
bees are two species of Osmia, bees having the pollen-collecting 
apparatus on the low^er surface of their abdomen and one species 
of Nomada. 
Of all the insects frequenting the willow-blossoms, none attain 
such an importance as the less-specialized bees — the Andrenidae. 
Eighteen species are credited to this family, the majority of them 
belonging to the genera Andrena and Halictus and leaving only 
one species to each of the remaining genera — Parandrena, 
Sphccodes and CoUetes. Many species of Andrena have their 
time of flight during the spring months, and depend to a great 
extent on the flowers of the different wdllow-species for their sup- 
ply of honey and pollen. A few species of Andrena and our 
single species of Parandrena rely even exclusively on willow- 
blossoms for their supply of pollen, and are never observed collect- 
ing pollen on any other plant than on certain species of Salix, al- 
though they resoit to other flowers for nectar. A bee obtaining 
(7) C.Robertson. Flowers and Insects. XV. Bot. Gazette. VoL XXI (1896) p 78. 
