104 
Psyche 
[April 
Number of Species. — On account of having more species, 
and in spite of a lower average number of visits, the flies and 
lower Hymenoptera surpass the Lepidoptera; the Halictidae and 
Megachilidse surpass the Bombidae; the Andrenidse surpass the 
Euceridae; the Muscoidea surpass the Syrphidae; the Syrphidae 
and Bombyliidae surpass the Conopidae; the Eumenidae surpass 
the Sphecidae, Vespidae and Scoliidae; the Crabronidae and Pom- 
pilidae surpass the Vespidae, Philanthidae, Scoliidae and Bembicidae. 
Average Number of Visits. — In spite of the fewer species, the 
bees surpass the flies in average number of visits. The Bombinae 
surpass the Euceridae, Megachilini, Nomadidae, Osmiini or 
Epeolidae which have more species. The Halictidae make 1366 
more visits than the Andrenidae, although they have only five 
more species. 
Length of Flight. — The high average for Apis mellifera, 
Bombinae, Ceratinidae, Halictidae and Vespidae is associated 
with the long flight, the most important condition determining 
the visits of bees. Bees flying all season are 23 . 3 per cent of the 
species and make 51.2 per cent of the bee visits. 
Abundance. — Mere commonness is an important condition 
in determining the visits to flowers. Insects visiting 11 or more 
flowers are 27 . 1 per cent of the species and make 77 . 6 per cent 
of the visits. The bees, rubythroat and Lepidoptera are the 
only visitors which gain in percentage of visits over species. 
Bees gain in percentage of individuals over visits and all other 
jnsects lose. 
The following insect groups make more than 139.7 visits, 
one per cent of the total: 
Bees 6063 long-tongued 3061 short-tongued 3002. — Halic- 
tidse 1951, Megachilidse 786, Bombidae 764, Andrenidae 585, 
Euceridae 521, Nomadidae 272, Epeolidae 198, Ceratinidae 194, 
Prosopididae 166, Panurgidae 141, Colletidae 140. 
Flies 3775. — Muscoidea 1712, Syrphidae 1165, Bombyliidae 
370, Conopidae 238, Empididae 162. 
