THE HyMENOPTERA OF MINNESOTA 147 
though lacking the locality label. We have, in this publication, cred- 
ited to our state fauna only those individuals labelled as collected here, 
or which have been reported on indisputable authority as occurring 
within the state. Manifestly many times more species occur in this 
state than are indicated in this publication. 
An excellent account of egg laying of gall flies may be found in 
Volume 3, Proceedings of the Entomological Society of Washington 
and in Kelloge’s “American Insects.” Howard’s “Insect Book,” pp. 
26-28 has an interesting description of the Vespidae, while the valu- 
able observations of the Peckhams may be found in the Wisconsin 
Geological and Natural History Survey Bulletin No. 2, Scientific Series 
No. 1. In this work under the headings, “The Little Fly Catchers,” 
“The Toilers of the Night,” “Enemies of the Orthoptera,” “The Bug 
Hunters,” “Some Grave Diggers,” and other more technical titles, they 
discuss the O-vrybelidae, the Crabronidae, the Trypoxylonidae, the 
Sphecidae, the Astatidae, Cerceridae and other families. The student 
is referred to Page 12 of Howard’s Insect Book and to Volume VI of 
the Cambridge Natural History for the habits of Andrena. Howard’s 
Insect Book also contains a good account of the leaf-cutting bee, the 
life history of bumble bees and the habits of the small carpenter bee, 
as well as furnishing the student with a large series of photographs 
of pinned Hymenoptera. The student of the order cannot afford to 
miss the valuable material found in Fabre’s “The Bramble Bees and 
Others,” “The Mason Bees,” and “The Hunting Wasps.” An abun- 
dance of other matter of a popular nature pertaining to Hymenoptera 
is available to students, and technical synopses of the group and de- 
scriptions of genera and species occur in our leading entomological 
journals. 
CHARACTERISTICS OF HYMENOPTERA 
This order is characterized by the presence of four wings, mem- 
branous, and for the most part, translucent, and with but few cells. 
The hind wing of each side, is, in flight, more or less firmly fastened 
to the front wing by a series of hooks on the front edge of the former, 
which articulates with a fold on the rear édge of the front wing. The 
mouth parts of the adults are adapted for biting and sucking. The 
ovipositor of the female is usually modified to form a sting, piercer or 
saw. 
Hymenopterous insects have a complete metamorphosis, i.e., dis- 
tinct egg, larval, pupal and adult stages. The larva, frequently re- 
