As indicated in the preliminary outline of classification, this large
order has been divided into many orders by later entomologists. It has
also been divided, as indicated, into two grand divisions, the
Pseudoneuroptera, comprising those insects with incomplete
transformations, and the Neuroptera proper, comprising those insects
whose metamorphoses are complete. It will be convenient to discuss these
insects under these two heads.
_Pseudoneuroptera._--Spring-tails, Bird-lice, Stone-flies, White-ants,
Dragon-flies, May-flies.
[Illustration: FIG. 83.--A Spring-tail (_Degeeria lanuginosa_).]
The Spring-tails, Fish-moths, etc., representing the primitive stock
from which the higher forms have developed, have a varied habit and
hence are to be found in divers situations. The Spring-tails
(_Collembola_, etc.), occur in damp and moist places, usually in immense
numbers. The Fish-moths and Book-mites are common household pests, but
also occur outdoors under logs, boards, bricks, and rubbish of all
sorts. In houses they feed on the starch paste beneath wall-paper and
also on the starch in bookbindings and other domestic articles. They may
be collected at all seasons and a sieve is the only implement necessary.
[Illustration: FIG. 84.--A Mallophagan (_Trichodectes latus_). (After
Denny.)]
The Bird-lice or Mallophaga may be collected at all seasons on birds and
mammals. A number of species infest domestic animals, horses, cattle,
etc., but the majority of them can be found only by the examination of
domestic fowls and wild birds. The Stone-flies (_Perlidae_) are found in
the neighborhood of water courses and ponds, are very sluggish in
flight, and easily captured with the sweep-net. They are also attracted
to light. The Psocidae are a small family of certain degraded wingless
forms, comprising the Book-lice, which, as the name implies, infest
books, feeding on the starch of the binding. Others have ample wings and
closely resemble large Aphides. They occur on the trunks of trees and on
foliage, and feed on lichens and other dried vegetable matter. They are
gregarious in habit and frequently occur in immense numbers together. In
the case of the Termitidae or White-ants, their abundance renders their
collection an easy matter. Effort, however, should be made to discover
the different forms, the females and soldiers as well as the workers.
The former may be found in rotten tree trunks, but are very rarely met
with. In the tropics many species occur and construct curious nests,
either attaching them to the boughs of trees or building them in the
form of pyramids on the ground. The Dragon-flies (_Libellulidae_,) are
collected in the same way as the Diurnal Lepidoptera. They are very
swift flyers, and are practically always on the wing. Their collection
requires some degree of skill in the use of the net. A good method
consists in visiting, in the early morning, water courses in which the
larval and pupal states are passed, and capturing the adults just as
they issue from their pupal skins at the edges of the pond or stream. In
cold weather they are less active and may frequently be found clinging
to trees and plants, particularly in the vicinity of their breeding
places. May-flies (_Ephemeridae_) occur in immense numbers near their
breeding places in ponds and streams and are also attracted in large
quantities to electric lights. Their collection is therefore an easy
matter, but on account of the very fragile nature of these insects the
utmost care must be employed in handling them. The early states of all
the aquatic forms mentioned above may be obtained for breeding by the
use of the dip net by dragging it forcibly against water plants.
[Illustration: FIG. 85.--_b_, a May-fly (_Palingenia bilineata_); _c_,
its larva; _a_, a Caddis-fly (_Macronema zebratum_).]
[Illustration: FIG. 86.--A Dragon-fly (_Libellula_). (From Packard.)]
[Illustration: FIG. 87.--A Dragon-fly (_Agrion_). (From Packard.)]
_Neuroptera proper_ (Hellgrammites, Lace-wings, Ant-lions, Caddis-flies,
etc.)--Among the largest insects of this order are the Sialidae, which
includes the enormous Hellgrammite Fly, _Corydalus cornutus_. The larvae
of this insect are carnivorous and occur in streams, under stones, etc.
The adults may be collected in neighboring situations and are also
attracted to light. The Lace-wing flies (_Chrysopa_), Ant-lions, etc.,
are carnivorous as larvae, and occur, the former among the Aphides which
infest various plants and the latter at the bottom of pits in loose,
sandy soil. The adults may be obtained by general sweeping and are also
attracted to light. The most interesting insects of this order are the
Caddis-flies, on account of the peculiar and frequently very beautiful
cases constructed by their larvae, which it is important to collect. The
Caddis-flies breed in ponds and lakes and the adults may be collected in
such situations or at light. The larvae may easily be reared, and should
be collected for this purpose. Most of the insects named in this order
are extremely delicate and require great care in handling.
[Illustration: FIG. 88.--An Ant-lion, adult (_Myrmeleon_). (From
Packard.)]