STOP
Early Journal Content on JSTOR, Free to Anyone in the World
This article is one of nearly 500,000 scholarly works digitized and made freely available to everyone in
the world by JSTOR.
Known as the Early Journal Content, this set of works include research articles, news, letters, and other
writings published in more than 200 of the oldest leading academic journals. The works date from the
mid-seventeenth to the early twentieth centuries.
We encourage people to read and share the Early Journal Content openly and to tell others that this
resource exists. People may post this content online or redistribute in any way for non-commercial
purposes.
Read more about Early Journal Content at http://about.jstor.org/participate-jstor/individuals/early-
journal-content .
JSTOR is a digital library of academic journals, books, and primary source objects. JSTOR helps people
discover, use, and build upon a wide range of content through a powerful research and teaching
platform, and preserves this content for future generations. JSTOR is part of ITHAKA, a not-for-profit
organization that also includes Ithaka S+R and Portico. For more information about JSTOR, please
contact support@jstor.org.
March, 1913-] Barber : Aquatic Hemiptera. 29
T. Carolina Linne.
Bronxville, N. Y., V (Woodruff) ; Yaphank, N. Y., VII ; Wading
River, N. Y., VIII ; Staten Island, IV, V, VI, VII, IX, X ; Newfound-
land, N. J., IX; Great Notch, N. J., V; Jamesburg, N. J, IX; Lake-
hurst, N. J., IV, 25, 1908, many individuals and a pair in copulation;
VI, VIII. Only two or three of our dragonflies have as long a season
as this, namely from April to October. We quote the following from
the " Preliminary List of the Dragonflies of Staten Island with notes
and Dates of Capture " (this Journal, Sept., 1898) : " On July 15,
1894, a male Tramea Carolina was flying over one of the Four Corners
iron mine ponds. Soon a female came and commenced dipping her
abdomen into the water. In a moment she was seized by the male and
they flew away. In a half hour they were back and went flying about
together, the male now and then suddenly letting go his hold and with
equal rapidity catching the female again by the neck. Other male
dragonflies flew after them and when the female stopped to lay eggs,
they annoyed her considerably. The chief among the disturbers was
a Libellula basalis. After a time the male Tramea left his mate and
she was quickly seized by the aforesaid Libellula basalis, after which
they flew about together for a considerable time. After letting go his
hold once and flying down the pond, the L. basalis returned and seized
the Tramea a second time."
AQUATIC HEMIPTERA.
By H. G. Barber,
Roselle Park, N. J.
The aquatic Hemiptera have excellent and frequently wonderful
adaptations to their environment, exhibiting among them most mar-
velous variability of construction for their life in or on the water.
The local, strictly aquatic species, belong to ten families of the hete-
ropterous Hemiptera. These for convenience of treatment of relation
of adaptations to habit may be grouped into (1) those which spend
their active existence on the surface of the water, (2) those which
habitually walk about upon some substratum beneath the water and
(3) those which are, for the most part, free swimmers.
30 Journal New York Entomological Society. t VoL XXI -
In all of these the most striking adaptations of structure are con-
nected with habits of locomotion, breathing and feeding, which are
variously modified to suit the particular environment referred to
above. With few exceptions these are all carnivorous and are
equipped with the short stout beaks necessary for piercing the tissues
and sucking the juices of animals. Correlated with this, the great
majority have the fore legs modified for seizing and holding the prey.
Although a few forms in the west have been recorded as occurring
in water strongly impregnated with various mineral salts, and a few of
our local forms in brackish water, they are for the most part strictly
fresh water forms. The species likely to occur in any body of water is
determined somewhat by the character of the water, the nature of the
current and the presence or absence of accumulated plant life. Some
species preferring the swift moving stream in which they seem to love
to sport against the force of the current ; others, and perhaps the
greatest number, are found only in still waters of ponds or the quiet
waters of bayed out parts of streams where they sometimes congre-
gate in immense numbers.
Quite a number of these aquatic hemiptera, notably members of
the families Belostomatidae, Corixidae and Notonectidae, have well-
developed wings and readily migrate from one body of water to an-
other and at such times, as has been frequently observed, are at-
tracted to bright lights. The great majority of species, however,
are fixed in their environment and though provided with wings are
frequently incapable of flight. Others are dimorphic as to wings.
In the Gerridse and allied families there occur a number of species
in both the winged and unwinged state.
The species which live actively upon the surface of the water
belong to the following families, Gerridae, Veliadae, Hydrometridae,
Neogeidae and Mesoveliadas. They have more or less elongated bodies
and slender legs. The beautiful ease with which they glide and skip
about over the surface of the water is due to the fine plush-like coating
of hairs on the feet and ventral parts of the body by means of which
they are enabled to enmesh a thin film of air which sustains their
weight on the surface film and keeps the body dry. Unlike the mem-
bers of the second and third groups the antennae are well developed
and exposed. As they breathe surface air they have no peculiar
method of respiration differing from terrestrial forms. Some of these
March, 1913.] Barber : Aquatic Hemiptera. 31
forms prefer the current of swiftly moving streams, but the majority
find more congenial surroundings on the surface of quieter waters
and a few may even make excursions upon land, where they may be
found in damp situations. They are all carnivorous, using the fore
legs for holding their prey, which usually consists of dead or living
insects. They all hibernate, concealing themselves at the bottom of
their retreat to reappear again on the surface early in the spring.
The forms which walk about on submerged sticks or stem of plants
beneath the water belong to the family Nepidae. The most striking
modification they present is a long respiratory tube through which
they may breathe surface air while the body is concealed beneath the
water. Their legs are long and slender and the fore legs are strong
and raptatorial for holding the prey. They more frequently occur
in shallow, sluggish streams or ponds well supplied with plant life.
Only three species are likely to occur in this vicinity belonging to the
genus Nepa and Ranatra.
The free swimming forms are more abundant, locally, than in the
two preceding groups. They usually have the hind pair of legs either
broadened or fringed with long hairs to resist the water and serve as a
swimming organ. Here are included the families Corixidae, Belo-
stomatidae, Naucoridae and Notonectidae — a group of carnivorous
forms, with the possible exception of Plea striola, having the custom-
ary short, stout beak. Some of these species are of economic impor-
tance as they frequently attack young fish or destroy their eggs.
The Corixidae, or water boatmen, are the most numerous in species
The hind legs are fringed with long hairs and their fore legs are pe-
culiarly modified, bearing characters which are largely used in their
specific differentiation. Carrying a supply of air beneath the elytra,
they may remain submerged for an indefinite period.
The Belostomatidae include some of the largest hemiptera known.
The second and third pairs of legs are broad and paddle like and
fringed with long hairs. The fore legs are developed into strong
clasping organs. They are good swimmers and strong fliers, fre-
quently attracted to light several miles from their breeding places.
The Notonectidae, or back swimmers, have the not much broadened
swimming hind tibiae fringed with hair and the modified clasping fore-
legs. The ventral surface is provided with a mass of long hairs which
enmeshes a supply of air for use beneath the surface. The species
32 Journal New York Entomological Society. [Vol. xxi.
differ considerably among themselves as to the quality of water they
may select for their abode; Notonecta undulata, for instance, may
occur in the foulest kind of pools, while others must have compara-
tively clean water.
The family Naucoridae includes some broad, ovate forms which
seem to prefer waters well stocked with vegetable matter. They have
the usual talon-like fore legs, but as their hind legs are neither broad-
ened nor fringed with hair, they are poor swimmers, depending more
upon walking about upon the submerged plants.
Of all of the Heteroptera perhaps the aquatic species have been
less well and accurately known to American entomologists than any
other group. This has been due to the fact that because of their
wide distribution, ease of collecting, and generally larger size they
received the attention of earlier systematists, who were satisfied to
give them but a brief and not distinctive characterization to make
them recognizable without an examination of the types. These types,
for the most part, having either been destroyed or deposited in mu-
seums abroad systematists have depended upon the meager descrip-
tions at hand, with the result that there has arisen considerable con-
fusion and uncertainty in fixing certain species. Especially is this so
in the family Corixidae.
AQUATIC COLEOPTERA.
By Chas. W. Leng,
West New Brighton, N. Y.
Few, if any, beetles are aquatic throughout all the stages of their
existence; even those commonly called water beetles pupate on land
and sometimes at least lay their eggs on leaves out of the water. The
beetles which are more or less aquatic in habit include the several
families of water beetles, the Parnidae and Elmidae, the tribe Dona-
ciini in Chrysomelidae, some tribes of snout beetles and a few other
smaller families. All of these exhibit some modifications of struc-
ture and vestiture in harmony with their aquatic life, modifications
that are on the whole more marked in the adults than in the larvae,
especially in the case of the plant-infesting species ; all exhibit a more
