Four Burrowing Lycosa (Geolycosa Montg., Scaptocosa Banks) Including One New Species
International Journal of
,
VOL. XIX.
No. Z
MONTG. NEW
BY J. H. EMERTON
Boston
Mass.
In PsYCH., Vol. 1877, S. H. Scudder described the burrowing spider of the Atlantic seacoast under the name Lycosa arenicola, which was preoccupied by Cambridge in the "Spiders of Dorset" in 1875. It was again described by George Marx in the American Naturalist in 1881 as Lycosa pikei. The upland species of a b Fig. 1. First and second legs; a, pikei, b, nidifex, c, missouriensis, d, wrightii.
Pehe
[April
This group is distinguished, as mentioned by Banks in his
description of Scaptocos in Journ. N. Y. Ent. Soc., 1904, by the
absence, in females only, of spines on the upper side of tibia III
and IV and by definite black markings on the under side of legs
I nd II in both sexes. In pikei the black extends the whole
length of legs I and II including the coxe. In nidifex it covers
four terminal joints. In missouriensis it covers three terminal
oints nd in wrightii three joints of leg I and two and part of the
third of leg II. Fig 1. In this group the first leg is
proportionally thicker in both sexes than in the other Lycoside. In the
.
males the first leg is three times at long as the cephalothorax in
nidifex and wrightii and two and three-fourths times as long in
missouriensis and pikei. In females it is two and a half times as
long in nidifex, two and a quarter in wrightii, two and a fifth in
pikei and twice in missouriensis.
L. pikei lives in sandy country near the seashore from Maine.
to New Jersey; L. nidifex along the eastern coast from Maine
to Georgia and westward as far as Albany, N. Y., and Atlanta,
Ga.; missouriensis along the Great Lakes in Ohio, Indiana
and Illi,nois and south to Missouri and North Carolina; L.
wrightii in sandy country along the Lakes from the eastern end
of Lake Erie near Buffalo to Chicago, Ill.. and south to the
middle of Illinois, along the Illinois River.
In this group the burrowing habit is so far developed that,
excepting adult males during the mating season, their whole life is
passed mder ground or within a short distance of the mouth of
the burrow. As soon as the young leave their mother they make
burrows of their own proportioned to their size. The digging is
done by covering the sand with silk enough to hold the grains
together and it is then gathered into pellets of convenient size
and carried in the mandibles to the mouth of the burrow, where
lig. 8. Lycosa nidifex sitting in the mouth of its burrow.
it is thrown outward by the ends of the front feet and on open
sand the pellets may be seen in a circle of three or four inches
the front half of the body.out over the edge of the hole and the
radius around the hole. When watching for prey, they sit with
legs turned under. Fig. They are sensitive to the slightest
movements on the ground, and vhen down in their burrows will
notice the walking of an insect within an inch or two of the hole
and come quickly to the top. The movement of a straw on the
surface will sometimes deceive them and bring them to the mouth
of the hole.
Zycosa nidifex digs often in sod and makes a "turret" around
the mouth of the burrow, sometimes only a narrow ring of dead
grass, but often rising an inch or more above the surface of the
ground and covered with straw, chips or any fine, loose material
within reach. When watching, the spider sits in the top of the
turret. Fig. 8. L. missouriensis also habitually makes a turret,
Z. pikei makes no turret except a slight ring .where there is much
low or high, according to the material and surroundings. Fig 4.
loose material blowing near the hole. Fig. In open sand it
sometimes makes a flat collar of silk over the surface an inch wide
around the hole. L. wrightii also prefers to dig in open sand and
makes no turret or only a rudiment of one.
L. nidifex matures in May, the other species in August and
September. The males all die before winter. Both sexes of all the
species pass the winter half grown. In nidifex they mature early
enough to lay their eggs the next summer but the other species
do not mature until late and the fertilized females live over a
sec
Emerton--Four [urrowing Lycosa
ond winter and lay eggs in May or June. The burrows are not
closed during the winter except as the weather accidentally
flattens the lining around their mouths and makes .the opening smaller.
The spiders remain torpid at the bottom, unhurt by the freezing
of the soil around them
Lycosa pikei Marx.
Pl. 4, Figs. 1, la, lb, lc.
The name arenicola was preoccupied by O. P. Cambridge in the
"Spiders of Dorset," 1875. In Trans. Conn. Acad., 1885, I have
confounded this species with L. nidifex and the description given
there applies in part to both species. This mistake has been
continued by T. H. Montgomery in Proc. Acad. Nat. Sci.,
Philadelphia, 1904, and by R. V. Chamberlin in Proc. Acad. Nat. Sci.,
Philadelphia, 1908. The differences between this species and
nidifex are described in my supplement to N. E. Spiders, Trans. Conn.
Acad., (...truncated)