Hayden Grasshopper
Derotmema haydeni (Thomas)
Link directly to photos of adults, nymphs,
and eggs.
Distribution and Habitat
D. haydeni continental distribution map
Wyoming distribution map
The Hayden grasshopper has a wide geographic range in western North
America. It inhabits the mixed-grass, shortgrass, desert, and bunchgrass
prairies. In these divisions of vegetation it usually occupies disturbed
land with a high percentage of barren area. It is frequently found in prairie
dog towns, at the sides of county and ranch roads, in abandoned fields,
and in vacant city lots.
Economic Importance
The Hayden grasshopper causes little damage to rangeland forage. Densities
of this grasshopper are usually low, and it feeds mainly on forbs.
Food Habits
This grasshopper appears to prefer certain forbs. In laboratory preference
tests, adults clearly preferred leaves of dandelion to leaves of blue grama,
western wheatgrass, prostrate knotweed, and Russian thistle, but fed nearly
as well on downy brome as dandelion. In Montana it has been observed to
feed on common purslane. Crop contents of one nymphal and five adult specimens
collected in the shortgrass prairie of the Pawnee Grassland (Colorado)
consisted of 69 percent plains bahia, 10 percent scarlet globemallow, 7
percent needleleaf sedge, and 6 percent fringed sagebrush; three other
forbs and three grasses made up the remaining items (8 percent).
Several direct observations of its feeding indicate that it feeds on
dry plant litter and on recumbent green leaves from a horizontal position
on the ground. In the laboratory it was observed feeding on the edge of
a green dandelion leaf. Further observations are needed to find out how
it attacks upright plants such as plains bahia and scarlet globemallow.
Dispersal and Migration
No observations of dispersal or migration by this grasshopper have been
made. However, its possession of long wings that extend beyond the abdomen
in both males and females suggests that it has the capacity to fly long
distances.
Evasive flights of the species have been observed. Their distances range
from 2 to 6 feet and their heights from 4 to 10 inches. The flights may
be straight or the grasshopper may make a right angle turn midway in the
flight. Flights begin from the ground and end on the ground. They may have
a smooth trajectory or they may end abruptly by a quick turn of the flying
insect. In the latter trajectory the grasshoppers appear to drop out of
the air to the ground facing in various directions on landing.
Identification
The Hayden grasshopper is a medium-sized, bulbous-eyed, bandwinged species
( Fig. 6 and 7). General body color is tan and
brown. The tegmina are marked with many fuscous spots; the hindwings have
a broad dark band that extends from front to hind margin and a red or yellow
basal area ( Fig. 9). The disk of the
pronotum has prominent ridges and nodules; the median carina is distinct
and cut twice, once near the middle and once in front of the middle; the
posterior margin of the disk is angulate.
The nymphs are identifiable by their shape, structures, and color patterns.
First instar nymphs are distinctively marked by four shiny black nodules
on the front of the head and two on the pronotum (
Fig. 1). A flat black patch is located on the head behind each compound
eye. Below these marks, a broad yellow or light tan band runs around the
head and onto the lateral lobes of the pronotum. The band becomes less
clear, and the nodules flatten and become less dark and shiny in instars
II and III and disappear in instars IV and V.
Other distinguishing characteristics of the nymphs (
Fig. 1-5) include the following:
1. Head with protruding, bulbous compound eyes; fastigium steeply slanted;
antennae filiform.
2. Thorax raised in instars I to III, giving a humpbacked appearance
to the early instars. Pronotum with distinct median carina, cut twice;
disk rugose and nodulate, more so in older instars; posteroventral angle
of lateral lobe rounded.
3. Bottom of abdomen cream or tan with a pair of rust-colored spots
on each segment ( Fig. 8), spots
fainter and fewer in instar I, spots more numerous in instar V.
4. General body color brown and tan.
Hatching
The Hayden grasshopper is considered a late- hatching species. The eggs
hatch four to five weeks after those of the bigheaded grasshopper, Aulocara
elliotti. In eastern Colorado and eastern Wyoming hatching occurs during
June. No investigation of embryonic development of this species has been
made.
Nymphal Development
The five nymphal instars require about 40 days to develop to the adult
stage. Because of the extended hatching time, as many as three different
instars may be found in the habitat during much of the nymphal period.
In eastern Colorado and Wyoming adults begin to appear during the last
few days of July.
Adults and Reproduction
The adults remain in the same habitat in which they developed as nymphs.
They live active lives during August and September. Little is known about
their reproductive biology. Observations have been made on courtship, which
appears to vary slightly among populations studied in Colorado, Utah, and
California. However, at all three locations courtship was rather short
and simple and usually consisted of the male tipping his hind femora, stridulating
one to three times, and then mounting the female.
No information is available on when females begin to oviposit, how many
eggs they produce during their life, or where they oviposit. In the laboratory,
females readily oviposit into a container of bare soil. They take approximately
one hour to complete an oviposition. The pods are curved, about an inch
long, and contain 16 to 17 pale yellow eggs 4.3 mm long (
Fig. 10). There is one generation annually.
Population Ecology
No special study of the ecology of this grasshopper has been undertaken.
From other studies we do know a few facts about their population ecology:
the species has a wide geographic range in the West, densities are usually
low, and dispersion of individuals is concentrated in the bare areas of
mixedgrass and shortgrass prairies. In shrub-grass habitats with a preponderance
of bare areas, individuals are scattered throughout the habitat. Densities
of clumped adults are usually no more than one per square yard, but on
occasion they may become higher. In the Marfa prairie of the Big Bend Region
of Texas, Ernest R. Tinkham (1904-87), a well-known entomologist and naturalist,
found this species "quite abundant" on bare adobe patches.
Daily Activity
The Hayden grasshopper is a ground-dwelling insect. At night nymphs and
adults rest horizontally on the ground surface either under a canopy of
plants, or exposed without any cover. Approximately one hour after sunrise
both nymphs and adults begin to bask in the warming rays of the sun. They
turn a side perpendicular to the rays and lower the hindleg of the exposed
side to the ground. After basking for about two hours, adults begin normal
activities of walking about on open ground, occasionally producing femur-tipping
movements, feeding, and mating. These activities continue until ground
temperatures in the afternoon become too hot (120°F and above). Then
they seek the shade of vegetation and rest horizontally on the ground surface.
After soil temperatures moderate they again become active. They may come
out into the sun too soon and take a stilt posture in which they hold their
bodies off the hot (101°F) ground surface. In the evening they bask
again and finally take their night time positions sitting horizontally
on the ground surface.
Selected References
Anderson, N. L. 1973. The vegetation of rangeland sites associated with
some grasshopper studies in Montana. Montana Agr. Exp. Stn. Bull. 668.
Otte, D. 1970. A comparative study of communicative behavior in grasshoppers.
Misc. Publ. Mus. Zool., Univ. Michigan, No. 141.
Pfadt, R. E. and R. J. Lavigne. 1982. Food habits of grasshoppers inhabiting
the Pawnee site. Wyoming Agr. Exp. Stn. Sci. Monogr. 42.
Scoggan, A. C. and M. A. Brusven. 1972. Differentiation and ecology
of common immature Gompho-cerinae and Oedipodinae (Orthoptera: Acrididae)
of Idaho and adjacent areas. Melanderia 8: 1-76.
Tinkham, E. R. 1948. Faunistic and ecological studies on the Orthoptera
of the Big Bend Region of Trans-Pecos Texas with especial reference to
the Orthopteran zones and faunae of Midwestern North America. American
Midland Naturalist 40: 521-663.
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