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Field
Guide to Common Western Grasshoppers
by Robert
E. Pfadt
Introduction
| External Anatomy |
Names and Species | Grasshopper Populations
| Life Cycles | Seasonal
Occurrence and Behavior | Collections
and Survey | Grasslands of North America
| Food Plants | Glossary
| Selected References |
Species Fact Sheets | (PDF)
Glossary
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Abdomen. The hind region of the insect body consisting of
nine apparent ringlike flexible segments in the grasshopper (Fig.
1).
Accidentals. Adult grasshoppers in locations where the species
does not complete its life cycle.
Acrididae. A family of insects that comprise the grasshoppers
with short antennae, short ovipositor, and tarsi of legs three-segmented.
Aedeagus. The intromittent or insertion organ of the male
genitalia (Fig. 8).
Allotype. A paratype specimen of the opposite sex to the
holotype used in making the original description of a species.
Anal area of tegmen. Hind or posterior part of tegmen (Fig.
7).
Annulus. A colored or light circular band.
Antenna (pl., antennae). Pair of segmented appendages (feelers)
located on head and sensory in function (Fig.
1).
Anterior. Pertaining to the front of the body.
Apex. The terminal or distal part of a body structure.
Appetitive flight. Local movement by flight concerned with
finding food, mates, and egg laying sites.
Apterous. Without wings.
Arcuate. Arched or humped.
Arolium. A padlike structure at the end of the insect leg
between the claws (Fig.
6).
Arthropoda. A group or phylum of animals that have segmented
bodies, exoskeletons, and jointed legs.
Articulate. To connect by a joint.
Bandwinged grasshoppers. A subfamily of grasshoppers, the
Oedipodinae, that usually have a submarginal dark band on the hindwings
(Fig. 7).
Basal. At or near base of a structure.
Bilobate. Divided into two lobes.
Biotic potential. The inherent properties of an organism
to survive, reproduce, and increase in numbers.
Blastokinesis. Active movement of the grasshopper embryo
by which it passes from the ventral to the dorsal side of the egg
and at the same time revolves 180 degrees on its long axis.
Blowouts. A hollow of several acres formed by action of
wind.
Brachypterous. With short wings.
Brood. All the individuals that hatch at about one time
from eggs laid by one series of parents and that normally mature
at about the same time; a group of individuals of a species that
have hatched into young or have become adult at approximately the
same time, and live together in a defined and limited area, and
they may be of different generations.
Calcar. A spinelike process of the integument connected
by a joint (Fig. 6).
Carina (pl., carinae). An external ridge of the integument
(Fig. 4).
Carinula (pl., carinulae). A little carina or ridge (Fig.
6).
Center of distribution. The circumscribed area of habitats
in which the species is almost always present and where dense populations
regularly occur.
Cercus (pl, cerci). An appendage of the tenth abdominal
segment usually triangular and short in grasshoppers (Fig.
8).
Chevrons. A pattern of V-shaped markings in one direction
on the medial area of the grasshopper’s hind femur.
Chorionic sculpturing. A network pattern on the chorion
(shell) of the insect egg.
Clavate. Clubbed, having a thickened or expanded distal
end (Fig. 2).
Clypeus. The front liplike sclerite on which the labrum
articulates (Fig. 3).
Complete metamorphosis. Metamorphosis through which the
insect develops by four distinct stages: egg, larva, pupa, adult.
Compound eye. An eye made up of many individual eye elements
each represented externally by a corneal facet.
Concave. Hollowed out like the interior of a sphere segment.
Convex. Like the outer curved surface of a sphere segment.
Costal. Referring to the anterior portion of any wing (Fig.
7).
Coxa. Basal segment of insect leg articulating leg to body
(Fig 6).
Cristate. Having a prominent carina or crest.
Curate. To mount, label, store, and protect museum specimens.
Day-degrees. The degrees each day that the average daily
temperature is above a threshold temperature for development. For
each day that a process takes to complete, these degrees are totaled
to yield the day degrees required for the process such as egg incubation
or nymphal development.
Diapause. A state of low metabolic activity mediated hormonally
and associated with ceased growth, reduced activity, and increased
resistance to environmental extremes.
Disk of pronotum. Central upper surface of pronotum (Fig.
4).
Disk of wings. Central area of hindwings within the margins
or within the submarginal band when present (Fig.
7).
Distal. That part of an appendage farthest from the body.
Distribution. The location of all habitats in which the
species lives and reproduces; the area in which the species has
been recorded.
Distribution center. See center of distribution.
Dorsal. Pertaining to the top surface of the body.
Eclosion. The hatching of the larva or nymph from its egg.
Egg pod. A case made of grasshopper gluelike secretions
and soil particles enclosing a clutch of grasshopper eggs.
Emarginate. Notched.
Ensiform. Broad at base, narrowing to tip (Fig.
2).
Epiproct. A triangular dorsal plate of the eleventh abdominal
segment overlying the anus (Fig.
8).
Family. A taxonomic category including one genus or a group
of genera of common phylogenetic origin.
Fasciate. Banded.
Fastigium. The front part of the top of the head in front
of the compound eyes (Fig.
3).
Femoral stripe. The dark stripe running along the dorsal
medial area of the hind femur of a grasshopper.
Femur (pl., femora). A segment of the insect leg; the stout
segment of the grasshopper’s hindleg (Fig.
6).
Ferruginous. Resembling iron rust in color.
Filiform. Threadlike, slender and of equal diameter (Fig.
2).
Fledge. Acquisition of the adult wings.
Forb. Broadleafed herbaceous plant (e.g., dandelion).
Foveola (pl., foveolae). A small depression in the integument.
Frons. Front of the head above the clypeus (Fig.
3).
Frontal costa. Broad vertical ridge on the front of the
head (Fig. 3).
Furcula. Forked projection from posterior edge of tenth
abdominal tergum and overlying supraanal plate (Fig.
8).
Fuscous. Color of dark brown approaching black.
Griseous. Light color mottled with black or brown.
Gena. The sclerite at the side of the head (Fig.
3).
Gene. A unit of heredity on a chromosome in the cell nucleus.
Gene pool. The total genes of all the individuals of a species
in a population.
Genitalia. The external reproductive structures (Fig.
8).
Genus. A taxonomic category containing a group of related
species.
Geographic range. The area bounded by the location of outlying
populations of a species; the location of the smallest area within
an imaginary boundary line that encloses all populations of a species.
Gomphocerinae. A subfamily of grasshoppers known commonly
as slantfaced grasshoppers.
Gradual metamorphosis. Metamorphosis through which the insect
develops by three distinct stages, namely egg, nymph, adult.
Hindwings. The fanshaped membranous second pair of wings
of grasshoppers (Fig.
7).
Hirsute. Hairy.
Holotype. The single specimen designated as the "type"
by the author of the original description at time of publication.
Hyaline. Transparent and glassy.
Imago. A name for the adult insect.
Immaculate. Without spots or marks.
Incrassate. Thickened or swollen usually near tip.
Insecta. The insects; a class in the phylum Arthropoda in
which adults have three body regions, head, thorax, and abdomen;
three pairs of legs; and a respiratory system of air tubes or trachea.
Instar. The immature insect between two successive molts.
Invertebrate. Animal without spinal column or backbone.
Keel. A sharp, enlarged ridge or carina.
Key. A tabular arrangement of species, genera, families,
etc., according to characters that serve to identify them.
Knee. The enlarged end of the hind femur (Fig.
6).
Larva (pl., larvae). The immature insect hatched from the
egg and up to the pupal stage in orders with complete metamorphosis,
e.g., a caterpillar.
Lateral carinae. The carinae at the lateral edges of the
pronotal disk (Fig. 4)
or of the vertex of head (Fig.
3).
Lateral foveolae. A pair of small depressions on the head
at the side or front of vertex (Fig.
3).
Lateral lobe. The vertical sides of the pronotum (Fig.
4).
Maculate. Spotted.
Macropterous. With well developed long wings.
Medial. Situated in or closest to the middle.
Median area of tegmen. The middle part of tegmen (Fig.
7).
Median carina. Any ridge set medianly on an insect part,
such as the pronotum or head of a grasshopper (Fig.
4).
Melanoplinae. A subfamily of grasshoppers commonly known
as the spurthroated grasshoppers.
Mesosternal interspace. The area between the mesosternal
lobes (Fig. 5).
Mesosternal lobes. The paired separated posterior areas
of the mesosternum (Fig.
5).
Mesothorax. The middle segment of the thorax (Fig.
1).
Mesosternum. The ventral plate of the mesothorax between
and in front of the middle pair of legs (Fig.
5).
Metamorphosis. The change of body form through which insects
pass in developing to the adult.
Metasternal interspace. The area between the metasternal
lobes (Fig. 5).
Metasternal lobes. The paired separated posterior areas
of the metasternum (Fig.
5).
Metathorax. The hind segment of the thorax (Fig.
1).
Metazona. The posterior part of the pronotal disk, lies
behind the principal sulcus (Fig.
4).
Molt. Process of shedding outer layers of the integument.
Nodulate. A surface sculpturing of small knots or swellings.
Notum. The dorsal part or top of a thoracic segment (Fig.
1).
Nymph. An immature insect of species with gradual metamorphosis.
Occiput. Top of head behind the compound eye.
Ocellus (pl., ocelli). The single-faceted simple eye of
an insect. A grasshopper has three ocelli, two lateral and one median
(Fig. 3).
Outer margin of wing. The margin between apex and anal angle
of the grasshopper hindwing (Fig.
7).
Oedipodinae. A subfamily of grasshoppers known commonly
as bandwinged grasshoppers.
Orthoptera. An order of insects with gradual metamorphosis,
chewing mouthparts, and leathery forewings. Order includes grasshoppers
and crickets.
Ovipositor. In grasshoppers the paired digging and egg laying
structures at the end of the female abdomen (Fig.
1).
Ovipositor valves. Three pair of digging and egg laying
structures at the end of the abdomen in female grasshoppers (Fig.
1).
Pallium. The membrane stretching across the walls of the
subgenital plate and covering the male genitalia (Fig
8).
Paratype. A specimen other than the holotype that was before
the author at the time of preparation of the original description
and was so designated by the author.
Pellucid. Transparent whether clear or colored.
Preapical. Before the apex.
Pleuron (pl., pleura). The side sclerites of the thorax.
Posterior. Pertaining to the rear of the body.
Pottering. Intermittent walking and wandering with frequent
changes in direction.
Preoviposition period. The period between molting to the
adult and the laying of the first group of eggs; in grasshoppers
the period normally lasts one to two weeks.
Principal sulcus. The hind sulcus cutting the median carina
of the pronotum (Fig.
4).
Pronotum. The saddle-shaped top of the first thoracic segment
(Fig. 1).
Prosternal spine. A protuberant process of the prosternum
located between bases of front legs (Fig.
5).
Prosternum. The lower or ventral surface of the prothorax.
Prothorax. The front segment of the thorax (Fig.
1).
Proximal. That part of an appendage closest to the body.
Prozona. The anterior part of the pronotal disk, lies in
front of the principal sulcus (Fig.
4).
Pupa (pl., pupae). The stage between the larva and the adult
in insects with complete metamorphosis; a nonfeeding stage in which
adult structures develop and grow.
Quadrate. Resembling a square or rectangular space.
Ruderal. Growing along roadsides or in disturbed or abandoned
farmland.
Ruga (pl., rugae). A wrinkle.
Rugose. Wrinkled.
Sclerite. A hardened body wall plate of insects delimited
by sutures or membranous areas.
Seasonal cycle. The timing of the periods of egg hatch,
nymphal development, adulthood, and reproduction.
Shoulder. The lateral angles of the metazona of the pronotum
(Fig. 4).
Slantfaced grasshoppers. A subfamily of grasshoppers, the
Gomphocerinae.
Spatulate. Round and broadened apically, spoon-shaped.
Species. A kind of organism. A genetically distinctive group
of natural populations that share a common gene pool and are reproductively
isolated from all other such groups.
Spine. A thornlike outgrowth of the integument not separated
from it by a joint (Fig.
6).
Spur. A spinelike process of the integument connected by
a joint (Fig. 6).
Spurthroated grasshoppers. A subfamily of grasshoppers,
the Melanoplinae, that bear a conspicuous process (spine) on the
prosternum (Fig. 5).
Sternite. A subdivision of a sternum.
Sternum. The ventral part or bottom of a thoracic or abdominal
segment (Fig. 5).
Stadium (pl., stadia). The time period between two successive
molts of larvae or nymphs.
Stridulate. Making a creaking or grating sound by insects
through rubbing two rough surfaces against each other.
Stridulatory pegs. A row of small pegs on the inner surface
of the hind femur of certain grasshoppers (most slantfaced species)
(Fig. 6).
Styliform. Long and slender.
Sub-. Latin prefix meaning under; almost or somewhat.
Subarcuate. A little arched or bowed.
Subesophageal ganglion. Three fused ganglia located in head
below digestive tract innervating the mouthparts.
Subgenital plate. In the male grasshopper the terminal ventral
plate underlying the genitalia (Fig.
8).
Submarginal band. The dark band usually present on the hindwings
of species of bandwinged grasshoppers (Fig.
7).
Sulcus (pl., sulci). A groove or furrow in the integument.
Supraanal plate. A triangular dorsal plate of the eleventh
abdominal segment overlying the anus (Fig.
8).
Suture. A linelike groove in the integument.
Tarsus. The segmented foot of an insect; three segmented
in the grasshopper.
Tectate. Roof-like, sloping from a peak.
Tessellate. Mosaic or checkered.
Tegmen (pl., tegmina). The leathery, narrow, nearly parallel
sided forewings of grasshoppers and other Orthoptera (Fig.
7).
Tergum. The dorsal and lateral surface of an abdominal segment
(Fig. 8).
Testaceous. Brownish yellow.
Thorax. The middle body region of an insect between the
head and the abdomen (Fig.
1).
Threshold. The temperature or level of hormone concentration
that must be reached before development or growth can begin.
Tibia (pl., tibiae). The long, slender segment of the insect
leg (Fig. 6).
Tracheal system. The respiratory system of insects that
consists of internal airfilled tubes.
Trochanter. A small segment of the insect leg located between
the coxa and the femur (Fig.
6).
Truncate. Cut off squarely at end.
Tympanum. The membrane covering of the auditory organ.
Type. The single specimen that bears the name of the species
and from which the species was described.
Vagility. Capacity to disperse.
Valves of ovipositor. Three pair of digging and egg laying
structures at the end of the abdomen in female grasshoppers (Fig.
1).
Veins. The riblike tubes that strengthen the wings of insects.
Venation. The entire system of veins of an insect wing.
Ventral. Pertaining to the undersurface of the body.
Vertex. Top of head between the compound eyes.
Wing pads. The developing wings found on nymphs.
Wings. The hindwings of Orthoptera.
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Introduction
| External Anatomy |
Names and Species | Grasshopper Populations
| Life Cycles | Seasonal
Occurrence and Behavior | Collections
and Survey | Grasslands of North America
| Food Plants | Glossary
| Selected References |
Species Fact Sheets | (PDF)
|