Gryllus veletis
Encyclopedia
Gryllus veletis, commonly known as the spring field cricket, is abundant throughout eastern North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

. G. veletis is a solitary, aggressive, omnivorous, burrow-inhabiting species of field cricket
Field cricket
Field crickets are insects of order Orthoptera. These crickets are in subfamily Gryllinae of family Gryllidae.They hatch in spring, and the young crickets eat and grow rapidly. They shed their skin eight or more times before they become adults.Field crickets eat a broad range of feeds: seeds,...

. This species is commonly confused with Gryllus pennsylvanicus
Gryllus pennsylvanicus
Gryllus pennsylvanicus is one of many cricket species known as the field cricket. It occurs throughout eastern North America, including southern Canada.-Identification:...

(fall field cricket), as they inhabit the same geographical area. However, the two species are easily distinguished through examination of life history, ovipositor
Ovipositor
The ovipositor is an organ used by some animals for oviposition, i.e., the laying of eggs. It consists of a maximum of three pairs of appendages formed to transmit the egg, to prepare a place for it, and to place it properly...

 and behavioural differences. Predators of G. veletis, and most field crickets, include: American toad
American toad
The American Toad is a common species of toad found throughout the eastern United States and Canada. It is divided into three subspecies—the Eastern American Toad , the Dwarf American Toad , and the rare Hudson Bay Toad...

s, wild turkey
Wild Turkey
The Wild Turkey is native to North America and is the heaviest member of the Galliformes. It is the same species as the domestic turkey, which derives from the South Mexican subspecies of wild turkey .Adult wild turkeys have long reddish-yellow to grayish-green...

s, red-tailed hawk
Red-tailed Hawk
The Red-tailed Hawk is a bird of prey, one of three species colloquially known in the United States as the "chickenhawk," though it rarely preys on standard sized chickens. It breeds throughout most of North America, from western Alaska and northern Canada to as far south as Panama and the West...

s, wolf spider
Wolf spider
Wolf spiders are members of the family Lycosidae, from the Ancient Greek word "" meaning "wolf". They are robust and agile hunters with good eyesight. They live mostly solitary lives and hunt alone. Some are opportunistic hunters pouncing upon prey as they find it or even chasing it over short...

s and the red back salamander
Red Back Salamander
The red back salamander is a small, hardy woodland salamander. It inhabits wooded slopes in Eastern North America; west to Missouri; south to North Carolina; and north from southern Quebec and the Maritime Provinces in Canada to Minnesota...

.

Identification

Adult body length measures approximately 22.0 mm (0.87 inches). Males of this species are black with dark brown or black appendage
Appendage
In invertebrate biology, an appendage is an external body part, or natural prolongation, that protrudes from an organism's body . It is a general term that covers any of the homologous body parts that may extend from a body segment...

s. Females are similar in colour and have a dark brown ovipositor, measuring approximately 14 mm (0.55 inches). Female colouration differs from males as they have lighter, more reddish legs.

All species of field crickets generally look similar, with minor distinctions in morphological characteristics (i.e. coloration, ovipositor length, etc.) aiding in species identification. However, the male cricket's song play an important role in species identification. For an individual cricket, the species specific song helps distinguish mates and conspecifics from other species of crickets that might reside in the area. A recording of the spring field cricket's song can be heard here.

Distribution

Gryllus veletis is abundant throughout eastern North America. It ranges from southern Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...

 to northern Georgia
Georgia (U.S. state)
Georgia is a state located in the southeastern United States. It was established in 1732, the last of the original Thirteen Colonies. The state is named after King George II of Great Britain. Georgia was the fourth state to ratify the United States Constitution, on January 2, 1788...

, and as far west as Washington and Oregon
Oregon
Oregon is a state in the Pacific Northwest region of the United States. It is located on the Pacific coast, with Washington to the north, California to the south, Nevada on the southeast and Idaho to the east. The Columbia and Snake rivers delineate much of Oregon's northern and eastern...

 G. veletis occurs in the same areas as G. pennsylvanicus but the spring field cricket does not reach as far north as Nova Scotia
Nova Scotia
Nova Scotia is one of Canada's three Maritime provinces and is the most populous province in Atlantic Canada. The name of the province is Latin for "New Scotland," but "Nova Scotia" is the recognized, English-language name of the province. The provincial capital is Halifax. Nova Scotia is the...

, Canada. G. veletis can be found in disturbed habitats such as old fields, and weedy roadsides.

Life cycle and mating behaviour

Spring field crickets are sexually mature from late May to early August. Males of the species attract sexually receptive females by acoustic signals, known as stridulation
Stridulation
Stridulation is the act of producing sound by rubbing together certain body parts. This behavior is mostly associated with insects, but other animals are known to do this as well, such as a number of species of fishes, snakes and spiders...

. This process occurs by rubbing two rigid veins on the wings against one another. One vein is a scraper (smooth surface), the other a file (rough surface). The wings are held at a 45 degree angle above the thorax
Thorax
The thorax is a division of an animal's body that lies between the head and the abdomen.-In tetrapods:...

 to amplify the sound.
Calling tends to peak at sunrise and lasts between 1.3 to 1.8 hours per night. However, if nighttime temperatures drop below 10 °C (50 °F), calling will switch to the daytime. At 29 °C (85 °F), the cricket will call at 120–370 chirps per minute, in a series of 3 to 5-pulse chirps. When a female is within the vicinity of a male’s territory
Territory (animal)
In ethology the term territory refers to any sociographical area that an animal of a particular species consistently defends against conspecifics...

, a quieter song (known as a courtship song) is used to reduce the risk of predation
Predation
In ecology, predation describes a biological interaction where a predator feeds on its prey . Predators may or may not kill their prey prior to feeding on them, but the act of predation always results in the death of its prey and the eventual absorption of the prey's tissue through consumption...

 and attraction of male competitors. Both males and females have directional hearing. Tympanum
Tympanal organ
A tympanal organ is a hearing organ in insects, consisting of a membrane stretched across a frame backed by an air sac and associated sensory neurons...

s on the front legs pick up the vibrations created by the chirps. Depending on the strength, and on which leg the vibration is received, the location of the caller can be determined.

Once mating occurs, females use their ovipositor
Ovipositor
The ovipositor is an organ used by some animals for oviposition, i.e., the laying of eggs. It consists of a maximum of three pairs of appendages formed to transmit the egg, to prepare a place for it, and to place it properly...

 to lay eggs into a soil substrate. The eggs will mature between June and September. The immature spring field cricket will continue to develop into a late-instar
Instar
An instar is a developmental stage of arthropods, such as insects, between each molt , until sexual maturity is reached. Arthropods must shed the exoskeleton in order to grow or assume a new form. Differences between instars can often be seen in altered body proportions, colors, patterns, or...

 nymph
Nymph (biology)
In biology, a nymph is the immature form of some invertebrates, particularly insects, which undergoes gradual metamorphosis before reaching its adult stage. Unlike a typical larva, a nymph's overall form already resembles that of the adult. In addition, while a nymph moults it never enters a...

 and overwinter
Overwinter
To overwinter is to pass through or wait out the winter season, or to pass through that period of the year when “winter” conditions make normal activity or even survival difficult or near impossible...

 in this stage until emergence as adults in late May. G. veletis therefore undergoes one generation per year.

Human Impact

Spring field crickets are often grouped with the other species of field crickets when discussing their possible impacts on humans.

Field crickets, including G.veletis, are generally omnivorous scavengers. Their diet normally consists of plants, both fresh and decaying, other dead insects and in some cases predation of other field crickets or live insects may occur. An example of field cricket predation is seen in the consumption of fly pupae, which helps reduce the population of flies
Fließ
Fließ is a municipality in the Landeck district and is located5 km south of Landeck on the upper course of the Inn River. It has 9 hamlets and was already populated at the roman age; the village itself was founded around the 6th century. After a conflagration in 1933 Fließ was restored more...

, often viewed as pests by humans. Consumption of plant matter helps ensure that fallen leaves and other material does not accumulate. Along with other scavenger insects (i.e. earthworm
Earthworm
Earthworm is the common name for the largest members of Oligochaeta in the phylum Annelida. In classical systems they were placed in the order Opisthopora, on the basis of the male pores opening posterior to the female pores, even though the internal male segments are anterior to the female...

, beetles, etc.) decomposition of plants into fertile soil helps maintain a balanced ecosystem in forests and fields.

Unlike house crickets (Acheta domesticus), field crickets are not able to adapt to a residential environment due to constraints in their life history traits and consequently, the insect will not live through the winter.Though field crickets are not normally found in home environments, they may invade a home to seek refuge from poor weather, attraction to light, or in search of foodstuffs (i.e. grains, seeds, etc.). Entrance can be gained through small cracks and crevices leading into a building. Once inside, damage to nylon, wool, plastic and leather fabrics may occur. The field cricket does not consume these materials, but "cuts out" a path through which it may pass. The human inhabitant may be aggravated by the field cricket's nocturnal chirping.

External links

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