Taeniopoda eques
Taeniopoda eques | |
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Adult female | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Arthropoda |
Class: | Insecta |
Order: | Orthoptera |
Suborder: | Caelifera |
Family: | Romaleidae |
Genus: | Taeniopoda |
Species: | T. eques
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Binomial name | |
Taeniopoda eques Burmeister, 1838
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Taeniopoda eques, the western horse lubber grasshopper, is a relatively large grasshopper species of the family
Etymology
T. eques was first described by Hermann Burmeister in 1838.[5] The vernacular lubber refers to the flightless terrestrial status of the subfamily Romaleinae.[4] Eques is the Latin term for "horseman".[6]
Distribution and habitat
T. eques is
Its main habitats are arid and semi-arid brush and grassland, but it may also occur in
Description
T. eques and
Males
Adults of both sexes have wings and in the male the forewings normally extend past the tip of the abdomen.[12] However, most T. eques cannot fly; all females are flightless and only approximately 10 percent of adult males possess wings long enough for flight.[13]
Diet
Taeniopoda eques does not feed on the same plants it roosts on. In an experiment, it was found to be unable to survive on
Life cycle
Taeniopoda eques is univoltine, producing only one brood of offspring per year. Females lay eggs at the base of shrubs or large rocks, depositing the approximately 50 eggs in a single pod 4-8 centimeters deep into the soil. The females also eject a liquid with the eggs, which dries and forms a hard case protecting the egg pod. In the United States, eggs are deposited in subterranean egg pods in October. The number of egg pods laid is dependent upon the rate of development in the adults and the time available before the frost sets in. The grasshoppers reach maturity in October and die in November during the winter freeze.[3] Thermoregulation is necessary for speeding the development of T. eques to increase its reproductive chances before the favorable growing season ends.[13]
Along with the onset of the summer rainy season, the young hatch in synchrony from subterranean egg pods in July. The larvae are especially vulnerable to predatory ants for about the first three minutes after hatching. After shedding the provisional cuticle, the larvae climb up the nearest vertical object. They are born reddish in color, but transform to black within two hours.[3]
Despite its large size, T. eques has a relatively speedy rate of larval development, undergoing five nymphal
Mating begins about 12 days after maturity, and about 30 days after the adults molt, females begin laying egg pods each containing about 50 eggs. Egg pods are deposited 6 to 9 centimeters underground. Females continue to lay subsequent egg pods at 18-day intervals until they are killed by the freeze in November.[3]
Behavior
Thermoregulation
Thermoregulation is necessary for all essential life functions of T. eques and most other behaviors, including food consumption and digestion, predator escape, reproduction, walking, flying, and ovipositing. The desert environment of T. eques is often unpredictable and allows the grasshopper only about four months, the time between the onset of the summer rains and the arrival of the winter freeze, to complete its entire life cycle. Growth and development are further slowed by cold desert nights, and in October, cold days. T. eques speed development by solar basking, aided by its black heat-absorbing coloration. By thermoregulating, the grasshopper can maintain an optimal body temperature between 30 and 40 degrees Celsius for most of the day. Elevating body temperature for extended periods allows T. eques to metabolize faster, thus permitting maximum growth and reproduction before the onset of winter.[13][15] Without thermoregulation, T. eques could not survive in its northern range.[13]
The unique black coloration of T. eques is thermally beneficial, contributing to the species' shorter larval development compared to the light- colored desert grasshoppers. T. eques has also developed behavioral thermoregulatory mechanisms for sunlight exposure. Flanking occurs when the grasshopper orients its body perpendicular to sunlight, maximizing thoracic heat gain. The sun-side hindleg is lowered, the shade-side hindleg is raised, and the abdomen is lowered to reduce wing shading. Moving into the centers of bushes allows for shading to limit sun exposure at midday to prevent overheating.[3][13]
Defense
Ants regularly attack hatching and molting nymphs. Vertebrates sharing the habitat of T. eques rarely disturb horse lubbers and prefer other lubber grasshopper species instead. Only invertebrates and
T. eques possesses a multi-sensory defense system. The chemical secretion has a strong coffee-vanilla odor and composed of a complex mixture of synthesized
Social behavior
In the first stage of life, pod mates aggregate and move and feed together, but disperse after a few days. Aggregation is tightest in this first-
Sexual behavior and pheromones
Both sexes of mature T. eques engage in promiscuous behavior. Males are sexually aggressive, actively mounting females and males of the species as well as individuals from other grasshopper and lizard species.[3]
Males cautiously stalk females before suddenly mounting without any communicatory leg or wing signaling. Females react violently when mounted by jumping, kicking, running, and rotating from side to side.[17] However, immediately following copulation, females become docile and carry males on their backs. Males do not guard ovipositing females.[3]
The female T. eques releases a pheromone that elicits male attraction and sexual behavior over a short distance. Male T. eques can remain in copulation for up to 24 hours, continuously passing spermatophores to the female.[17][18]
Trait interaction
Multiple phenotypic traits interact in T. eques since chemical defense from vertebrates releases the species from the need to be small and hidden. Thus T. eques has evolved a large body size, to increase fecundity, deter small invertebrate predators, increase water retention, and allow for deep ovipositing. However, the large adult size requires long development and growth, which is difficult in its short season. It speeds growth by thermoregulation mechanisms including dark color and solar exposure positions, both allowed only because of chemical defense. These features cause T. eques to be conspicuous; however, chemical deterrents protect it against predators. The species can allocate resources to reproduction instead of wings and flight muscles. As with many other chemically defended insects, T. eques is mostly flightless and sluggish.[13][16]
References
- ^ a b c d Hebard, M. (1925). "The group Taeniopodae as found in the United States (Orthoptera)". Transactions of the American Entomological Society. 51 (1): 1–12.
- ^ a b c d e Jesús-Bonilla, V.S.D.; Barrientos-Lozano, L.; Zaldívar-Riverón, A (2023). "Taxonomic revision of the transitional Nearctic-Neotropical lubber grasshopper genus Romalea (Orthoptera: Romaleidae)". Rev. Mex. Biodiv. 94.
- ^ .
- ^ ISBN 9780520078499. Retrieved 2011-04-27.
Latin American Insects and Entomology hogue.
- ISBN 0-9640101-5-1. Retrieved 2011-04-28.
- ^ Encyclopædia Britannica (2011). "Eques". World Wide Web electronic publication. Encyclopædia Britannica Online. Retrieved 2011-04-28.
- ^ a b c "Species Taeniopoda eques - Horse Lubber". bugguide.net. Retrieved 11 August 2023.
- ^ OL 16341758M.
- ^ a b c "Chapulines de Importancia Económica en México" (PDF). Dirección General de Sanidad Vegetal Dirección del Cento National de Referencia Fitosanitaria, Government of Mexico. Retrieved 11 August 2023.
- ^ .
- ^ Hebard, M. (1924). "A Revision of the Genus Taeniopoda (Orthoptera, Acrididae, Cyrtacanthacrinae)". Transactions of the American Entomological Society. 50 (4): 253–274.
- ^ ISBN 0-8014-8948-2. Retrieved 2011-04-28.
- ^ JSTOR 4911.
- S2CID 85309532.
- ^ Hamilton, W.J. (1975). Hadley, N.F. (ed.). "Coloration and its thermal consequences for diurnal desert insects". Environmental Physiology of Desert Organisms. Stroudsburg, PA: Dowden, Hutchinson & Ross: 67–89.
- ^ S2CID 85159286.
- ^ S2CID 85324838.
- S2CID 51703308.