Tetrix ceperoi

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Tetrix ceperoi
Tetrix ceperoi.jpg
Scientific classification OOjs UI icon edit-ltr.svg
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Orthoptera
Suborder: Caelifera
Family: Tetrigidae
Genus: Tetrix
Species:
T. ceperoi
Binomial name
Tetrix ceperoi
(Bolívar, 1887) [1]

Tetrix ceperoi, Cepero's groundhopper, [2] is a member of the family Tetrigidae and is very similar to common grasshoppers. [3] Grasshopper is defined as a "plant eating insect with long hind legs that are used for jumping and for producing a chirping sound". [4] However, unlike the common grasshopper, the wings of T. ceperoi extend beyond its pronotum (the upper surface of the first segment of the thorax). [5] [6] The front wings have evolved throughout history to be stumps, and the back wings are very well developed. [3] Thanks to the front wings only, T. ceperoi is capable of flying. [7] Furthermore, T. ceperoi sports wide shoulders while covering its narrow abdomen beneath the pronotum. [7] T. ceperoi are classified as Orthoptera, which describes crickets, grasshoppers, and locusts. Furthermore, these Orthoptera have incomplete metamorphosis, which also affects sexual dimorphism later. [8] T. ceperoi reach an average length of about 10 millimetres (0.39 in). [5] T. ceperoi is a multi-coloured ground dweller with the ability to blend into its surroundings. [9] [10] The ability of T. ceperoi to be different colours makes it able to evolve colour schemes better adapted to specific habitats. This cryptic nature of their outer layer provides protection from predators as it is able to blend into its surroundings. T. ceperoi is diurnal, which means it is solely active in the daytime. However, although it is diurnal, it continues to hibernate during a late nymphal instar or later on in life as adults. [11]

Contents

Habitat

T. ceperoi naturally resides in places with a hot climate, in damp and bare areas of land. [12] However, due to threatened natural habitats, T. ceperoi also makes a home in dunes along shore lines, and in low and open vegetations. [3] It exists across the coasts of the West Mediterranean area, Central Europe, Germany, Southern England and South Wales. [5] [9] [11] As T. ceperoi has evolved, it has also become capable of surviving in "floodplains, moist dune slacks, sand pits, drainage ditches or ponds". [13] Adult T. ceperoi are skilled swimmers and therefore are not hindered by the large amounts of water in close proximity. [7]

Conservation

T. ceperoi is becoming an endangered species in Central Europe due to "coastal protection and floodplain regulation". [14] Therefore, It can only claim its true natural habitat in areas of the Wadden Sea Islands. [12]

Habitat experiments

T. subulata interferes with reproduction in T. cepnoi. Tetrix subulata 3.JPG
T. subulata interferes with reproduction in T. cepnoi.

The question of the little-known habitat of T. ceperoi has come into greater study recently. Hochkirch et al. observed the reproductive interference between T. ceperoi and T. subulata, a neighbor and closely related species. Often two species that are very similar and share similar habitats are able to coexist, but do so at the cost of one species eventually being displaced by the interaction and experience lower fitness. Before one is displaced, the two species can go through intense competition. Two different ways animals can experience competition could be resource competition and reproductive competition. Resource competition could consist of fighting for food or territorial locations strategically safe from harm whether that be from predators or weather. Reproductive competition is the result of similar species exhibiting similar mating and courting systems. T. ceperoi shares some common territory with T. subulata because of common habitat requirements, however they do not "co-occur locally". [13] Experiments were conducted by based on the mechanisms of coexistence to better understand the interaction because previous "in lab" and "in the wild" experiments disagreed. [13] This study had four primary ways of attacking the question of how reproductive interference was handled. First, they studied wild ground hoppers in order to understand the magnitude and sexual interaction of species in the wild. Second, they analyzed if the species used different micro habitats, which was important because it could lead to "segregation on a micro-scale". Third, they mapped where and in what amounts each species was present in relation to food sources in order to see if there was any type of segregation or aggregation. Lastly, they experimentally changed the different habitats in order to see if the spatial distribution was a reflection of the "micro-habitat preferences". [13]

One theory of temporal segregation was able to be ruled out immediately based on the fact that both species are diurnal. [11] [13] If one had been nocturnal, while the other was diurnal, the temporal patterns of each species could be deemed the way reproductive interference was battled. Next, the species courting actions could be separated based on the movements of their body. T. ceperoi performed "pronotal bobbing", which is basically quick movement of the hind legs and the covering of the first thoracic segment. [13] T. subulata on the other hand must simply swing their body both laterally and frontally, spending less energy than T. ceperoi, to mate. [13] The study conducted in Emsland, Germany, was conducted between 10:30 and 17:00 on 116 individuals for thirty-minute increments. [13] Results showed that males, who are inclined to court anything that is about their size and moves, more often attempted to court females. [13] However, the females that were the receivers of the attention were not limited to the species of the male, indicating heterospecific interactions. [13] Furthermore from the female standpoint, T. ceperoi females fought off heterospecific interactions more than T. subulata, who performed defensive maneuvers equally towards heterospecific interactions as well as conspecific. [13] Microhabitat preference analysis results yielded T. subulata enjoyed taller vegetation areas with more ground cover than T. ceperoi. [13] This is important because Hochkirch et al. believe although resource and reproductive competition play a huge role in the interspecies interaction, the costs can be offset by different habitat factors such as segregative mechanisms, dilution effects, and life history effects. [13] In accordance with Wertheim et al., the results showed coexistence can be explained by intraspecific aggregations despite the presence or absence of unequally distributed resources. [13] [15]

Lastly, the group was able to determine the reason for difference between testing done in the lab versus testing done in the wild could most likely be accredited with the increased number of forced heterospecific interactions due to small arenas in the lab testing. [13] This conclusion further indicated that reproductive interference is density dependent, which was in accordance with previous studies. [13] [16] [17] [18]

Sexual dimorphism

T. ceperoi males are able to distinguish between similar species, but not between sexes, due to a rather large sexual dimorphism. [13] Sexual dimorphism is the different characteristics present in individuals of the same species, but opposite sexes. The sexual dimorphism between the two sexes is a result of a single additional instar in the female larval stages. [9] This indicates the male emerges sooner than the female and therefore can link the larger size to the additional period of growth.

T. ceperoi is not unique in its apparent sexual dimorphism, as many Orthoptera present the similar traits of females averaging 9% larger than males. [15] T. ceperoi is a member of the Caelifera suborder, in which sexual size dimorphism is about 37% strong and ranges from -20%-140% across the suborder. [15] One important fact to take note of is the females in this suborder are larger than males, while males conserve a comparable height across species, which is different from the Ensifera sexual dimorphism where females are comparable and male size decreases. [15] Sexual dimorphism causes resource competition as a result of "niche breadth and dispersion pattern". [13]

Sexual size dimorphism experiments

Hochkirch et al.

The dimorphism in the order could either be a result of intersexual competition or differential equilibrium. [19] Intersexual competition refers to the sexes feeding on different resources in order to reduce the competition within the species, while differential equilibrium refers to the different body sizes as a result of the opposing strategies of each sex to increase fitness. Females tend to lay more eggs and invest more time in those specific eggs directly opposing males who in order to increase their own fitness, spend less time on a specific group of eggs, and attempt to fertilise as many eggs as possible. The differential equilibrium hypothesis is well supported; however it cannot be deemed the clear answer because not enough experiments have tested intersexual competition. [19] One problem with comparing these two different hypotheses comes from the chance that dimorphic niches may have evolved from something in the past that is no longer present today, also known as "ghost of competition past" by Connell. [20] Information was collected from 3 main databases, which spanned 1503 species of Oriental and African Orthoptera, to determine females were larger in the majority of the 99.6% of the species. [19] Another hypothesis was that perhaps the temperature controlled the growth of Orthoptera, which would be in accordance with previous data that Omocestus viridulus had the additional instar stage in only low altitude areas of the Alps. [19] [21] The study concludes with numerous theories, but decides there is not sufficient research to determine the exact cause of sexual size dimorphism in Orthoptera. [19]

Krause et al.

The sexual dimorphism is believed to be a result of the different niches selected by each sex. [22] The choice between habitats for each sex has been hypothesised by Krause et al. to be a result of the reproductive costs and activities. [9] Krause et al. discovered males flock to brighter areas and are on bare ground (which is used during mating) more than females. [9] Females on the other hand "rest and feed on the vegetation". [9] These different places probably evolved due to the males who put themselves in danger of predation accruing greater chances at mating, while females enjoy nutrients to provide healthier offspring. [9]

Diet

The diet of T. ceperoi is composed of moss and various plants. [3] The common mosses eaten by T. ceperoi include Bryum argenteum , B. caespiticum , Ceratodon purpureus and Barbula sp. . [23] Less common diet choices include grasses, algae, and sometimes animal fragments and organic debris. [23]

Reproduction

Throughout May and June, Male insects of the Orthoptera order lure females to them using mating sounds, and then forcibly insert their sperm directly into the female’s abdomen. [11] However, another source notes that Tetrigidae do not have tympanums and are unable to stridulate, but still display courtship behaviours for the female. [24] Since T. ceperoi is both Orthoptera and Tetrigidae, it seems there is some discontinuity and more research must be done to clear up the discrepancy. The sperm packet inserted into the female constitutes about 60% of the males' body weight.[ citation needed ] Sperm packages are important because they are a nuptial gift given to the female in exchange for mating. Nuptial gifts are packages put together by the male in order to be able to mate with the female. The female has the choice to accept the sperm package and mate, or deny it and wait for a more suitable candidate. The sperm package might seem like an entirely selfless and generous gift of the male in order to mate, but in reality, the nutrients in the sperm package provide nutrition for the female and therefore benefit the male’s offspring which increases his fitness. Moreover, nuptial gifts fulfill the selfish nature of most animal behaviours.

Related Research Articles

<span class="mw-page-title-main">Sex</span> Trait that determines an individuals sexually reproductive function

Sex is the trait that determines whether a sexually reproducing organism produces male or female gametes. Male plants and animals produce small mobile gametes, while females produce larger, non-motile ones. Organisms that produce both types of gametes are called hermaphrodites. During sexual reproduction, male and female gametes fuse to form zygotes, which develop into offspring that inherit traits from each parent.

<span class="mw-page-title-main">Sexual dimorphism</span> Condition where males and females exhibit different characteristics

Sexual dimorphism is the condition where sexes of the same species exhibit different morphological characteristics, particularly characteristics not directly involved in reproduction. The condition occurs in most animals and some plants. Differences may include secondary sex characteristics, size, weight, color, markings, or behavioral or cognitive traits. Male–male reproductive competition has evolved a diverse array of sexually dimorphic traits. Aggressive utility traits such as "battle" teeth and blunt heads reinforced as battering rams are used as weapons in aggressive interactions between rivals. Passive displays such as ornamental feathering or song-calling have also evolved mainly through sexual selection. These differences may be subtle or exaggerated and may be subjected to sexual selection and natural selection. The opposite of dimorphism is monomorphism, when both biological sexes are phenotypically indistinguishable from each other.

<span class="mw-page-title-main">Sexual differentiation</span> Embryonic development of sex differences

Sexual differentiation is the process of development of the sex differences between males and females from an undifferentiated zygote. Sex determination is often distinct from sex differentiation; sex determination is the designation for the development stage towards either male or female, while sex differentiation is the pathway towards the development of the phenotype.

<span class="mw-page-title-main">Sperm competition</span> Reproductive process

Sperm competition is the competitive process between spermatozoa of two or more different males to fertilize the same egg during sexual reproduction. Competition can occur when females have multiple potential mating partners. Greater choice and variety of mates increases a female's chance to produce more viable offspring. However, multiple mates for a female means each individual male has decreased chances of producing offspring. Sperm competition is an evolutionary pressure on males, and has led to the development of adaptations to increase males' chance of reproductive success. Sperm competition results in a sexual conflict of interest between males and females. Males have evolved several defensive tactics including: mate-guarding, mating plugs, and releasing toxic seminal substances to reduce female re-mating tendencies to cope with sperm competition. Offensive tactics of sperm competition involve direct interference by one male on the reproductive success of another male, for instance by physically removing another male's sperm prior to mating with a female. For an example, see Gryllus bimaculatus.

<span class="mw-page-title-main">Anisogamy</span> Sexual reproduction involving a large, female gamete and a small, male gamete

Anisogamy is a form of sexual reproduction that involves the union or fusion of two gametes that differ in size and/or form. The smaller gamete is male, a sperm cell, whereas the larger gamete is female, typically an egg cell. Anisogamy is predominant among multicellular organisms. In both plants and animals gamete size difference is the fundamental difference between females and males.

Monogamous pairing in animals refers to the natural history of mating systems in which species pair bond to raise offspring. This is associated, usually implicitly, with sexual monogamy.

<span class="mw-page-title-main">Sexual conflict</span> Term in evolutionary biology

Sexual conflict or sexual antagonism occurs when the two sexes have conflicting optimal fitness strategies concerning reproduction, particularly over the mode and frequency of mating, potentially leading to an evolutionary arms race between males and females. In one example, males may benefit from multiple matings, while multiple matings may harm or endanger females, due to the anatomical differences of that species. Sexual conflict underlies the evolutionary distinction between male and female.

<span class="mw-page-title-main">Tetrigidae</span> Family of grasshoppers

Tetrigidae is an ancient family in the order Orthoptera, which also includes similar families such as crickets, grasshoppers, and their allies. Species within the Tetrigidae are variously called groundhoppers, pygmy grasshoppers, pygmy devils or "grouse locusts".

<span class="mw-page-title-main">Sexual cannibalism</span> Practice of animals eating their own mating partners

Sexual cannibalism is when an animal, usually the female, cannibalizes its mate prior to, during, or after copulation. It is a trait observed in many arachnid orders and several insect orders. Several hypotheses to explain this seemingly paradoxical behavior have been proposed. The adaptive foraging hypothesis, aggressive spillover hypothesis and mistaken identity hypothesis are among the proposed hypotheses to explain how sexual cannibalism evolved. This behavior is believed to have evolved as a manifestation of sexual conflict, occurring when the reproductive interests of males and females differ. In many species that exhibit sexual cannibalism, the female consumes the male upon detection. Females of cannibalistic species are generally hostile and unwilling to mate; thus many males of these species have developed adaptive behaviors to counteract female aggression.

Tetrix transsylvanica, the Transsylvanian wingless groundhopper, is a species of insect in the family Tetrigidae. It is found in Romania and Slovenia and may be extinct in Croatia.

<i>Hetaerina</i> Genus of damselflies

Hetaerina is a genus of damselflies in the family Calopterygidae. They are commonly known as Rubyspots because of the deep red wing bases of the males. The name is from Ancient Greek: ἑταίρα (hetaira), courtesan. H. rudis, the Guatemalan rubyspot, is considered vulnerable on the IUCN Red Data List.

<span class="mw-page-title-main">Sexual dimorphism in non-human primates</span>

Sexual dimorphism describes the morphological, physiological, and behavioral differences between males and females of the same species. Most primates are sexually dimorphic for different biological characteristics, such as body size, canine tooth size, craniofacial structure, skeletal dimensions, pelage color and markings, and vocalization. However, such sex differences are primarily limited to the anthropoid primates; most of the strepsirrhine primates and tarsiers are monomorphic.

<i>Idotea balthica</i> Species of crustacean

Idotea balthica is a species of marine isopod which lives on seaweed and seagrass in the subtidal zone of rocky shores and sandy lagoons.

<span class="mw-page-title-main">Sexual selection in birds</span>

Sexual selection in birds concerns how birds have evolved a variety of mating behaviors, with the peacock tail being perhaps the most famous example of sexual selection and the Fisherian runaway. Commonly occurring sexual dimorphisms such as size and color differences are energetically costly attributes that signal competitive breeding situations. Many types of avian sexual selection have been identified; intersexual selection, also known as female choice; and intrasexual competition, where individuals of the more abundant sex compete with each other for the privilege to mate. Sexually selected traits often evolve to become more pronounced in competitive breeding situations until the trait begins to limit the individual's fitness. Conflicts between an individual fitness and signaling adaptations ensure that sexually selected ornaments such as plumage coloration and courtship behavior are “honest” traits. Signals must be costly to ensure that only good-quality individuals can present these exaggerated sexual ornaments and behaviors.

<span class="mw-page-title-main">Sexual selection in amphibians</span> Choice of and competition for mates

Sexual selection in amphibians involves sexual selection processes in amphibians, including frogs, salamanders and newts. Prolonged breeders, the majority of frog species, have breeding seasons at regular intervals where male-male competition occurs with males arriving at the waters edge first in large number and producing a wide range of vocalizations, with variations in depth of calls the speed of calls and other complex behaviours to attract mates. The fittest males will have the deepest croaks and the best territories, with females making their mate choices at least partly based on the males depth of croaking. This has led to sexual dimorphism, with females being larger than males in 90% of species, males in 10% and males fighting for groups of females.

Sexual coercion among animals is the use of violence, threats, harassment, and other tactics to help them forcefully copulate. Such behavior has been compared to sexual assault, including rape, among humans.

<span class="mw-page-title-main">Polyandry in nature</span>

In behavioral ecology, polyandry is a class of mating system where one female mates with several males in a breeding season. Polyandry is often compared to the polygyny system based on the cost and benefits incurred by members of each sex. Polygyny is where one male mates with several females in a breeding season . A common example of polyandrous mating can be found in the field cricket of the invertebrate order Orthoptera. Polyandrous behavior is also prominent in many other insect species, including the red flour beetle and the species of spider Stegodyphus lineatus. Polyandry also occurs in some primates such as marmosets, mammal groups, the marsupial genus' Antechinus and bandicoots, around 1% of all bird species, such as jacanas and dunnocks, insects such as honeybees, and fish such as pipefish.

<i>Tetrix subulata</i> Species of grasshopper

Tetrix subulata is a species of groundhopper known as the slender ground-hopper, awl-shaped pygmy grasshopper and the slender grouse locust. It is found across the Palearctic: in North America, across much of Europe and Asia, from the British Isles east to Siberia, and to the southern parts of North Africa.

Reproductive interference is the interaction between individuals of different species during mate acquisition that leads to a reduction of fitness in one or more of the individuals involved. The interactions occur when individuals make mistakes or are unable to recognise their own species, labelled as ‘incomplete species recognition'. Reproductive interference has been found within a variety of taxa, including insects, mammals, birds, amphibians, marine organisms, and plants.

References

  1. ↑ "Tetrix ceperoi ceperoi (Bolívar & I. 1887) - Encyclopedia of Life".
  2. ↑ "Orthoptera Recording Scheme - Orthoptera". Archived from the original on 2011-07-16. Retrieved 2011-05-02.
  3. 1 2 3 4 "Seaonscreen | Marine encyclopedia". www.seaonscreen.org. Archived from the original on 2012-03-23.
  4. ↑ "WordNet Search - 3.1".
  5. 1 2 3 "Cepero's Groundhopper | Wild About Britain". Archived from the original on 2011-09-28. Retrieved 2011-05-02.
  6. ↑ "Pronotum, pronotal".
  7. 1 2 3 "Tetrix ceperoi (Bolivar, 1887). Cepero's Groundhopper". Orthoptera Recording Scheme. Biological Records Centre . Retrieved May 3, 2011.
  8. ↑ Koarek P., Holuša J. & Vidli_ka, ￠. 2005: Blattaria, Mantodea, Orthoptera & Dermaptera of the Czech and Slovak Republics. Illustrated key 3. Kabourek, Zlin, 349
  9. 1 2 3 4 5 6 7 Krause, S., A. Hochkirch, J. Groning, Intersexual niche segregation in Cepero’s Ground-hopper, Tetrix ceperoi. Evolutionary Ecology 21: 6, 727-738, doi : 10.1007/s10682-006-9147-3
  10. ↑ Paul J (1988) Colour and pattern variation in Tetrix ceperoi Bolívar (Orthoptera: Tetrigidae): An aid to identification. Entomol Gaz 39:133–139
  11. 1 2 3 4 Kleukers R, van Nieukerken E, Ode´ B, Willemse L, van Wingerden W (1997) De Sprinkhanen en Krekels van Nederland (Orthoptera). Nederlandse Fauna I. KNNV Uitgeverij and EISNederland, Leiden
  12. 1 2 EBSCOhost Connection
  13. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 Reproductive interference in two ground-hopper species: testing hypotheses of coexistence in the field. Julia Gröning, Niklas Lücke, Alexander Finger, Axel Hochkirch
  14. ↑ Ecological Research Volume 22, Number 5, 767–773, doi : 10.1007/s11284-006-0315-2 Habitat preferences of an endangered insect species, Cepero’s ground-hopper (Tetrix ceperoi) Julia Gröning, Sascha Krause and Axel Hochkirch
  15. 1 2 3 4 Wertheim, B. et al. 2000. Species diversity in a mycophagous insect community: the case of spatial aggregation vs resource partitioning. J. Anim. Ecol. 69:335-351.
  16. ↑ Kuno E. 1992. Competitive exclusion through reproductive interference. Res. Popul. Ecol. 34: 275_284.
  17. ↑ Westman, K. et al. 2002. Replacement of the native crayfishAstacus astacus by the introduced species Pacifastacus leniusculus in a small, enclosed Finnish lake: a 30-year study. Ecography 25: 53_73.
  18. ↑ Hettyey, A. and Pearman, B. 2003. Social environment and reproductive interference affect reproductive success in the frog Behav. Ecol. 14: 294_300.
  19. 1 2 3 4 5 Hochkirch, A. and Groning, J. Sexual Size dimorphism in Orthoptera. Journal of Orthoptera Research 2008, 17 (2): 189-196.
  20. ↑ Connell J.H. 1980. Diversity and the coevolution of competitors, or the ghost of competition past. Oikos 35: 131-138.
  21. ↑ Berner D., Blanckenhorn W.U. 2006. Grasshopper ontogeny in relation to time constraints: adaptive divergence and stasis. Journal of Animal Ecology 75: 130-139.
  22. ↑ Ingrisch S, Köhler G (1998) Die Heuschrecken Mitteleuropas. Westarp Wissenschaften, Magdeburg
  23. 1 2 SCRIPRA FACULTATIS RERUM NATURALIUM ENVIRONMENTAL CHANGES UNIVERSITATIS OSTRAVIENSIS, 186, 2008 AND BIOLOGICAL ASSESSMENT IV 348 Bryophagy in the groundhopper Tetrix ceperoi (Orthoptera: Tetrigidae): analysis of alimentary tract contents Petr KO_AREK, Šarka GRUCMANOVA, Zuzana FILIPCOVA, Lenk BRADOVA, Vit_zslav PLAŠEK & Jaroslav HOLUŠA
  24. ↑ Hochkirch A, Deppermann J, Gröning J (2006) Visual communication behavior of three pygmy grasshoppers (Orthoptera, Tetrigidae). J Insect Behav 19:559–571
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