Phanaeus vindex

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Phanaeus vindex
RainbowScarab.jpg
Rainbow Scarab Dung Beetle (male).jpg
males
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Coleoptera
Family: Scarabaeidae
Genus: Phanaeus
Species:
P. vindex
Binomial name
Phanaeus vindex
MacLeay, 1819

Phanaeus vindex, also known as a rainbow scarab (like other members in its genus [1] ), is a North American species of true dung beetle in the family Scarabaeidae. It is found in eastern and central United States (Florida and New England to Arizona and Wyoming) and northern Mexico. [2] [3] It is the most widespread species of Phanaeus in the United States and it has a wide habitat tolerance. [2] It may hybridize with the generally less common P. difformis . [4]

Description

P.  vindex adults are hard-bodied beetles which range from approximately 11-22 millimeters (0.4-0.9 inches) in length. They are relatively bulky and oblong. These beetles are sexually dimorphic; the males can be identified by their iridescent elytra and a large horn on their heads while females have slightly less vibrant shells and lack horns. Females also have different numbers of segments on their abdomen than males. Additionally, the ends of male abdomens raise above the elytra, however, in females, they do not. On top of this, the abdomen is distinctly colored in both sexes. Like most Phanaeus species, male rainbow scarabs can be observed in either a major morph with large horns and bodies, or a minor morph, with significantly reduced horn and body size. [5]

Food Resources

Because P. vindex is member of the Scarabaeinae sub-family, they are considered to be “true dung beetles” and feed exclusively on fecal excrement through all stages of their life cycle. While they do prefer to feed on dung from pasture animals, rainbow scarabs do sometimes feed on wild animal feces in more forestal areas. Research has shown that rainbow scarabs have certain preferences when selecting feces to feed on; they are most attracted to excrement that is considered “fragrant” or produced by organisms that have very diverse diets. [5] They tend to consume dung from omnivores such as pigs and cows and will sometimes select herbivore dung, but they are least attracted to dung produced by carnivorous animals. [6] P. vindex is afforded a very wide range of feces in their diet as a result of being able to occupy various habitats and soil types across seasons. Typically, however, these beetles do prefer clay soils, in contrast with other scarab beetles which may be more prevalent in sandy habitats. [5]

Larvae of all dung beetles have biting mouthparts to help consume the feces, but when dung beetles in the Scarabaeidae family reach their adult stage, they develop specialized mouthparts in addition to the biting portions. Some of these include mandibular and maxillary fine fringes which can filter liquid and semi-liquid portions of the dung while eating, and molars, which can finely grind down solid particles in dung suspensions. Dung beetles also typically create nests around and within their food sources, but this behavior varies across species. P. vindex and other Phanaeus beetles exhibit complex paracoprid nesting, meaning they tunnel in order to create nests below piles of dung and build complex tunnels by which they can communicate and exchange food with nearby beetles. To do this, adults bury a large amount of fecal excrement and make many brood balls where they can keep their young. P. vindex also exhibits protective behaviors by protecting these brood balls with a cement-like layer of dung around the surface. The young beetles in brood balls will then feed off the dung until they reach maturity and can forage for food on their own. [5] [7]

Parasites

Due to the nature of their food resources, P. vindex is often exposed to parasites that live within fecal matter. One of these common parasites are Physocephalus sexalatus, a nematode parasite. These parasites live within various animals and then are consumed by dung beetles. When consumed, the beetles start to consume approximately half as much dung as they did before. Individual infected beetles are less effective at interacting with their environments and also will end up moving less dung. They dig shorter tunnels and produce less offspring. [8]

Life history

As a dung beetle exhibiting paracoprid behavior, or tunneling, both sexes of adult P. vindex work to make the tunnel network in which they will store dung and create brood balls where young can be incubated. To do this, they burrow below the pile of dung they have established and create a chamber; in doing so, they naturally sift the soil around their dung pats, allowing for redistribution of nutrients and loose soil which they use to fill the tunnels so they can protect brood balls in the chamber. [5]

When making the pear-shaped brood balls, P. vindex females perform what looks like a “butting” motion in order to push dung away from where it was originally placed. This behavior attracts males, who will work with the female to make the dung into a ball and roll it into the chamber through the tunnel system they construct together. Once the brood ball is at the bottom of the tunnels, female oviposition occurs, in which she places an egg in the center of the dung ball; several brood balls can be formed in this way, after which all of them will be coated with soil to preserve their quality. Once all the eggs have been positioned in the chamber, the male and female pair construct a second tunnel which contains food for newly hatched beetles as well as those that remain below the soil in colder climates. [9]

Like all beetles, P. vindex undergoes a larval stage followed by pupation before they reach their adult stage. The larvae and both the molting processes happen within the brood ball; it is only when these beetles reach their adult stage that they emerge from the dung in which their parents housed them. The time it takes for these rainbow scarabs to complete these stages ranges between two to six months, with the entire lifespan of the beetle being less than a year. In colder areas, adults will remain in the tunnel networks below the frost line until temperatures increase, after which they will emerge. Because P. vindex have such a varied distribution, most of them undergo the overwintering process under soil. [5] [9]

Rainbow Scarab Dung Beetle - 51048837398.jpg

After adults emerge from the soil, they begin the search for a new mate, after which the tunneling process will begin anew. Research has shown that the contents of soil heavily dictate where P. vindex choose to locate their dung pats and tunnel networks, especially because the sandy soils that most other scarab beetles prefer cause larval desiccation in P. vindex. [5]

Mating

Studies have demonstrated that among all dung beetles, but especially P. vindex, feeding and reproductive behaviors have a very close relationship. Both sexes of rainbow scarabs need to consume dung regularly in order to become sexually mature, but females especially need to have this particular diet so they can oviposit. [10]

Among P. vindex, there is varying parental investment, with the females tending to invest more in their offspring than the males. However, it has been observed that females that exhibit higher parental investment through the entire breeding process will tend to choose males that are likely to invest more. During a breeding season, one male and one female will form a breeding pair and conduct all the processes necessary to produce brood balls, but female P. vindex are iteroparous, meaning they can undergo multiple reproductive events in a lifetime, and these can occur with multiple males. [10] Even during one mating season, females will be willing to mate with multiple males, so males need to fight to maintain exclusive access. Males and females will work together to create the tunnel networks and feeding galleries under the dung pats long before the female is sexually mature, and selection has shown to favor males that help in the paracoprid activities and food positioning throughout the tunnel networks. Males will typically fight off other rivals at or around the burrows they have helped create because they can better defend females and their eggs there. [10]

Development

Because P. vindex are able to inhabit such a wide range of habitats, research has been done to investigate whether their reproductive habits change according to environmental factors to maximize offspring growth and development, or whether they remain a consistent behavior across all members of the species. One such factor is temperature, which has been known to impact insect development. However, reproductive behavior plasticity based on temperature differences can impact earlier life stage development, so this has been an area of focus.

P. vindex has been observed altering its reproductive behavior based on temperature. Higher temperatures during development have shown to cause faster transitions between life cycle stages, smaller adult body sizes, and potentially, lower survival rates. Consequently,  when they are in warmer climates, females tend to produce more brood balls and bury them deeper to get the broods to cooler areas and have more surrounding soil to protect dung quality. This can come at a cost to brood ball size which, because they are made out of the dung from which offspring get sustenance, can affect offspring nutrition. While there can be some consequences to these behaviors, findings have shown that this plastic adult behavior is adaptive and it can actually buffer developing offspring from temperature changes, which could otherwise adversely impact fitness of adult rainbow scarabs. [11]

Although not all dung beetles experience fitness trade-offs by engaging in these adaptive reproductive behaviors, P. vindex does. The most observable of these trade-offs is that brood balls are smaller as nesting depth increases to a certain extent. Additionally, although deeper nesting can protect offspring from high temperatures, it can cost parents time and energy, which can affect other fitness traits. [7] [11] However, studies have shown that up to an optimal temperature, cold-blooded organisms can become more productive, potentially allowing them to dig through and transport dung more efficiently. [7] Consequently, it is possible that behavioral plasticity in response to varying temperatures can produce more offspring that have a greater chance of survival, even if the offspring do end up being smaller than their typical size. [11]

Related Research Articles

<span class="mw-page-title-main">Dung beetle</span> Informal group of insects

Dung beetles are beetles that feed on feces. Some species of dung beetles can bury dung 250 times their own mass in one night.

<span class="mw-page-title-main">Scarabaeinae</span> Subfamily of beetles

The scarab beetle subfamily Scarabaeinae consists of species collectively called true dung beetles. Most of the beetles of this subfamily feed exclusively on dung. However, some may feed on decomposing matter including carrion, decaying fruits and fungi. Dung beetles can be placed into three structural guilds based on their method of dung processing namely rollers (telecoprids), dwellers (endocoprids) and tunnelers (paracoprids). Dung removal and burial by dung beetles result in ecological benefits such as soil aeration and fertilization; improved nutrient cycling and uptake by plants, increase in Pasture quality, biological control of pest flies and intestinal parasites and secondary seed dispersal. Well-known members include the genera Scarabaeus and Sisyphus, and Phanaeus vindex.

<i>Nicrophorus quadripunctatus</i> Species of beetle

Nicrophorus quadripunctatus is a species of burying beetle that predominates in East Asia. First described by German entomologist Ernst Kraatz in 1877, this beetle has since been the subject of much scientific inquiry—particularly concerning its parental care. Like other burying beetles, N. quadripunctatus inhabit small, vertebrate animal carcasses. This environment provides the beetles with the requisite nutrients for themselves and their offspring. To limit resource theft and predation, the carcass is buried underground. For additional protection, a single, dominant male-female pair guards the carcass cooperatively.

<i>Scathophaga stercoraria</i> Species of fly

Scathophaga stercoraria, commonly known as the yellow dung fly or the golden dung fly, is one of the most familiar and abundant flies in many parts of the Northern Hemisphere. As its common name suggests, it is often found on the feces of large mammals, such as horses, cattle, sheep, deer, and wild boar, where it goes to breed. The distribution of S. stercoraria is likely influenced by human agriculture, especially in northern Europe and North America. The Scathophaga are integral in the animal kingdom due to their role in the natural decomposition of dung in fields. They are also very important in the scientific world due to their short life cycles and susceptibility to experimental manipulations; thus, they have contributed significant knowledge about animal behavior.

<i>Coccotrypes dactyliperda</i> Species of beetle

Coccotrypes dactyliperda, the date stone beetle, palm seed borer, or button beetle, is an insect belonging to the subfamily bark beetles (Scolytinae). It originates from Africa and is spread around the world due to the trading and transportation route.

Cephalodesmius is a genus of Scarabaeidae or scarab beetles.

<i>Coprophanaeus</i> Genus of beetles

Coprophanaeus is a genus in the family Scarabaeidae. The genus is almost entirely Neotropical, with a single species, C. pluto, ranging into southernmost Texas in the United States. They are medium-sized to large beetles, with the South American C. ensifer and C. lancifer sometimes exceeding 5 cm (2 in) in length, making these two some of the largest dung beetles in the world and the largest in the Americas. They often have a horn on the head, and are typically a bright metallic color, most often blue or green, or black. These diurnal or crepuscular beetles are excellent diggers and good fliers.

Filial cannibalism occurs when an adult individual of a species consumes all or part of the young of its own species or immediate offspring. Filial cannibalism occurs in many species ranging from mammals to insects, and is especially prevalent in various types of fish species with males that engage in egg guardianship. The exact evolutionary purpose of the practice in those species is unclear and debated among zoologists, though there is consensus that it may have, or may have had at some point in species' evolutionary history, certain evolutionary and ecological implications.

<i>Bolitotherus</i> Species of beetle

Bolitotherus cornutus is a North American species of darkling beetle known as the horned fungus beetle or forked fungus beetle. All of its life stages are associated with the fruiting bodies of a wood-decaying shelf fungus, commonly Ganoderma applanatum, Ganoderma tsugae, and Ganoderma lucidum.

<i>Onthophagus taurus</i> Species of beetle

Onthophagus taurus, the taurus scarab, is a species of dung beetle in the genus Onthophagus and the family Scarabaeidae. Also known as the bull-headed dung beetle, it is a species that specializes in cattle dung and is widely utilized to maintain clean pastures, making it agriculturally valuable. These beetles are typically 8–10 millimetres (0.31–0.39 in) in size. The males of this species exhibit distinct characteristics: large “major” males possess long, sweeping, curved horns resembling those of a longhorn bull, while small “minor” males have tiny horns that project upward from the back of their heads. Females, on the other hand, lack horns. These small beetles are oval shaped, the color is usually black or reddish brown. Sometimes the pronotum has a weak metallic sheen.

<i>Halictus ligatus</i> Species of bee

Halictus ligatus is a species of sweat bee from the family Halictidae, among the species that mine or burrow into the ground to create their nests. H. ligatus, like Lasioglossum zephyrus, is a primitively eusocial bee species, in which aggression is one of the most influential behaviors for establishing hierarchy within the colony, and H. ligatus exhibits both reproductive division of labor and overlapping generations.

<i>Sceliages</i> Subgenus of beetles

Sceliages, Westwood,, is a sub-genus of the Scarabaeus dung beetles, and are obligate predators of spirostreptid, spirobolid and julid millipedes, having renounced the coprophagy for which they were named. The genus is near-endemic to Southern Africa, Sceliages augias exceptionally ranging as far north as the Democratic Republic of Congo.

<i>Coprophanaeus ensifer</i> Species of beetle

Coprophanaeus ensifer is a large South American species of beetle belonging to the family Scarabaeidae. This species is necrophagous and builds burrows near or on animal carcasses to dismember the flesh of decaying bodies and bring it to its burrow to feed. Both females and males help build the burrow and feed. It is characterized by its iridescent colors and a horn that is similar in shape and size in females and males. It uses its horn to tear apart carcasses and to fight with other individuals, with male-male fighting occurring more often. However, females also fight to determine a variety of characteristics of the opposing male. This species may be of importance in forensic science due to its destructive behavior on decaying bodies, especially in areas of Brazil where homicide rates are high.

<i>Phanaeus</i> (beetle) Genus of beetles

Phanaeus, the rainbow scarabs, is a genus of true dung beetles in the family Scarabaeidae, ranging from the United States to northern Argentina, with the highest species richness in Mexico. Depending on species, they can inhabit a wide range of habitats, from tropical to temperate climates and deserts to rainforests. In those living in relatively arid places adults are primarily active during the wet season and those living in relatively cold places are primarily active during the summer. They are excellent diggers and good fliers.

<i>Sulcophanaeus imperator</i> Species of beetle

Sulcophanaeus imperator is a brightly colored species of dung beetle belonging to the family Scarabaeidae. This diurnal, coprophagous beetle is native to south-central South America and generally common. It is paracoprid, meaning that adults dig tunnels into the soil under the food source and move parts of the food source to a nest chamber where the eggs are laid.

<span class="mw-page-title-main">Phanaeini</span> Tribe of beetles

Phanaeini is a tribe of dung beetles in the family Scarabaeidae. There are about 12 genera and 200 described species in Phanaeini. They are native to the Americas with the highest species richness in the Neotropics. They are mostly coprophagous or necrophagous, but some of the least known genera appear to be myrmecophilous. They are medium-sized to large beetles, often with bright metallic colors, and often with horns on their heads.

<i>Euoniticellus intermedius</i> Species of beetle

Euoniticellus intermedius is a species of dung beetle in the family Scarabaeidae. E. intermedius is native to Southeastern Africa but has spread to the United States, Mexico, and Australia. E. intermedius acts as an important agricultural agent due to its improvement of soil quality and removal of parasitic pests.

<i>Coprophanaeus lancifer</i> Species of beetle

Coprophanaeus lancifer is a large species of beetle belonging to the family Scarabaeidae.

<span class="mw-page-title-main">White worm beetle</span> Species of beetle

The white worm beetle is a species of beetle in the family Scarabaeidae. It is the only species in the genus Hylamorpha. This beetle is native to South America, particularly in regions of Argentina, Brazil, and Uruguay.

<i>Thorectes lusitanicus</i> Species of beetle

Thorectes lusitanicus is a medium-sized dung beetle ranging from 30-175 mg in dry body weight. It is flightless with strong mandibles that allow it to exploit dry dung. It is native to the southern Iberian Peninsula. It is a tunneller that builds shallow tunnels several meters from the site of a dung deposition and transports the dung into the tunnel. Once the dung is in the tunnel, females of this species lay their eggs within it.

References

  1. ↑ "Genus Phanaeus - Rainbow Scarabs". BugGuide. Retrieved 27 June 2023.
  2. 1 2 "Species Phanaeus vindex - Rainbow Scarab". BugGuide. Retrieved 27 June 2023.
  3. ↑ Zídek, J.; Edmonds, W.D. (2012). "Taxonomy of Phanaeus revisited: Revised keys to and comments on species of the New World dung beetle genus Phanaeus MacLeay, 1819 (Coleoptera: Scarabaeidae: Scarabaeinae: Phanaeini)". Insecta Mundi. 2012 (274): 1–108. doi:10.5281/zenodo.5182095.
  4. ↑ "Phanaeus difformis Species Information". BugGuide.net. Iowa State University. Retrieved 2018-01-25.
  5. 1 2 3 4 5 6 7 Paris, Thomson; Rohde, Barukh; College, Hunter; Kaufman, Phillip. "Rainbow scarab - Phanaeus vindex Macleay". Featured Creatures. University of Florida Institute of Food and Agricultural Sciences. Retrieved 19 April 2022.
  6. ↑ Cartwright, O. L. (1968-03-15). "The Natural History of Dung Beetles of The Sub-Family Scarabaeinae (Coleoptera: Scarabaeidae)". Bulletin of the Entomological Society of America. 14 (1): 83. doi:10.1093/besa/14.1.83b. ISSN   0013-8754.
  7. 1 2 3 Cano, J. M.; Nicieza, A. G. (June 2006). "Temperature, metabolic rate, and constraints on locomotor performance in ectotherm vertebrates". Functional Ecology. 20 (3): 464–470. Bibcode:2006FuEco..20..464C. doi:10.1111/j.1365-2435.2006.01129.x. ISSN   0269-8463.
  8. ↑ Boze, B. G. V.; Moore, J. (2014-07-01). "The Effect of a Nematode Parasite on Feeding and Dung-Burying Behavior of an Ecosystem Engineer". Integrative and Comparative Biology. 54 (2): 177–183. doi:10.1093/icb/icu017. ISSN   1540-7063. PMID   24737785.
  9. 1 2 Halffter, Gonzalo; Halffter, Violeta; G., Irma Lopez (1974-04-01). "Phanaeus Behavior: 2 Food Transportation and Bisexual Cooperation1". Environmental Entomology. 3 (2): 341–345. doi:10.1093/ee/3.2.341. ISSN   1938-2936.
  10. 1 2 3 Price, Dana L.; May, Michael L. (2009-04-15). "Behavioral Ecology of Phanaeus Dung Beetles (Coleoptera: Scarabaeidae): Review and New Observations". ACTA Zoológica Mexicana. New Series. 25 (1). doi:10.21829/azm.2009.251621. ISSN   2448-8445.
  11. 1 2 3 Kirkpatrick, William H.; Sheldon, Kimberly S. (July 2022). "Experimental increases in temperature mean and variance alter reproductive behaviours in the dung beetle Phanaeus vindex". Biology Letters. 18 (7). doi:10.1098/rsbl.2022.0109. ISSN   1744-957X. PMC   9256084 . PMID   35857889.
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