Bolitotherus

Last updated

Bolitotherus
Bolitotherus cornutus horned fungus beetle.jpg
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Coleoptera
Family: Tenebrionidae
Genus: Bolitotherus
Species:
B. cornutus
Binomial name
Bolitotherus cornutus
Panzer, 1794

Bolitotherus cornutus is a North American species of darkling beetle known as the horned fungus beetle [1] or forked fungus beetle. [2] All of its life stages are associated with the fruiting bodies of a wood-decaying shelf fungus, commonly Ganoderma applanatum , [2] Ganoderma tsugae , [2] and Ganoderma lucidum . [3]

Contents

Description

Adults are brown, armored beetles, 10–12 mm (0.4–0.5 in) long. [1] They are sexually dimorphic; males have two sets of horns and females lack horns. [4] Males use their horns, clypeal and thoracic, to compete for mates. Unlike many species of scarab beetles that exhibit male dimorphism for horns with major and minor morphs, [5] [6] [7] male B. cornutus possess a continuous range of horn and body sizes. [8] [9] Adult horned fungus beetles are active at night, but may be found during the day on the undersides of their host fungi.

Flight

The forked fungus beetle has the ability to fly; however, they are not at all reliant on flight. [10] The beetle itself is designed to be camouflaged onto bark or fungus, and so there is no advantage to frequent flights.

Habitat

The forked fungus beetle lives in a variety of climates. Due to the fact that the beetle consumes mainly shelf fungus of the Ganoderma family, they are restricted to areas in which Ganoderma fungus lives within North America. [11]

The beetle itself can live throughout these climates because they hibernate, or winter. Beetles of all developmental stages can winter but they tend to winter in different locations. Mature beetles can winter in bark, decaying trees, and stumps, among others. Both mature and immature beetles can also winter in fungus. [12]

Geographic range

Bolitherus cornutus tends to live in eastern North America. They do not have a strict climate preference, as they commonly live as north as Canada and as south as Florida. [5] The main requirement for where they will live correlates to where their preferred host fungus lives, and in turn the trees where the host fungus prefers to live.

Male territorial defense

The horned fungus beetle's entire life revolves around fungal brackets. Similarly to how a burying beetle needs a carcass to reproduce, horned fungus beetles need a fungal bracket to reproduce. Male beetles will find and defend a piece of fungus they deem to be good for offspring. Females are limited in how many offspring they can have by how big the fungus is, causing them to select males with larger pieces of fungi. This leads to male-male fighting over fungal brackets, as a male wants the largest fungus in order to attract females. [13]

Diet

The forked fungus beetle almost exclusively consumes the fungus of the Ganoderma family. Although adults can consume other materials, larvae prefer to only consume the egg that they hatched from and the fungus that they are raised within. [12]

Reproductive behavior

Oviposition

Unlike many darkling beetles, they tend to lay fewer eggs at a time, often only laying one egg per mate or even one egg per mating season. Their mating season usually lasts from June to August. The beetles very rarely lay more than one egg at a time, but on average can lay 8-12 eggs in a season. Eggs are only laid between June and August, which leads to a very limited number of offspring depending on how often females mate. [12]

Forked fungus beetle eggs are often laid in clutches of only one, but they can be laid in groups of egg capsules. These capsules are usually ovular in shape. They are usually 3.8 mm wide and 2.7 mm in width. The individual eggs within the capsule are translucent, approximately 2 mm long and 1mm wide. The eggs are white with raised darker spots. [12]

The eggs themselves can take anywhere between one and four weeks to hatch, but usually only take two. Post-hatching, the larvae take 5 days before they leave their egg capsules and go into the fungus they were laid upon. [12]

Mating

Bolitotherus cornutus adults perform reproductive behaviors on the surfaces of fruiting bodies of their host fungus. [8] Mating pairs engage in a courtship ritual in which the male grips the female's elytra, with his thorax over the end of her abdomen. Courtship often lasts several hours, and is a necessary precursor to copulation. During a copulation attempt, the male reverses position on top of the female so that both individuals point the same direction and their abdomens are aligned. If the courtship is successful, the female opens her anal sternite and copulation takes place. Following copulation, the male remains on top, facing the same direction as the female and mate-guards her. The male remains in this position for several hours, preventing other males from courting the female. Later, the female will deposit single eggs on the upper surface of a host fungus, then cover each egg with a distinctive dark brown oval of frass. When the eggs hatch, the larvae burrow into and consume the fungus, in which they later pupate before emerging as adults. [2]

Mate searching behavior

For B. cornutus, males need to attract females. Females have the ability to selectively open and close their anal plate in order to entirely physically block males. This means that many males need to present themselves for female selection. Males can convince females to mate with them by having territorial control over large fungal brackets. Females need as much food as possible for their offspring, and so females are more likely to be attracted to males who have a larger fungus. [10]

Male age based competition

Age has a major effect on the sperm for the forked fungus beetle.  As a male beetle ages, his sperm packet gets larger each time. It is not directly linked to each individual sperm packet being larger, but over time there is significant data. These larger sperm packets over time mean that older beetles are more likely to father offspring. This advantage specifically means that beetles that live the longest have the best chances of mating. [11]

Sexual selection

Horn length in male Bolitotherus cornutus is under significant direct selection. Females consistently select for longer horn lengths in male mates when given the opportunity. This positive selection on male horn length is mainly due to differences in the lifespan of male B. cornutus as well as concentration and access to females. Additionally, B. cornutus with longer horns on average also have longer elytral length, which are the hardened forewings of a beetle as well as bigger overall masses. As a result, all three of these traits result in positive total sexual selection amongst mating B. cornutus. [8]

Social behavior

Larval sociality and cannibalism

Larva often do not interact with their parents after hatching. Larva themselves are protected firstly by their egg capsules and then by the fungus they live and develop within when they hatch. Larva do not often interact with other larva, although larval passages and tunnels throughout the fungus often intersect. [12]

The pupal stage occurs after the larval stage. After create larval passages in the fungus, the larval will construct a pupal chamber in which it will mature. The larva will become less active as it becomes a pupa as it needs to enter this stage to mature into an adult beetle. This pupa is more prone to potential predators. Oftentimes, these pupa are attacked or consumed by larval siblings or by other forked fungus beetle larva. There is evidence of the larva potentially attacking and consuming one another, however, larval cannibalism of pupa has been experimentally observed. [12]

Once the pupa has matured into an adult beetle, the socialization between individuals of this species diminishes until reproduction. [12]

Life cycle

Forked fungus beetles are divided into two different brood groups for development. It is affected by when in the year the eggs are laid. [12]

For the first brood, the eggs are laid in June. They take approximately 2 weeks to hatch. Their larval stage can also take approximately 2 weeks. Then, their pupal stage can take approximately two months as they enter winter. The first brood spends their first winter as adults. [12]

For the secondary brood, eggs are laid in July and take longer on average to hatch than the first brood. Because of how late in the season the second brood hatches, they oftentimes winter in their larval stage. This means that they hibernate and slow their development during this time. They continue development again in the summer. Once they are done wintering, their pupal stage is shorter than the first brood's. Development for the forked fungus beetle is the quickest during early summer. The secondary brood becomes adults in their second summer and oftentimes can then reproduce within the same summer. [12]

Regardless of brood, the earliest they can reproduce is their second summer. However, the first brood tends to reproduce in the early summer and their offspring are more likely to be first brood. The second brood are usually not sexually mature until the end of their second summer, and so they are more likely to have second brood offspring. [12]

Forked fungus beetles can live up to 8 years, and so the pattern of first brood parents having first brood offspring, and second brood offspring have second brood offspring is unconfirmed and unstudied past their first reproductive season. [12]

Predators

B. cornutus has many predators. The majority of the fungus beetle's defenses are designed to fight against other members of the same species for reproductive purposes.

Mammalian

Due to the stationary nature of their life, it is also incredibly common for mammals to both purposefully and accidentally try to consume them. Rodents often predate on the beetle, ranging from small pocket mice to even large ground squirrels. [14]

Insect

The Eubadizon orchesiae , a braconid wasp, is a parasitic wasp that persists off of the eggs of the forked fungus beetle. [12] Female braconid wasps often find early-stage egg capsules of the forked fungus beetle and burrow a small hole within it in order to lay their eggs inside. They make a light yellow silken cocoon in the body of the larva. [2] However, they would also lay eggs within cracks and crevices of the fungal shelves the eggs were on as well. The wasps have a shorter gestation period than the forked fungus beetle, and so the larva of the braconid wasp will often consume the unhatched eggs or the larva of the forked fungus beetle. However, adult female braconid wasps themselves will often attack larva of the forked fungus beetle. [12]

Fungal

Some larvae die after attack by an uncharacterized parasitic fungus. Fomes applanatus is a fungus that often overtakes the fungal shelves that the forked fungus beetles lay their eggs upon. [12] The fungus itself will consume egg capsules as well as larva of the forked fungus beetle.

Defenses

The fungus beetle has three major defenses against these predators. The fungus beetle itself is camouflaged to fit into the fungus that it lives in. The rough texture and dark color often help the beetle blend into both the bark of the trees the fungus attached to as well as the fungus itself. Furthermore, the beetle's exoskeleton is quite hard and makes it difficult to puncture and attack the beetle. The most complex form of defense the beetle has is a chemical defense. B. Cornutus has the ability to detect mammalian breathe, and in response they can produce a volatile gas. This volatile gas can be produced by any mature forked fungus beetle, but their diet can affect the exact makeup of the gas. [11]

Related Research Articles

<span class="mw-page-title-main">Evergreen bagworm</span> Species of moth

The evergreen bagworm, commonly known as bagworm, eastern bagworm, common bagworm, common basket worm, or North American bagworm, is a moth that spins its cocoon in its larval life, decorating it with bits of plant material from the trees on which it feeds.

<i>Manduca sexta</i> Species of moth

Manduca sexta is a moth of the family Sphingidae present through much of the Americas. The species was first described by Carl Linnaeus in his 1763 Centuria Insectorum.

Holometabolism, also called complete metamorphosis, is a form of insect development which includes four life stages: egg, larva, pupa, and imago. Holometabolism is a synapomorphic trait of all insects in the superorder Holometabola. Immature stages of holometabolous insects are very different from the mature stage. In some species the holometabolous life cycle prevents larvae from competing with adults because they inhabit different ecological niches. The morphology and behavior of each stage are adapted for different activities. For example, larval traits maximize feeding, growth, and development, while adult traits enable dispersal, mating, and egg laying. Some species of holometabolous insects protect and feed their offspring. Other insect developmental strategies include ametabolism and hemimetabolism.

<i>Phanaeus vindex</i> Species of beetle

Phanaeus vindex, also known as a rainbow scarab, is a North American species of true dung beetle in the family Scarabaeidae. It is found in eastern and central United States and northern Mexico. It is the most widespread species of Phanaeus in the United States and it has a wide habitat tolerance. It may hybridize with the generally less common P. difformis.

<i>Osmia lignaria</i> Species of bee

Osmia lignaria, commonly known as the orchard mason bee or blue orchard bee, is a megachilid bee that makes nests in natural holes and reeds, creating individual cells for its brood that are separated by mud dividers. Unlike carpenter bees, it cannot drill holes in wood. O. lignaria is a common species used for early spring fruit bloom in the United States and Canada, though a number of other Osmia species are cultured for use in pollination.

<i>Papilio demodocus</i> Species of butterfly

Papilio demodocus, the citrus swallowtail or Christmas butterfly, is a swallowtail butterfly which commonly occurs over the entirety of sub-Saharan Africa, including Madagascar, besides the southern Arabian Peninsula. The caterpillars feed on various native plants of especially the family Rutaceae, but have also taken to the leaves of cultivated citrus trees.

<i>Cotinis nitida</i> Species of beetle

Cotinis nitida, commonly known as the green June beetle, June bug or June beetle, is a beetle of the family Scarabaeidae. It is found in the eastern United States and Canada, where it is most abundant in the South. It is sometimes confused with the related southwestern species figeater beetle Cotinis mutabilis, which is less destructive.

<i>Lasioderma serricorne</i> Species of beetle

Lasioderma serricorne, more commonly referred to as the cigarette beetle, cigar beetle, or tobacco beetle, is a small beetle that shares a remarkable resemblance with the drugstore beetle and the common furniture beetle. The cigarette beetle, along with the drugstore and furniture beetles, all belong to the beetle family Ptinidae. The cigarette beetle can be distinguished from A. punctatum by its flatter thorax, whereas the A. punctatum boasts a humped thorax. The cigarette beetle can be further differentiated from S. paniceum with its uniformly serrated antennae with unmodified apex, unlike the three-segmented apical "club" of S. paniceum. Additionally, L. serricorne has more no grooves in its elytra, or hardened wing covers, compared to A. punctatum and S. paniceum’s deep grooving.

<span class="mw-page-title-main">European rhinoceros beetle</span> Species of beetle

The European rhinoceros beetle is a large flying beetle belonging to the subfamily Dynastinae.

<i>Jalmenus evagoras</i> Species of butterfly

Jalmenus evagoras, the imperial hairstreak, imperial blue, or common imperial blue, is a small, metallic blue butterfly of the family Lycaenidae. It is commonly found in eastern coastal regions of Australia. This species is notable for its unique mutualism with ants of the genus Iridomyrmex. The ants provide protection for juveniles and cues for adult mating behavior. They are compensated with food secreted from J. evagoras larvae. The ants greatly enhance the survival and reproductive success of the butterflies. J. evagoras lives and feeds on Acacia plants, so butterfly populations are localized to areas with preferred species of both host plants and ants.

<i>Callosobruchus maculatus</i> Species of beetle

Callosobruchus maculatus is a species of beetles known commonly as the cowpea weevil or cowpea seed beetle. It is a member of the leaf beetle family, Chrysomelidae, and not a true weevil. It is often mistaken for Callosobruchus chinensis, another bean beetle species with a similar lifestyle. This common pest of stored legumes has a cosmopolitan distribution, occurring on every continent except Antarctica. The beetle most likely originated in West Africa and moved around the globe with the trade of legumes and other crops. As only a small number of individuals were likely present in legumes carried by people to distant places, the populations that have invaded various parts of the globe have likely gone through multiple bottlenecks. Despite these bottlenecks and the subsequent rounds of inbreeding, these populations persist. This ability to withstand a high degree of inbreeding has likely contributed to this species’ prevalence as a pest.

<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.

<i>Xeris spectrum</i> Species of sawfly

Xeris spectrum is a kind of horntail or wood wasp, that lives in coniferous forests. It is large wasp with a powerful ovipositor in females. Unlike other Siricid Wood wasps, Xeris spectrum does not have symbiotic fungi to aid its larvae as they burrow in the wood of fir and other conifer trees making it unique in the Siricidae. It is widespread and is found in large parts of Europe, Asia, Africa and North America.

<i>Polistes metricus</i> Species of wasp

Polistes metricus is a wasp native to North America. In the United States, it ranges throughout the southern Midwest, the South, and as far northeast as New York, but has recently been spotted in southwest Ontario. A single female specimen has also been reported from Dryden, Maine. P. metricus is dark colored, with yellow tarsi and black tibia. Nests of P. metricus can be found attached to the sides of buildings, trees, and shrubbery.

<i>Dinocampus coccinellae</i> Species of insect

Dinocampus coccinellae is a braconid wasp parasite of coccinellid beetles, including the spotted lady beetle, Coleomegilla maculata. D. coccinellae has been described as turning its ladybird host into a temporary "zombie" guarding the wasp cocoon. About 25% of Coleomegilla maculata recover after the cocoon they are guarding matures, although the proportion of other ladybird species which recover is much lower.

<i>Hemipepsis ustulata</i> Species of wasp

Hemipepsis ustulata is a species of tarantula hawk wasp native to the Southwestern United States. Tarantula hawks are a large, conspicuous family of long-legged wasps that prey on tarantulas by using their long legs to grapple with their prey and then paralyze them with a powerful sting. They are solitary, displaying lekking territorial behavior in their mating rituals.

<i>Carpophilus lugubris</i> Species of beetle

Carpophilus lugubris, commonly known as the dusky sap beetle, is a species of beetle in the genus Carpophilus. It is an agricultural pest of corn and tomato.

<i>Xyleborinus saxesenii</i> Species of beetle

Xyleborinus saxesenii, commonly known as the fruit-tree pinhole borer, is a species of ambrosia beetle in the family Curculionidae. It is native to the Palaearctic region but has been introduced in many locations, including North America. X. saxesenii typically live in freshly dead wood, but it has also been reported to attack live trees. Such attacks on live trees may lead to economic damage.

<i>Oemona hirta</i> Longicorn beetle native to New Zealand

Oemona hirta, the lemon tree borer, also known as the whistling beetle or the singing beetle, is a longhorn beetle endemic to New Zealand. Its larvae are generalist feeders, boring into the wood of a wide variety of trees, native and introduced. When citrus orchards were first established in New Zealand, this beetle started inflicting serious damage, and so gained the name "lemon tree borer". Four species within the genus Oemona have been identified, suggesting that more species could be found. When disturbed by predators or humans, the adult beetle stridulates creating a "rasp" or "squeak" sound by rubbing its thorax and head together against an area of thin ridges. Māori would eat a liquid called "pia manuka", which was produced by manuka trees when its wood was damaged by the larvae. When Captain Cook first arrived in NZ, his naturalists, Banks and Solander, collected a lemon tree borer in their first collection between 1769 and 1771. This oldest collected specimen can be found in the British Museum. A few years after the first collection, the species would be first described by the Danish naturalist Fabricius in 1775.

<i>Gnatocerus cornutus</i> Species of beetle

Gnatocerus cornutus, or the broadhorned flour beetle, is a common species of beetle in the Tenebrionidae family. It is distributed worldwide and is commonly found in warm, tropical regions, preferring grains, yeasts, and flours as its main diet. The total development time is about 47 days. G. cornutus is predominately found in mills as a storage pest and has a wide distribution.

References

  1. 1 2 Evans, Arthur V. (2014). Beetles of Eastern North America. Princeton University Press. ISBN   9780691133041.
  2. 1 2 3 4 5 Liles, M.P. (1956). "A study of the life history of the forked fungus beetle, Bolitotherus cornutus". Ohio J Sci. 56: 329–337. hdl:1811/4397.
  3. ↑ Heatwole, H.; Heatwole, A. (1 January 1968). "Movements, Host-Fungus Preferences, and Longevity of Bolitotherus cornutus (Coleoptera: Tenebrionidae)". Annals of the Entomological Society of America. 61 (1): 18–23. doi:10.1093/aesa/61.1.18.
  4. ↑ Open Access logo PLoS transparent.svg This article incorporates text from a scholarly publication published under a copyright license that allows anyone to reuse, revise, remix and redistribute the materials in any form for any purpose:
    Benowitz, K. M.; Brodie, E. D.; Formica, V. A. (2012). Proulx, Stephen R (ed.). "Morphological Correlates of a Combat Performance Trait in the Forked Fungus Beetle, Bolitotherus cornutus". PLOS ONE. 7 (8): e42738. Bibcode:2012PLoSO...742738B. doi: 10.1371/journal.pone.0042738 . PMC   3419742 . PMID   22916153. Please check the source for the exact licensing terms.
  5. 1 2 Lailvaux, S. P.; Hathway, J.; Pomfret, J.; Knell, R. J. (2005). "Horn size predicts physical performance in the beetle Euoniticellus intermedius (Coleoptera: Scarabaeidae)". Functional Ecology. 19 (4): 632. Bibcode:2005FuEco..19..632L. doi: 10.1111/j.1365-2435.2005.01024.x .
  6. ↑ Emlen DJ (1996) Artificial selection on horn length body size allometry in the horned beetle Onthophagus acuminatus (Coleoptera: Scarabaeidae). Evolution 50: 1219–1230. doi:10.2307/2410662
  7. ↑ Emlen, D. J.; Corley Lavine, L.; Ewen-Campen, B. (2007). "Colloquium Papers: On the origin and evolutionary diversification of beetle horns". Proceedings of the National Academy of Sciences. 104 (Suppl 1): 8661–8668. Bibcode:2007PNAS..104.8661E. doi: 10.1073/pnas.0701209104 . PMC   1876444 . PMID   17494751.
  8. 1 2 3 Conner JK (1988) Field measurements of natural and sexual selection in the fungus beetle, Bolitotherus cornutus. Evolution 42: 736–749. doi:10.2307/2408865.
  9. ↑ Formica, V. A.; McGlothlin, J. W.; Wood, C. W.; Augat, M. E.; Butterfield, R. E.; Barnard, M. E.; Brodie Iii, E. D. (2011). "Phenotypic Assortment Mediates the Effect of Social Selection in a Wild Beetle Population". Evolution. 65 (10): 2771–2781. doi: 10.1111/j.1558-5646.2011.01340.x . PMID   21967420.
  10. 1 2 Orlander, Evelyne. "Bolitotherus cornutus". Animal Diversity Web. Retrieved 2024-03-01.
  11. 1 2 3 Conner, Jeffrey; Camazine, Scott; Aneshansley, Daniel; Eisner, Thomas (1985-01-01). "Mammalian breath: trigger of defensive chemical response in a tenebrionid beetle (Bolitotherus cornutus)". Behavioral Ecology and Sociobiology. 16 (2): 115–118. doi:10.1007/BF00295144. ISSN   1432-0762. S2CID   35130398.
  12. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Liles, M. Pferrer. "A STUDY OF THE LIFE HISTORY OF THE FORKED FUNGUS BEETLE, BOLITOTHERUS CORNUTUS (PANZER)".
  13. ↑ "forked fungus beetle - Bolitotherus cornutus". entnemdept.ufl.edu. Retrieved 2024-03-01.
  14. ↑ Parmenter, Robert (April 1, 1988). "Factors Limiting Populations of Arid-Land Darkling Beetles (Coleoptera: Tenebrionidae): Predation by Rodents". academic.oup.com. Retrieved March 1, 2024.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.