Megalodacne

Megalodacne is a genus of fungivorous beetles in the family Erotylidae.[1]

Megalodacne
Megalodacne heros beetles from the United States feeding on bracket fungi
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Coleoptera
Family:	Erotylidae
Subfamily:	Megalodacninae
Genus:	Megalodacne Crotch, 1873
Type species
Ips fasciata (Fabricius, 1777)

Description

Adult beetles of the genus Megalodacne range in size from 9 to 22 millimetres (0.35 to 0.87 in), making them among the larger members of the family.[2][3]

Distinguishing characteristics of the genus along with other members of the subfamily Megalodacninae include large eyes and a lack of depressions in the club joint of the antennae. The first three tarsomeres are also cylindrical and of similar shape and size, while the fourth is significantly shorter.[4]

Species of the genus Megalodacne very closely resembles members of the genera Episcapha and Episcaphula (some members of which were formerly classified under Megalodacne).[5][6] They also often look superficially similar to several other beetles since the patterns of the markings of yellow, orange, or red on the elytra (called fascia) of Megalodacne are shared by many other beetle species.[2]

An example of which is the sap beetle (Nitidulidae) genus Glischrochilus.[7] Their native ranges sometimes overlap as well, making it easy to confuse the two (as with Megalodacne fasciatus, Megalodacne heros, and the nitulidid Glischrochilus fasciatus from eastern North America). The best way to tell them apart is by size, as sap beetles are generally small, ranging from 2 to 12 mm (0.08 to 0.47 in) in length. Glischrochilus reaches a maximum length of only 12 mm (0.47 in).[8] Megalodacne on the other hand are large beetles ranging from 9 to 22 mm (0.35 to 0.87 in).[7][9] The elytra of the sap beetles which most resemble Megalodacne also do not cover the whole abdomen and leave the last abdominal segment(s) exposed.[9] The elytra of Megalodacne, on the other hand, completely cover the abdomen.[10]

Ecology

Megalodacne species feed on harder bracket fungi than smaller members of the family.[2] The fungi eaten include Ganoderma[2] and Fomes species.[11]

Some tropical nocturnal species of Megalodacne are attracted to light.[4]

Life cycle

Megalodacne deposit eggs on the fungi on which they feed. Upon hatching, the larvae, like adults, also feed on the fruiting bodies of bracket fungi by burrowing into it...[12][13][14]

There are two kinds of larvae of Megalodacne depending on the species. In some species, the larvae are elongated and feed on fungi by drilling holes inside of it. In others, the larvae feed alongside adults by gnawing out shallow depressions on the fruiting bodies of fungi. The latter larvae are sluggish, heavily sclerotized, and somewhat flattened.[4] The larval stage takes about 2 to 3 months from egg to pupation. It is not uncommon to see adults feeding along with larvae.[15][16]

Taxonomy and systematics

Megalodacne was first described by George Robert Crotch in 1873.[17] The type species is Ips fasciata (now known as Megalodacne fasciata).[5] The genus Megalodacne is classified in the subfamily Megalodacninae, alongside the genera Episcapha and Episcaphula.[18]

List of species

Species of Megalodacne include:

• Megalodacne bellula (Lewis, 1883) – Japan, Korea, & China[4][6]
• Megalodacne chinensis (Crotch, 1876) – China[19]
• Megalodacne elongatula (Crotch, 1876) – Southeast Asia[5][20]
• Megalodacne fasciata (Fabricius, 1777) – eastern North America[21]
• Megalodacne grandipennis (Fairmaire, 1891) – Tanzania[22]
• Megalodacne grandis (Fabricius, 1792) - Africa[5][22]
• Megalodacne heros (Say, 1823) – eastern North America[21]
• Megalodacne immaculata (Chûjô and Kiuchi, 1963) – Japan[5]
• Megalodacne marginata (Arrow, 1925) – Assam[5]
• Megalodacne promensis (Arrow, 1925) – Burma, China[5]
• Megalodacne similima (Crotch, 1876) – Sarawak, Sumatra[5]
• Megalodacne varia (Gorham, 1889) – Malaysia[5]

References

1. Paul E. Skelley (2009). "Pleasing fungus beetles of the West Indies (Coleoptera: Erotylidae: Erotylinae)" (PDF). Insecta Mundi. 0082: 1–94.
2. Paul E. Skelley (March 2008). "Pleasing Fungus Beetles, Pseudischyrus, Tritoma, Megalodacne, Ischyrus spp. (Insecta: Coleoptera: Erotylidae)". Featured Creatures. University of Florida. Retrieved January 18, 2011.
3. Stephen Cresswell. "Megalodacne fasciata and Megalodacne heros, Pleasing Fungus Beetles". Insects of West Virginia. Archived from the original on November 24, 2010. Retrieved January 19, 2011. External link in |publisher= (help)
4. Piotr Węgrzynowicz (2002). "Morphology, phylogeny and classification of the family Erotylidae based on adult characters (Coleoptera: Cucujoidea)" (PDF). Genus. University of Wroclaw. 13 (4): 435–504. Archived from the original (PDF) on July 18, 2011. Retrieved May 6, 2011.
5. Michio Chûjô & Michitaka Chûjô (1988). "A Catalog of the Erotylidae (Insecta, Coleoptera) from the Old World (Excluding the Ethiopian Region)" (PDF). ESAKIA. Kyushu University Publications in Entomology. 26: 129–185. Archived from the original (PDF) on July 18, 2011. Retrieved May 6, 2011.
6. Michio Chûjô; Michitaka Chûjô & Lee Chang Eon (1993). "Erotylidae from Korea (Insecta, Coleoptera)" (PDF). ESAKIA. Kyushu University Publications in Entomology. 33: 99–108. Archived from the original (PDF) on August 25, 2011. Retrieved May 6, 2011.
7. Valerie J. Cervenka; Thomas C. Skalbeck; John F. Kyhl; Darren C. Blackford; Jennifer J. Juzwik & Steven J. Seybold (2001). How to identify common nitidulid beetles associated with oak wilt mats in Minnesota (PDF). North Central Research Station, U.S. Department of Agriculture.
8. Glischrochilus obtusus
9. Peter Hollinger (April 27, 2006). "Little Black Beetle with Orange - Glischrochilus fasciatus". http://bugguide.net/. Retrieved January 19, 2011. External link in |publisher= (help)
10. Arthur V. Evans & James N. Hogue (2006). Field Guide to Beetles of California. California Natural History Guide Series No. 88. Berkeley and Los Angeles, California: University of California Press. ISBN 978-0-520-24657-7. Retrieved January 19, 2011.
11. Michael A. Goodrich (1997). "New host records for Haematochiton elateroides Gorham (Coleoptera: Erotylidae)". The Coleopterists Bulletin. 51 (3): 276. JSTOR 4009421.
12. Mike Quinn. "Red-banded Fungus Beetle". Texas Entomology. Retrieved January 21, 2011. External link in |publisher= (help)
13. Gary Emberger (2008). "Perenniporia robiniophila". Messiah College. Retrieved January 21, 2011. External link in |publisher= (help)
14. Simon Hinkley & Ken Walker (2008). "Pleasing fungus beetle Dacne japonica Crotch, 1873 (Coleoptera: Erotylidae: Dacninae)". Pests and Disease Image Library. Archived from the original on August 21, 2008. Retrieved January 21, 2011. External link in |publisher= (help)
15. Skelley, Paul E. (1988). "Pleasing Fungus Beetles (Coleoptera: Erotylidae)" (PDF). Entomology Circular. Florida Department of Agricultural & Consumer Services, Division of Plant Industry (313). Archived from the original (PDF) on July 18, 2011. Retrieved January 21, 2011.
16. Paul E. Skelley (Sep 5, 2001). "Pleasing Fungus Beetles of North America Family Erotylidae". http://www.fsca-dpi.org/. Retrieved January 21, 2011. External link in |publisher= (help)
17. Troy Bartlett, Stephen Cresswell & Patrick Coin (11 March 2008). "Genus Megalodacne". Bug Guide. Retrieved 16 January 2011.
18. "Erotylidae". Joel Hallan's Biology Catalog. Texas A&M University. Retrieved January 18, 2011.
19. Michio Chûjô (1968). "Erotylid Beetles from South-China, Hainan, Taiwan and the Ryukyus" (PDF). Pacific Insects Monograph. Entomology Department, Bishop Museum. 10 (3–4): 539–550. ISSN 0078-7515. Retrieved May 6, 2011.
20. Michio Chûjô (1968). "Erotylid beetles from Thailand, Laos and Viet-Nam" (PDF). Pacific Insects Monograph. 10 (3–4): 551–573. ISSN 0078-7515.
21. Eric R. Eaton & Kenn Kaufman (2007). Kaufman field guide to insects of North America. Houghton Mifflin Harcourt. p. 166. ISBN 978-0-618-15310-7.
22. Roy Danielsson (February 20, 2009). "Coleoptera: Erotylidae present in the Entomological Museum of Lund University". Entomological Museum of Lund University, Sweden. Retrieved 16 January 2011.

External links

• Data related to Megalodacne at Wikispecies
• Media related to Megalodacne at Wikimedia Commons