Mordellidae

Tumbling flower beetles
Imago of unidentified species; note the "pintail"
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Coleoptera
Superfamily:	Tenebrionoidea
Family:	Mordellidae Latreille, 1802
Subfamilies
Ctenidiinae Franciscolo, 1951 Mordellinae Latreille, 1802 †Praemordellinae
Synonyms
Liaoximordellidae

Mordellidae is a family of beetles commonly known as tumbling flower beetles for the typical irregular movements they make when escaping predators, or as pintail beetles due to their abdominal tip which aids them in performing these tumbling movements. Worldwide, there are about 1500 species.^[1]

The apparently tumbling movements are composed of a series of very rapid separate jumps (each jump of a duration of approximately 80 ms). They result from the beetle's efforts to get itself back into take-off position for flight when it has been in either lateral or dorsal position. Each individual jump should be considered as an extended rotation, performed by one leg of the third leg pair (Metapodium ). Depending on whether the left or the right metapodium is used as the leg that provides the leverage for take-off, change occurs in the direction of the jump. The energy for propulsion varies with the beetle's immediate muscle work. Resultantly, jump lengths and heights vary, with rotation frequencies recorded up to 48 rotation per second (Mordellochroa abdominalis) around the gravitation centre of the body's longitudinal axis. Additional revolving round the transverse axis (at lower frequency) effects spiralling summersaults that are perceived as tumbling. The pintail (pygidium) is of no significance for the jump. Technically similar jumps, though less powerful, can be observed in family Serropalpidae (genus: Orchesia) and family Scrabtiidae (genus: Anaspis). As both these groups of beetles are closely related to family Mordellidae, it may be assumed that it is due to their common phylogenetic roots that they have the same capacity of this tumbling form of locomotion. It can, therefore, not be ascribed specifically to Mordellidae. ^[2]

Systematics

Adult Tomoxia lineella (Mordellinae: Mordellini)

Larva of Mordellistena sp. (Mordellinae: Mordellistenini) larva inside a goldenrod gall made by the fly Eurosta solidaginis

Adult female Tolidopalpus nitidicoma (Mordellinae: Mordellistenini) from lateral

This family has two living subfamilies – Mordellinae and Ctenidiinae – and a prehistoric one known only from fossils (Praemordellinae). Another fossil genus, Liaoximordella, was previously treated as distinct monotypic family Liaoximordellidae, but is now regarded as very primitive and probably basal member of the Mordellidae.

Selected genera

This list is incomplete; you can help by expanding it.

Genera of tumbling flower beetles, with some notable species also listed, include:

Basal/incertae sedis

• †Liaoximordella Wang, 1993 (fossil)

†Praemordellinae (fossil)

• †Bellimordella Liu, Zhao & Ren, 2008
• †Mirimordella Liu, W.Lu & Ren, 2007
• †Praemordella Scegoleva-Barovskaja, 1929

Ctenidiinae

• Ctenidia Laporte de Castelnau, 1840

Mordellinae
Tribe Conaliini Ermisch, 1956

• Conalia Mulsant and Rey, 1858
• Glipodes LeConte, 1862
• Isotrilophus Liljeblad, 1945
• Pseudoconalia
• Xanthoconalia

Tribe Mordellini Latreille, 1802

• Glipa LeConte, 1859
• Hoshihananomia Kôno, 1935
• Mordella
• Paramordellaria Costa, 1854
• Tolidomordella Schilsky, 1908
• Tomoxia Ermisch, 1968
• Variimorda
  • Variimorda villosa
• Yakuhananomia Ermisch, 1950

Tribe Mordellistenini Latreille, 1802

• Falsomordellistena Ermisch, 1941
• Glipostenoda Ermisch, 1950
• Mordellistena Costa, 1854
• Mordellochroa Emery, 1876
• Pseudotolida Ermisch, 1950
• Tolidopalpus Ermisch, 1952

Tribe Reynoldsiellini Latreille, 1802

• Reynoldsiella

Tribe Stenaliini Latreille, 1802

• Pselaphostena Franciscolo, 1950
• Stenalia
• Stenaliodes

Footnotes

1. ^ Ivie (2002)
2. ^ Reuter, Michael: „Studies on the functional morphology of the jump in tumbling-flower beetles (Coleoptera, Mordellidae)“ Acta biologica benrodis 7, 99-133 (1995)

References

• Ivie, Michael A. (2002): [Mordellidae]. In: Arnett, Ross H. & Thomas, Michael Charles: American Beetles (Vol. 2: Polyphaga: Scarabaeoidea through Curculionoidea). CRC Press. ISBN 9780849309540

External links

Nomen.at