Flea beetle

Flea beetle
The flea beetle is a small, jumping beetle of the leaf beetle family (Chrysomelidae), that makes up the tribe Alticini which is part of the subfamily Galerucinae. Historically the flea beetles were classified as their own subfamily.
Though most tribes of the Galerucinae are suspect of rampant paraphyly in the present delimitation, the Alticini seem to form a good clade.
Traditionally, the Alticini were separated from other Galerucinae by the presence of a metafemoral spring (i.e., jumping hind legs). Recent phylogenetic studies suggest that jumping hind legs evolved multiple times in the Galerucinae, rather than once, and that several genera should be transferred between Alticini and Galerucinae sensu stricto (or Galerucini in some classifications).
Description and ecology
The adults are very small to moderately sized Chrysomelidae (i.e. among beetles in general they are on the smallish side). They are similar to other leaf beetles, but characteristically have the hindleg femora greatly enlarged. These enlarged femora allow for the springing action of these insects when disturbed. Flea beetles can also walk normally and fly. Many flea beetles are attractively colored; dark, shiny and often metallic colors predominate.
Adult flea beetles feed externally on plants, eating the surface of the leaves, stems and petals. Under heavy feeding the small round holes caused by an individual flea beetle's feeding may coalesce into larger areas of damage. Some flea beetle larvae (e.g. of Phyllotreta species) are root feeders.
In adverse weather conditions (rain, for example) some flea beetles seek shelter in the soil. Some species, such as Phyllotreta cruciferae and P. striolata, prefer to leave their hideouts only during warm and dry weather. The German name Erdflöhe (literally "earth fleas") refers to their jumping ability and this behavior of hiding in the soil.
Relationship with humans
Flea beetles may be beneficial or may be pests, depending on the species.
Pest
Many major agricultural crops are attacked by flea beetles, including various cruciferous plants such as mustard and rapeseed (particularly canola in northwestern North America). Numerous garden plants are also subject to flea beetle feeding, such as flowers of Gardenia and Rothmannia by Altica species.
Flea beetles execute their most severe attacks during dry weather and are most active on sunny days. The larvae are known to chew roots.
Companion plant
Flea beetles can be deterred by a number of different companion plants, that can be grown intercropped in a garden to benefit neighboring plants. For example, thyme, catnip, and other kinds of mint cover up the scent of nearby plants.
Radishes, on the other hand, can be grown as a trap crop, luring the flea beetles away from more important crops. Since the root isn't harmed by the beetles, they remain useful, themselves.
A number of natural predators can be employed to keep flea beetles in check, including two that parasitize it: braconid wasps and tachinid flies. In both cases, the larval stage feeds on the flea beetle, while the adults feed on nectar and pollen; some species are even important pollinators. To encourage braconid wasps and tachinid flies, some types of flowers can be planted between crops: umbels such as caraway, herb fennel, coriander and Ammi majus, and simple open flowers such as California poppies and pot marigolds, as well as yarrows.
Beneficial insect
Other flea beetle species are beneficial, feeding on weeds and similar nuisance plants. A few species have even been introduced to various locations as biological control agents against some weeds. One important example is in the control of leafy spurge (Euphorbia virgata), an invasive weed in the United States. It has a toxic latex and is generally avoided by herbivores. Flea beetles of the genus Aphthona have been successfully introduced to control this plant.
Selected genera
This genus list is not complete. It is also partially from ITIS and might include genera placed elsewhere in other sources.
Acallepitrix J.Bechyné, 1956
Acrocyum Jacoby, 1885
Afroaltica Biondi & D'Alessandro, 2007
Agasicles Jacoby, 1904
Altica Geoffroy, 1762
Andersonoplatus Linzmeier & Konstantinov, 2018
Anthobiodes Weise, 1887
Aphthona Chevrolat in Dejean, 1836
Aphthonoides Jacoby, 1885
Apteropeda Chevrolat in Dejean, 1836
Argopistes Motschulsky, 1860
Argopus Fischer von Waldheim, 1824
Arrhenocoela Foudras, 1861
Asphaera Duponchel & Chevrolat, 1842
Aulacothorax Boheman, 1858
Batophila Foudras, 1860
Blepharida Chevrolat in Dejean, 1836
Capraita J.Bechyné, 1957
Cerataltica Crotch, 1873
Chaetocnema Stephens, 1831
Cornulactica Bechyné, 1955
Crepidodera Chevrolat in Dejean, 1836
†Crepidocnema Moskeyko et al., 2010
Derocrepis Weise, 1886
Dibolia Latreille, 1829
Disonycha Chevrolat in Dejean, 1836
Distigmoptera Blake, 1943
Dysphenges Horn, 1894
Epitrix Foudras in Mulsant, 1859
Glenidion H.Clark, 1860
Glyptina J.L.LeConte, 1859
Hemiglyptus Horn, 1889
Hemiphrynus Horn, 1889
Hermaeophaga Foudras, 1860
Heyrovskya Madar & Madar, 1968
Hippuriphila Foudras in Mulsant, 1859
Hornaltica Barber, 1941
Kashmirobia Konstantinov & Prathapan, 2006
Kuschelina J.Bechyné, 1951
Lanka Maulik, 1926
Longitarsus Berthold, 1827
Luperaltica Crotch, 1873
Lupraea Jacoby, 1885
Lysathia J.Bechyné, 1957
Lythraria Bedel, 1897
Mantura Stephens, 1831
Margaridisa J.Bechyné, 1958
Minota Kutschera, 1859
Mniophila Stephens, 1831
Mniophilosoma Wollaston, 1854
Monomacra Chevrolat in Dejean, 1836
Neocrepidodera Heikertinger, 1911
Nesaecrepida Blake, 1964
Nisotra Baly, 1864
Ochrosis Foudras, 1861
Oedionychis Latreille, 1829
Omophoita Chevrolat in Dejean, 1836
Orestia Chevrolat in Dejean, 1836
Pachyonychis H.Clark, 1860
Pachyonychus F.E.Melsheimer, 1847
Palaeothona Jacoby, 1885
Parchicola J.Bechyné and B.Springlová de Bechyné, 1975
Phydanis Horn, 1889
Phyllotreta Chevrolat in Dejean, 1836
Podagrica Chevrolat in Dejean, 1836
Pseudodibolia Jacoby, 1891
Pseudolampsis Horn, 1889
Pseudorthygia Csiki in Heikertinger and Csiki, 1940
Psylliodes Berthold, 1827
Sphaeroderma Stephens, 1831
Strabala Chevrolat in Dejean, 1836
Syphrea Baly, 1876
Systena Chevrolat in Dejean, 1836
Trichaltica Harold, 1876
Ugandaltica D'Alessandro & Biondi, 2018
See also
List of flea beetle genera
References
External links
Flea beetle description at Kansas State University
Flea Beetles, Kansas State University, July 2008
The Handbook of Palearctic Flea Beetles - identification of Palearctic flea beetle genera, along with morphology, host plant information, and literature references
"Flea Beetles" by W.S. Cranshaw, Colorado State University Extension entomologist and professor
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