Glischrochilus Quadripunctatus 2

''Glischrochilus'' (sometimes misspelled as ''Glisrochilus'') is a genus of sap-feeding and predatory beetles under the family Nitidulidae, subfamily Cryptarchinae. Most members of this genus are commonly known as picnic beetles or beer bugs.

Description

''Glischrochilus'' are oblong shiny black beetles with attractive yellow, red, or orange markings on their elytra. Their elytra are short and expose the upper surface of their last abdominal segments, a good way to distinguish them from the superficially similar but generally larger '' Megalodacne'' beetles. They are so similar that some species of ''Glischrochilus'' were once classified along with ''Megalodacne'' under the now reclassified genus ''Ips''.

Like other nitulidid beetles, adult ''Glischrochilus'' can be distinguished from other kinds of sap-feeding beetles by their characteristic 11-segmented antennae that end with a 3-segmented ball-like club. ''Glischrochilus'' are among the largest of the nitulidid beetles, but they are still generally smaller in comparison to other beetles, averaging at only in length, with larger specimens at long.

''Glischrochilus'' eggs are sausage-shaped and milky white. Eggs are laid during spring near decaying plant matter. Larvae are about long and feed for three weeks on fermenting juices and then pupate. It takes a little over a month for picnic beetles to develop from egg to adult and only one generation is produced each year.

Ecology

''Glischrochilus'' beetles from the subgenus ''Librodor'', consisting the majority of species in the genus, feed on exuding sap from injured trees and decaying vegetable or fungal matter. They are also attracted to ripening fruits, as well as beer, vinegar, wine, fruit juice and fermenting beverages. They frequently drown as they feed, rendering these liquids unsuitable for consumption. They congregate in large numbers when such beverages are present, often ruining picnics and outdoor gatherings like barbecues, earning them their common names of 'picnic beetles', 'picnic bugs', or 'beer bugs'. Researchers who wish to attract the bugs use bait that contains beer, molasses, vinegar, pineapple and other ingredients.

''Glischrochilus'' beetles from the subgenus ''Glischrochilus'' on the other hand are facultative and obligatory predators of soft invertebrates (including insect larvae) living under tree barks.

Species from both subgenera are found in North America and Eurasia.

''Glischrochilus'' are also known to be involved in the transmission of the plant pathogenic fungi ''Ceratocystis'' and ''Fusarium''. They are also considered pests of certain fruit and vegetable crops like strawberries, corn, tomatoes, apricot, muskmelons, raspberries, and peaches. They normally only become a problem when fruits are damaged or are overripe and beginning to ferment. They are difficult to control as they are primarily attracted to the odor of food. Methods of control include scent baits and removing damaged or overripe fruits.

Taxonomy

''Glischrochilus'' belongs to the subfamily Cryptarchinae under the tribe Cryptarchini. It contains two subgenera, ''Glischrochilus'' and '' Librodor''.

They were first described by the German entomologist Edmund Reitter in 1873. The name ''Glischrochilus'' is derived from the Greek words ' (sticky) and (', lip).

List of species

The following list may be incomplete or inaccurate:

*Subgenus ''Glischrochilus'' Reitter, 1873
** '' Glischrochilus biguttulus'' (Motschulsky, 1860)
** '' Glischrochilus confluentus'' (Say)
** '' Glischrochilus cruciatus'' (Motschulsky, 1860)
** '' Glischrochilus lecontei'' (Brown, 1931)
** '' Glischrochilus moratus'' (Brown)
** '' Glischrochilus obtusus'' (Say)
** '' Glischrochilus quadripunctatus'' (Linnaeus, 1758) – European bark beetle predator
** '' Glsichrochilus vittatus'' (Say)
*Subgenus ''Librodor'' Reitter, 1884
** '' Glischrochilus affinis'' Kirejtshuk, 1984
** '' Glischrochilus binaevus'' (Reitter, 1879)
** '' Glischrochilus christophi'' (Reitter, 1879)
** '' Glischrochilus clavatus'' Reitter, 1884
** '' Glischrochilus fasciatus'' (Olivier, 1790) – red-spotted sap beetle
** '' Glischrochilus grandis'' (Tournier, 1872)
** '' Glischrochilus hortensis'' (Fourcroy, 1785)
** '' Glischrochilus ipsoides'' (Reitter, 1879)
** '' Glischrochilus japonicus'' (Motschulsky, 1858)
** '' Glischrochilus jelineki'' Lasoń, 2009
** '' Glischrochilus pantherinus'' (Reitter, 1879)
** '' Glischrochilus parvipustulatus'' (Kolbe, 1886)
** '' Glischrochilus quadriguttatus'' (Fabricius, 1776)
** ''Glischrochilus quadrisignatus'' (Say, 1835) – four-spotted sap beetle or picnic beetle
** '' Glischrochilus rufiventris'' (Reitter, 1879)
** '' Glischrochilus sanguinolentus'' (Olivier, 1790)
** '' Glischrochilus siepmanni'' (W. J. Brown)
** '' Glischrochilus subcylindricus'' Reitter, 1884

* Species '' Glischrochilus becvari'' Jelinek, 1999

* Species '' Glischrochilus forcipatus'' Fairmaire, 1889
* Species '' Glischrochilus vittatus'' (Say, 1835)

References

Notes

: For example
Finsberg, T. A. C. 2009. Insektsliv och vegetation vid brandfältet på Stora Fjället ett år efter, pp.13

External links

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{{Taxonbar, from=Q3108901

Nitidulidae