Pictured rove beetle

{{Short description|Species of beetle}} {{Speciesbox | image = thinopinus_pictus.jpg | image_caption = Specimen from a shore on Olympic Peninsula, Washington | display_parents = 4 | genus = Thinopinus | parent_authority = LeConte, 1852 | species = pictus | authority = LeConte, 1852 }}

The '''pictured rove beetle''' ('''''Thinopinus pictus''''') is a wingless rove beetle which lives on the sandy beaches of the West Coast of the United States from southern Alaska to Baja California.<ref name="Moore">{{cite journal |author=I. Moore |year=1977 |title=The color phases of ''Thinopinus pictus'' Leconte (Coleoptera: Staphylinidae) |journal=The Coleopterists Bulletin |volume=31 |issue=4 |pages=377–378}}</ref> It is nocturnal, emerging at night from temporary sand burrows to feed on beach hoppers (''Orchestoidea'').<ref name="Craig">{{cite journal |author=P. C. Craig |year=1970 |title=The behavior and distribution of the intertidal sand beetle, ''Thinopinus pictus'' (Coleoptera: Staphylinidae) |jstor=1933627 |journal=Ecology |volume=51 |issue=6 |pages=1012–1017 |doi=10.2307/1933627|bibcode=1970Ecol...51.1012C }}</ref> It is the only species in the genus '''''Thinopinus'''''.<ref>{{Catalogue of Life|id=8VS5L|title=''Thinopinus'' LeConte, J. L., 1852|access-date=18 March 2026}}</ref>

==Identification== Like other rove beetles, ''T. pictus'' has shortened elytra, so that most of its abdomen is exposed. Males average {{convert|17|mm}}, females average {{convert|18|mm|abbr=on}}. Males possess a cleft in the last abdominal sternite, which makes them readily discernible from females.<ref name="Craig"/> Their cryptic coloration varies geographically in response to lighter colored sand in the southern part of their range. Populations north of central California tend to be darker in response to the dark volcanic sand, while those in the southern range are quite pale. Because of this variation, ''T. pictus'' was once thought to be made up of two subspecies.<ref name="Moore"/>

==Ecology== ''Thinopinus pictus'' inhabits the sandy intertidal zone; during the day, they hide in temporary sand burrows or under kelp and beach debris with a preference to inhabit the wettest and softest sand available.<ref name="Craig"/> At night they emerge and move to the high tide level to find prey.<ref>{{cite journal |author=Laura J. Richards |year=1982 |title=Prey selection by an intertidal beetle: field test of an optimal diet model |journal=Oecologia |volume=55 |issue=3 |pages=325–332 |doi=10.1007/BF00376920|pmid=28309973 |bibcode=1982Oecol..55..325R |s2cid=31962855 }}</ref> Individuals switch between inactive ambush predation and active foraging for their prey, which consists mostly of beach hoppers (Amphipoda).<ref>{{cite journal |author=Laura J. Richards |year=1983 |title=Feeding and activity patterns of an intertidal beetle |journal=Journal of Experimental Marine Biology and Ecology |volume=73 |issue=3 |pages=213–224 |doi=10.1016/0022-0981(83)90048-5}}</ref> They have also been observed eating beach flies, isopods, and other ''T. pictus''.<ref name="Craig"/> Males seem to feed less than females, but are more active than females, possibly to increase the chance of finding a mate.<ref>{{cite journal |author=Laura J. Richards |year=1984 |title=Field studies of foraging behaviour of an intertidal beetle |journal=Ecological Entomology |volume=9 |issue=2 |pages=189–194 |doi=10.1111/j.1365-2311.1984.tb00714.x|bibcode=1984EcoEn...9..189R |s2cid=85673562 }}</ref>

==Reproduction== The breeding season is thought to be from August to October. Dissected females have been shown to carry only 2–3 eggs, which are oviposited singly in the sand. These beetles likely have long lifespans in order to reproduce sufficiently.<ref name="Craig"/> In the laboratory, eggs hatch at about 14 days. Larvae are whitish with black markings. The duration of their instars is unknown.<ref name="Craig"/>

==References== {{Reflist|2}}

==External links== *http://bugguide.net/node/view/321754 *{{YouTube|id=5r1bcF6vNw0|title=''Thinopinus pictus'' feeding}}

Category:Staphylininae Category:Beetles described in 1852 Category:Beetles of North America Category:Wingless beetles Category:Taxa named by John Lawrence LeConte