Rove Beetles of the World, Staphylinidae (Insecta: Coleoptera: Staphylinidae)1 J
Total Page:16
File Type:pdf, Size:1020Kb
EENY114 Rove Beetles of the World, Staphylinidae (Insecta: Coleoptera: Staphylinidae)1 J. Howard Frank and Michael C. Thomas2 Introduction Classification The family Staphylinidae belongs to the suborder Polyphaga Phylogeny of the order Coleoptera (beetles). The superfamily Staphy- Four phyletic lines are now included in Staphylinidae linoidea includes the small families Hydraenidae, Ptiliidae, (Lawrence and Newton 1995): Agyrtidae, Leiodidae, and Silphidae, and the huge family Staphylinidae. • subfamilies Glypholomatinae, Microsilphinae, Omaliinae, Empelinae, Proteininae, Micropeplinae, Neophoninae, SUBORDER Polyphaga—SUPERFAMILY Staphylinoidea— Dasycerinae, Protopselaphinae, Pselaphinae, and FAMILY Staphylinidae Scydmaeninae; At present, more species of beetles are known than of any • subfamilies Phloeocharinae, Olisthaerinae, Tachyporinae, other insect order. As now constituted, Staphylinidae are Trichophyinae, Habrocerinae, and Aleocharinae; the largest family of beetles, with over 63,000 species known • subfamilies Trigonurinae, Apateticinae, Scaphidiinae, worldwide and probably over 75% of tropical species still Piestinae, Osoriinae, and Oxytelinae; undescribed. It is the largest family in the British Isles and • subfamilies Oxyporinae, Megalopsidiinae, Steninae, in America north of Mexico, and it may prove to be so in Euaesthetinae, Solieriinae, Leptotyphlinae, Pseudopsinae, other regions when huge numbers of now-unknown species Paederinae, and Staphylininae. are described (if they are described before they become extinct by habitat destruction). In the future, systematists The former taxa Brathinidae (now just part of subfamily may, however, choose to split the family into four phyletic Omaliinae), Dasyceridae (now subfamily Dasycerinae), lines to form four families. This document takes a world- Empelidae (now subfamily Empelinae), Glypholomatini wide perspective, emphasizing the role of the extremely few (formerly a tribe of Silphidae), Microsilphinae (formerly species that have been studied; identification is far beyond a subfamily of Silphidae), Pselaphidae (now subfamily the scope of this document because of the size of the family. Pselaphinae), Scydmaenidae (now subfamily Scydmaeni- nae), and Scaphidiidae (now subfamily Scaphidiinae) of earlier authors are here in Staphylinidae. 1. This document is EENY114, one of a series of the Entomology and Nematology Department, UF/IFAS Extension. Original publication date September 1999. Revised April 2016 and October 2019. Visit the EDIS website at https://edis.ifas.ufl.edu for the currently supported version of this publication. This document is also available on the Featured Creatures website at http://entnemdept.ifas.ufl.edu/creatures/. 2. J. Howard Frank, retired professor, Entomology and Nematology Department; and Michael C. Thomas, retired, Florida Department of Agriculture and Consumer Services, Division of Plant Industry; UF/IFAS Extension, Gainesville, FL 32611. The Institute of Food and Agricultural Sciences (IFAS) is an Equal Opportunity Institution authorized to provide research, educational information and other services only to individuals and institutions that function with non-discrimination with respect to race, creed, color, religion, age, disability, sex, sexual orientation, marital status, national origin, political opinions or affiliations. For more information on obtaining other UF/IFAS Extension publications, contact your county’s UF/IFAS Extension office. U.S. Department of Agriculture, UF/IFAS Extension Service, University of Florida, IFAS, Florida A & M University Cooperative Extension Program, and Boards of County Commissioners Cooperating. Nick T. Place, dean for UF/IFAS Extension. Fossils Pleistocene fossil Staphylinidae have been reported from peat bogs in northeastern North America and from Europe. They seem to be of extant species and help to show former distribution of some of these species. Oligocene fossils are from amber from the Baltic, the Dominican Republic, and elsewhere, and from shales in the United States (Colorado), France, Germany, and elsewhere. Most of these are recognizably members of modern genera. Deposits from Figure 1. Representative adults of four subfamilies (left to right): the mid-Cretaceous to lower Jurassic in Eurasia have also Proteinus thomasi Frank (Proteininae) 1.5 mm; Coproporus rutilus yielded fossils. Most of these resemble members of modern (Erichson) (Tachyporinae) 3.8 mm; Scaphidium quadriguttatum (Say) subfamilies. The oldest recorded staphylinid, more than 200 (Scaphidiinae) 4.3 mm; Neobisnius ludicrus (Erichson) (Staphylininae) 4.1 mm. million years old, is from the upper Triassic of the United Credits: M. C. Thomas, Division of Plant Industry States (Virginia). Species-level identification of present-day Non-entomologists sometimes confuse Staphylinidae staphylinids normally requires dissection, at least of the with the order Dermaptera. However, the non-opposable genitalia; when this cannot be done with fossil specimens, valvulae (appendages of the ninth abdominal segment) they have limited value. are not the opposable forcipes of Dermaptera, and the radial wing-folding pattern of Dermaptera is unlike that of Appearance Staphylinidae. Adults The length of adult Staphylinidae ranges from less than Immature Stages 1 mm to 40 mm. Most are under 7 mm long. Most have Staphylinid eggs typically are white, spherical, spheroidal, short elytra, exposing several abdominal segments, but or pyriform (pear-shaped). Eggs of some genera in the it would be an error to imagine that all have short elytra, subfamily Staphylininae (e.g., Philonthus) have pronounced or that all beetles with short elytra are Staphylinidae. surface sculpture, allowing identification at least to the Typically, they are slender with short elytra and powerful species-group level. Larvae are campodeiform (sometimes abdominal musculature that renders them very flexible called staphyliniform), meaning they are elongated and and thus able to enter narrow crevices. Those that have flattened). In some subfamilies (Paederinae, Staphylininae, short elytra trade flexibility for exposure, rendering them and to a lesser extent in their immediate relatives) the subject to desiccation and dependent upon humid habitats. head is relatively more heavily sclerotized and there is a Abdominal segments are surrounded by sclerotized plates distinct “neck” (nuchal constriction of the head). Prepupae (a large dorsal plate called a tergite, a large ventral plate of the subfamily Steninae, most species within subfamily called a sternite, and up to two pairs of dorso-lateral plates Aleocharinae, and Astenus (Paederinae) spin a silken called paratergites) with membranous connections. In some cocoon in which they pupate. Pupae are obtect, pigmented, genera (e.g., Paederinae, Euaesthetinae, and Osoriinae, and and sclerotized in the subfamily Staphylininae, but exarate, partially so in Steninae) the tergites-paratergites-sternites white, and unsclerotized in all the other subfamilies. In plates are fused into rings around each segment, probably general, the immature stages develop rapidly, in a few days limiting water loss. The length of adults (Figure 1), which is to a few weeks, and the adults are long-lived. nevertheless normally used to express size, is an inaccurate determinant of size because abdominal segments typically Habitat and Food can be telescoped, making the body appear longer when under moist conditions and alive, but shorter when dried Habitat and dead. A lack of eyes has evolved in some soil-inhabiting Staphylinidae occupy almost all moist environments (Leptotyphlinae) and cave-inhabiting species, and wing- throughout the world. Because none of them is truly lessness has evolved in species occupying environments aquatic, they do not live in open waters; although winged including mountains, the soil, caves, and seashores. adults may be skimmed from the sea surface far from land, their presence is due to misadventure but attests to their dispersive ability. They live in leaf litter of woodland and forest floors and grasslands. They concentrate in fallen decomposing fruits; the space under loose bark of fallen, Rove Beetles of the World, Staphylinidae (Insecta: Coleoptera: Staphylinidae) 2 decaying trees; drifted plant materials on banks of rivers Eulissus (Staphylininae) on adult dung-inhabiting scarab and lakes; and dung, carrion, and nests of vertebrate beetles. Aleochara (Aleocharinae) has evolved to become animals. Several hundred species live only on seashores. parasitoidal in fly puparia. Many are specialized to exist in nests of social insects. Many inhabit caves, underground burrows of vertebrate animals, Behavior and smaller soil cavities, even of burrows that they (a few of them) excavate. Many live in mushrooms. Adults and even Presocial or Subsocial Behavior larvae of a few are associated with living flowers. Others Such behavior is known in Bledius and Platystethus (Oxy- climb on plants, especially at night, and hunt for prey. A few telinae) and Eumicrota (Aleocharinae). Adults construct seem to live with terrestrial snails. Their distribution in arid chambers—Bledius in sandy or muddy shores, Platystethus environments is restricted to moist microhabitats. in the dung of ungulates, and Eumicrota in mushrooms—in which they deposit and guard their eggs and young. Food A little about the feeding habits of Staphylinidae has been Relationships with Social and Communal deduced from casual observations by many observers, Insects from dissections