Philonthus

Philonthus spinipes, copyright Andrey Ponomarev.

Belongs within: Philonthina.

Philonthus: too many staphylinids
Published 29 January 2017
Philonthus marginatus, copyright James K. Lindsey.

Working with staphylinids, it has to be said, can be horrible. They are treated as one of the most diverse of the beetle families—perhaps the most diverse of all—but compared to other diverse families they attract relatively little study. The majority of staphylinids are usually either very small or soft-bodied, not uncommonly both together, making them difficult to prepare and maintain as dry specimens. For the soft-bodied species, with their reduced elytra, many of the easily visible features that can be so useful for other beetle groups are obscure or unavailable. They also tend to be drab in coloration, without much in the way of striking patterning. As a result, it is often impossible to identify staphylinid species without examining minute features of the appendages or the genitalia. Something to keep in mind as you read the following.

Species of the genus Philonthus are relatively large as staphylinids go, often about half a centimetre in length, but they are certainly not free of the problems affecting other members of the family taxonomy-wise. The genus is massively diverse—over 1200 species have been described from around the world. Attempts have been made to break them down into more manageable chunks, such as through the recognition of subgenera, but these have mostly failed to gain much traction. Most recent authors have only recognised informal species groups within the greater mass.

Philonthus carbonarius, copyright James K. Lindsey.

In general, species of Philonthus are smooth, without excessive hairs, and have labial palps with the last segment fusiform and about as wide as the penultimate segment (Tottenham 1955; Stan 2012). Males have the aedeagus (the intromittent organ of the genitalia) rotated in the abdomen so its paramere (off-branch) is located on the left side rather than ventrally as in other genera (Tottenham 1955). Some species may have a metallic sheen to their coloration; others are a plainer black or reddish. Species may also differ in the number and arrangement of setae on the pronotum.

Where their lifestyles are known, most Philonthus are associated with decomposing organic matter such as animal dung, compost or leaf litter. Some are predators of other insects and insect larvae found in such habitats (such as fly larvae); these species have highly developed senses to locate decaying matter, and are strong fliers to disperse to suitable habitats (Majka et al. 2009). Some species of Philonthus may act as predators of other pest insects, helping to keep their numbers down.

Systematics of Philonthus
Philonthus Stephens 1829 [incl. Palaeophilonthus Coiffait 1972, Paragabrius Coiffait 1963]NT01
|--P. ocypoides groupT55
| |--P. balbus Tottenham 1955T55
| |--P. irritansT55
| |--P. lasti Tottenham 1955T55
| |--P. ocypoidesT55
| |--P. saltiT55
| `--P. tabius Tottenham 1955T55
`--P. (Spatulonthus Tottenham 1955)T55
|--P. (*S.) longicornis Stephens 1832 (see below for synonymy)T55
|--P. (S.) agilisT55
|--P. (S.) bestialis Bernhauer 1939T55
|--P. (S.) bishanus Tottenham 1955T55
|--P. (S.) bisignatus Boheman 1848 [incl. P. peregrinus var. pustulatus Bernhauer 1915]T55
|--P. (S.) cochleatusT55
|--P. (S.) deleterius Tottenham 1955T55
|--P. (S.) delusor Tottenham 1955T55
|--P. (S.) igacus Tottenham 1955T55
|--P. (S.) incognitus Bernhauer 1931T55
|--P. (S.) kasaiensis Bernhauer 1928T55
|--P. (S.) labdanus Tottenham 1955T55
|--P. (S.) limulus Tottenham 1955T55
|--P. (S.) maskinius Tottenham 1955 [incl. P. longicornis kristenseni Bernhauer 1931 non Bernhauer 1915]T55
|--P. (S.) minutus Boheman 1848T55
|--P. (S.) peregrinus Fauvel 1866T55
|--P. (S.) ponderosus Tottenham 1955T55
|--P. (S.) ridens Tottenham 1955T55
|--P. (S.) sanamus Tottenham 1955 (see below for synonymy)T55
|--P. (S.) tachyoryctides Jeannel & Paulian 1945T55
|--P. (S.) ugandae Bernhauer 1937 [incl. P. maculatus Bernhauer ms non Cameron 1920]T55
`--P. (S.) vestigator Tottenham 1955 (see below for synonymy)T55

Philonthus incertae sedis:
P. aeneusC01
P. affinisT55
P. albipesT55
P. altissimusT55
P. alutaceusNT01
P. aminius Tottenham 1955T55
P. atratusC01
P. bernhaueri Csiki 1901C01
P. bidentiformisT55
P. cafferT55
P. concinnusC01
P. cruentatus [incl. P. cruentatus var. extinctus]C01
P. cumaeusT55
P. cyanipennisN90
P. densicauda Bernhauer 1943T55
P. discoideusM96
P. dollmaniT55
P. ebeninus [=Staphylinus ebeninus]G89
P. fumariusT55
P. fusiformisT55
P. hepaticusM96
P. intermediusC01
P. iridescens Tottenham 1949T55
P. irinusT55
P. jacksoni Cameron 1950T55
P. jurgansT55
P. lepidus [incl. P. lepidus var. mongolicus Csiki 1901]C01
P. limbukus Tottenham 1955T55
P. linkiC01
P. maculipennisT55
P. micansC01
P. moquerysiT55
P. nairobianus Cameron 1950T55
P. nigritulusG89
P. nitidusC01
P. ornatusM96
P. pacificusM96
P. parciventrisT55
P. peliomerusT55
P. pellax Tottenham 1955T55
P. piceicoxis [=P. bisignatus var. piceicoxis, P. peregrinus var. piceicoxis]T55
P. piligerC01
P. porus Tottenham 1955T55
P. procerulus [=Staphylinus procerulus]G89
P. punctipennisG89
P. quisquiliariusC01
P. reinecki Schubert 1902T55
P. rubrovittatusT55
P. sparsus Lucas 1846E12
P. spinipesLC20
P. splendensC01
P. subaeneicollis Bernhauer 1931T55
P. subcingulatus [=Quedius subcingulatus]M96
P. tenuicornisV09
P. tumulinus Tottenham 1955T55
P. turbidusG89
P. umbratilisC01
P. variansC01
P. ventralis Grav. 1802 (see below for synonymy)FS90
P. vernalisC01
P. vilis Er. 1839FS90
P. vittigerT55

Philonthus ventralis Grav. 1802 [incl. P. anthrax Grav. 1802, P. fulvipes, P. immundus, P. picicollis, P. rotundiceps]FS90

Philonthus (*Spatulonthus) longicornis Stephens 1832 [incl. P. coprophilus Jarrige 1947, P. longicornis var. rubromaculatus Bernhauer 1915 non Blanchard 1843]T55

Philonthus (Spatulonthus) sanamus Tottenham 1955 [=T. nitidicollis Klug 1855 non Lacordaire 1835; incl. P. sanamus f. placatus Tottenham 1955]T55

Philonthus (Spatulonthus) vestigator Tottenham 1955 [incl. P. varians var. scutatus Eppelsheim 1895 (preoc.), P. bisignatus var. scutatus, P. peregrinus var. scutatus]T55

*Type species of generic name indicated

References

[C01] Csiki, E. 1901. Bogarak [Coleopteren]. In: Horváth, G. (ed.) Zichy Jenő Gróf Harmadik Ázsiai Utazása [Dritte Asiatische Forschungsreise des Grafen Eugen Zichy] vol. 2. Zichy Jenő Gróf Harmadik Ázsiai Utazásának Állattani Eredményei [Zoologische Ergebnisse der Dritten Asiatischen Forschungsreise des Grafen Eugen Zichy] pp. 75–120. Victor Hornyánszky: Budapest, and Karl W. Hierseman: Leipzig.

[FS90] Fleutiaux, E., & A. Sallé. 1890. Liste des coléoptères de la Guadeloupe et descriptions d’espèces nouvelles. Annales de la Société Entomologique de France, 6e série 9: 351–484.

[G89] Gestro, R. 1889. Viaggio ab Assab nel Mar Rosso dei signori G. Doria ed O. Beccari con il R. Avviso “Esploratore” dal 16 Novembre 1879 al 26 Febbraio 1880.—IV. Coleotteri. Annali del Museo Civico di Storia Naturale di Genova, Serie 2a, 7: 5–72.

[LC20] Lü, L., C.-Y. Cai, X. Zhang, A. F. Newton, M. K. Thayer & H.-Z. Zhou. 2020. Linking evolutionary mode to palaeoclimate change reveals rapid radiations of staphylinoid beetles in low-energy conditions. Current Zoology 66 (4): 435–444.

Majka, C. G., J.-P. Michaud, G. Moreau & A. Smetana. 2009. Philonthus hepaticus (Coleoptera, Staphylinidae) in eastern Canada: are distribution gaps distinctive features or collecting artifacts? ZooKeys 22: 347–354.

[M96] Masters, G. 1896. Catalogue of the described Coleoptera of Australia. Supplement, part II. Dytiscidae, Gyrinidae, Hydrophyllidae, Staphylinidae, Pselaphidae, Paussidae, Silphidae, Scaphididae, Histeridae, Phalacridae, Nitidulidae, Trogositidae, Colydiidae, Cucujidae, Cryptophagidae, Lathridiidae, Mycetophagidae, Dermestidae, Byrrhidae, Parnidae, Heteroceridae. Proceedings of the Linnean Society of New South Wales 21 (Suppl.): 695–754.

[N90] Newton, A. F., Jr. 1990. Insecta: Coleoptera Staphylinidae adults and larvae. In: Dindal, D. L. (ed.) Soil Biology Guide pp. 1137–1174. John Wiley & Sones: New York.

[NT01] Newton, A. F., M. K. Thayer, J. S. Ashe & D. S. Chandler. 2001. Staphylinidae Latreille, 1802. In: Arnett, R. H., Jr & M. C. Thomas (eds) American Beetles vol. 1. Archostemata, Myxophaga, Adephaga, Polyphaga: Staphyliniformia pp. 272–418. CRC Press: Boca Raton.

Stan, M. 2012. On the species of Philonthus Stephens (Coleoptera: Staphylinidae: Staphylininae: Staphylinini: Philonthina) in the collections of Romanian natural history museums. Travaux du Muséum National d’Histoire Naturelle “Grigore Antipa” 55 (2): 233–276.

[T55] Tottenham, C. E. 1955. Studies in the genus Philonthus Stephens (Coleoptera: Staphylinidae). Parts II, III, and IV. Transactions of the Royal Entomological Society of London 106 (3): 153–195.

[V09] Verdcourt, B. (ed.) 2009. Additions to the wild fauna and flora of the Royal Botanic Gardens, Kew. XXVI. Miscellaneous records. Kew Bulletin 64 (1): 183–194.

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