Description
Potentially Misidentified Species - Labidura riparia is also a cosmopolitan introduced species known from the shores of rivers and oceans (Arnett 1993; Blatchley 1920), known from SC-FL (Rehn and Hebard 1916 ). Euborellia annulipes is also a cosmopolitan introduced species, known mainly from terrestrial habitats, MA-FL, and CA (Arnett 1993), but also from strandlines and elsewhere (Blatchley 1920; Langston 1974; Vickery and Kevan 1985). Doru aculeatum is a native species primarily from marsh habitats in the southeast United States (Blatchley 1920), but collected in a brackish MD tidal marsh (Magruders Landing, Patuxent River) (Bickley and Seek 1975). Of the species listed, E. annulipes is most similar to A. maritima in overall proportions.
Taxonomy
| Kingdom | Phylum | Class | Order | Family | Genus |
|---|---|---|---|---|---|
| Animalia | Hexapoda | Insecta | Dermaptera | Anisolabidae | Anisolabis |
Synonyms
Invasion History
Chesapeake Bay Status
| First Record | Population | Range | Introduction | Residency | Source Region | Native Region | Vectors |
|---|---|---|---|---|---|---|---|
| 1916 | Established | Stable | Introduced | Regular Resident | Western Atlantic | Eastern Atlantic | Shipping(Dry Ballast; Unspecified) |
History of Spread
Anisolabis maritima, (Seaside Earwig) was first described from the Mediterranean (Italy) in 1832 (Scudder 1876a; Langston 1974). Its native region is somewhat uncertain, because this species was probably transported widely by shipping before its description (Hincks 1947). The Mediterranean region, from which it was described, seems a likely choice (Carlton 1979; Cohen and Carlton 1995). It was subsequently found to be very widely distributed in temperate to tropical coastal habitats (Scudder 1876a), on all continents, and many islands, including the West Indies (Rehn and Hebard 1917), Mauritius (Hincks 1947), Hawaii (Cohen and Carlton 1995), the Canary Islands, and New Zealand (Langston 1974). This insect, because of its preference for shoreline debris, is considered to have a high potential for transport by shipping (Carlton 1979), and has probably been transported by humans over most of its present range (Scudder 1876a; Hincks 1947).
Anisolabis maritima was first collected in North America in South Carolina in 1853 (Langston 1974). They are abundant at Woods Hole MA (Fofonoff personal observation). On the Atlantic coast, it was known from Key West (FL) to NC by 1876 (Scudder 1876b), and reported from the shore of Long Island Sound (Cold Spring Harbor NY) (Bennett 1904). Bennett considered these insects to be rare in New England, but by 1924, they were known from ME to CT (Morse 1920). On the Pacific Coast, A. maritima was first reported from Laguna Beach CA, and is now found from CA to British Columbia (Carlton 1979; Cohen and Carlton 1995; Langston 1974; Vickery and Kevan 1985). On the Atlantic coast, it has been considered to be most likely introduced (Morse 1920; Scudder 1876b), though Scudder noted that 'This may be indigenous, but it occurs over nearly the whole world'. The fact that the early records of this species came from the southeast, suggests that this earwig may have extended its range northward, considering the high frequency of collectors in the Northeast.
In the Chesapeake Bay region, we have only found two published records of this species. However, based on its distribution elsewhere, it is probably present along much of the shoreline of the Chesapeake and the adjacent Atlantic coast.
Lower Bay - It was collected at Fort Monroe, Hampton VA, before 1916 (Rehn and Hebard 1916). The museum specimens from this site are undated (United States National Museum of Natural History collections). A specimen was collected at the Virginia Colonial Park (Yorktown-Jamestown) in 1950 (U. S. Museum of Natural History collections).
Potomac River- A. maritima was collected at Point Lookout MD, at the river mouth in 1924 (U. S. Museum of Natural History collections). Many specimens were found under logs at Chapel Point State Park MD, just north of the US 301 bridge, adjacent to mesohaline waters, but so far this species has not been found in the fresh-oligohaline zone, to our knowledge (Fofonoff, unpublished data).
Upper Bay - It was collected in brackish tidal marsh near the southern end of Kent Island, Queen Anne's County MD (Bickley and Seek 1975). At Shady Side MD, along the Rhode River, Edgewater MD, and at North Point State Park (Edgemere MD, north of Baltimore) A. maritimus are found under logs and rip-rap stones at the flood-tide line (Fofonoff, unpublished data).
History References - Bennett 1904; Bickley and Seek 1975; Carlton 1979; Cohen and Carlton 1995; Hincks 1947; Langston 1974; Morse 1920; Rehn and Hebard 1916; Rehn and Hebard 1917; Scudder 1876a; Scudder 1876b; U. S. Museum of Natural History collections; Vickery and Kevan 1985
Invasion Comments
Residency- This insect occurs most regularly in high intertidal and supratidal habitats of estuaries and seashores, though it has been collected in mountain regions far from the sea (Hincks 1954). It shows numerous behavioral adaptations to a littoral habitat and tolerates submersion for at least an hour (Bennett 1904).
Native Region, Source Region - The origin of this insect is somewhat uncertain, because this species was probably transported widely by shipping before its description (Hincks 1947). The Mediterranean region, from which it was described, seems a likely choice.
Probable, Alternate Vectors into Chesapeake Bay, North America - Transport with dry ballast seems likeliest, but these earwigs are likely to be transported with cargo, or to invade ships from docks and piers. Anisolabis maritima has also been found in inspections of plants (Chrysanthemums, Dahlias, Araucaria) shipped into CA (Langston 1974).
Ecology
Environmental Tolerances
| For Survival | For Reproduction | |||
|---|---|---|---|---|
| Minimum | Maximum | Minimum | Maximum | |
| Temperature (ºC) | ||||
| Salinity (‰) | 0.0 | |||
| Oxygen | ||||
| pH | ||||
| Salinity Range | meso-eu |
Age and Growth
| Male | Female | |
|---|---|---|
| Minimum Adult Size (mm) | 18.0 | 15.5 |
| Typical Adult Size (mm) | 20.8 | 20.0 |
| Maximum Adult Size (mm) | 23.5 | 25.5 |
| Maximum Longevity (yrs) | 2.0 | 2.0 |
| Typical Longevity (yrs | 1.0 | 1.0 |
Reproduction
| Start | Peak | End | |
|---|---|---|---|
| Reproductive Season | |||
| Typical Number of Young Per Reproductive Event |
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| Sexuality Mode(s) | |||
| Mode(s) of Asexual Reproduction |
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| Fertilization Type(s) | |||
| More than One Reproduction Event per Year |
|||
| Reproductive Startegy | |||
| Egg/Seed Form |
Impacts
Economic Impacts in Chesapeake Bay
Anisolabis maritima (Seaside Earwig) has no known economic impacts in the Chesapeake Bay region.
Economic Impacts Outside of Chesapeake Bay
Economic impacts of Anisolabis maritima (Seaside Earwig's) have not been noted. Since drift debris is often a source of annoying fly populations, this carnivorous species could be regarded as potentially beneficial. On the other hand, its 'unattractive coloring and sinuous crawling movements usually produce a feeling of repugnance in the observer' (Morse 1920).
References- Morse 1920
Ecological Impacts on Chesapeake Native Species
Anisolabis maritima's (Seaside Earwig's) impacts on littoral communities in Chesapeake Bay and elsewhere have not been studied, and are unknown. This earwig is a predator and scavenger in the strandline community (Bennett 1904; Langston 1974; Vickery and Kevan 1985).
References- Bennett 1904; Langston 1974; Vickery and Kevan 1985
Ecological Impacts on Other Chesapeake Non-Native Species
Among introduced and cryptogenic species Anisolabis maritima's( Seaside Earwig's) habitat in Chesapeake Bay and elsewhere are the isopod Ligia exotica and the polychaete Namanereis littoralis. Interactions of the earwig with these animals have not been studied.
References
Bennett, Charles B. (1904) Earwigs (Anisolabis maritima Bon.), Psyche 11: 47-53Bickley, William E.; Seek, Timothy R. (1975) Insects in four Maryland marshes., Agricultural Experiment Station University of Maryland, College Park, Maryland: Miscellaneous Publications 870: 1-27
Blatchley, W. S. (1920) Orthoptera of Northeastern America, In: (Eds.) . , Indianapolis. Pp.
Carlton, James T. (1979) History, biogeography, and ecology of the introduced marine and estuarine invertebrates of the Pacific Coast of North America, , Davis. Pp. 1-904
Cohen, Andrew N.; Carlton, James T. (1995) Nonindigenous aquatic species in a United States estuary: a case study of the biological invasions of the San Francisco Bay and Delta, , Washington DC, Silver Spring MD.. Pp.
Hincks, W. D. (1947) Preliminary notes on Mauritian Earwigs (Dermaptera), Annals and Magazine of Natural History : 518-540
Langston, Robert L. (1974) The maritime earwig in California (Dermaptera: Carcinophoridae), Pan-Pacific Entomologist 50: 28-34
Morse, Albert P. (1920) Manual of the Orthoptera of New England, Proceedings of the Boston Society of Natural History 35: 197-556
Rehn, James A. G.; Hebard, Morgan (1916) Studies in the Dermaptera and Orthoptera of the Coastal Plain and Piedmont region of the southeastern United States, Proceedings of the Academy of Natural Sciences of Philadelphia 68: 87-314
Rehn, James A. G.; Hebard, Morgan (1917) Studies in West Indian Earwigs (Dermaptera), Bulletin of the American Museum of Natural History 37: 635-651
Scudder, Samuel H. (1876) Critical and historical notes on Forficulariae, including descriptions of new generic forms and an alphanumeric synonymic list of the described species., Proceedings of the Boston Society of Natural History 18: 287-332
Scudder, Samuel H. (1876) A synopsis of North American earwigs, with an appendix on the fossil species, Bulletin of the United States Geological Survey 2: 249-260
Vickery, Vernon R.; Kevan, D. K. M. (1985) The Insects and Arachnids of Canada and Adjacent Regions: Part 14: The Grasshoppers, Crickets, and Related Insects of Canada and Adjacent Regions. Ulonata: Dermaptera, Cheleutoptera, Notoptera, Dictyoptera, Grylloptera and Orthoptera, , Ottawa. Pp.