NEARCTIC REGION
Etymology: not stated [poss. scale bearer (L)]
The coastal species Ae. squamiger has a very restricted distribution, found only on the west coast of the United States—as far north as Bodega Bay in Sonoma County, California—and in Baja California, Mexico. Thought to be most closely related to the high mountain snowmelt mosquito, Aedes hexodontus Dyar, Ae. squamiger remains unplaced within the subgenus Ochlerotatus. It has one synonym—deniedmannii Ludlow—described from Benicia, California, United States.
Type locality: Palo Alto, California, United States
Type depository: U.S. National Museum, Washington D.C., United States (USNM)
DIAGNOSTIC CHARACTERS (Click photos to view; mouse over and click large photo to zoom in.)
ADULT (illustrated): Head: Proboscis with many dark and pale scales intermixed, without median pale band; Ta-III1–5 with broad, only basal pale bands; pale band on Ta-III2 less than one third of segment. Thorax: Scutum with mixed brown and pale scales laterally; postpronotum without contrastingly-colored scale patches. Wing: With broad triangular-shaped, dark and pale scales evenly intermixed; mixed black and white tertiary fringe scales. Abdomen: Terga with basal pale bands.
LARVA (not illustrated): Head: Antenna spiculate; seta 1-A multi-branched; seta 5-C 1–4 branched; seta 6-C usually single or double. Terminal segments: Comb scales fringed with subequal spinules; seta 1-X as long or longer than Sa; saddle incomplete; siphon with 1 pair of setae, excluding seta 2-S.
TAXONOMIC KEYS
Gjullin 1937
Freeborn & Bohart 1951
Yamaguiti 1952
Carpenter & LaCasse 1955
Dodge 1966
Myers 1967
Bohart & Washino 1978
Bohart & Washino 1978
Darsie & Ward 2005
Exemplar DNA sequences
Ae. squamiger COI: JX259673–75
BIONOMICS
Immatures
Aedes squamiger is a coastal floodwater mosquito that is common in salt marshes within its restricted range. However, construction sites—such as housing developments, roads, and railroads—also provide suitable habitat where salt marshes are scarce. The species overwinters as drought-resistant eggs in parts of the salt marsh protected from strong tidal flow, but flooded by the combination of high tides and rain that occur in this region in the winter. In the northern part of its range (where it is most abundant), neonates emerge in early winter when water temperatures dip below about 10°C, and larval development continues slowly through the winter in the cold, highly oxygenated water.
Adults
Diapause is interrupted in April, following the temperature rise and early spring rains, and adults emerge in huge cohorts and immediately mate. After copulation, the females can travel dozens of kilometers inland in search of blood meals. As a result of these attributes, the species is a locally significant human pest in California in spring time, yet the species is not frequently collected in in CO2-baited EVS traps.
DISTRIBUTION NOTES
Mexico, United States (continental).
WRBU VECTOR HAZARD REPORTS
None; View other WRBU Vector Hazard Reports
Available GIS Models:
None
IMPORTANT REFERENCES (full citations below)
Coquillett 1902c: 85 (F; as Culex)
Howard et al. 1917 (E*)
Gjullin 1937: 258 (F; key)
Bohart 1948: 216 (P*, L*)
Yamaguti & LaCasse 1951d: 184 (M*, F*, L*)
Freeborn & Bohart 1951 (M*, F, L; keys, bionomics)
Yamaguti 1952 (M*, F; keys)
Bohart 1954: 364 (1st instar L*)
Carpenter & LaCasse 1955: 231 (M*, F*, L*; keys)
Craig 1956 (E*)
Stone & Knight 1956a: 225 (type info., lectotype designation)
Dodge 1966: 357 (1st instar L; key)
Myers 1967: 798 (E*; key; California, Nevada)
Mohrig 1967 (F*)
Bohart & Washino 1978 (M, F*, L*; keys, bionomics, taxonomy)
Bohart & Washino 1978: 116 (M, F*, L*; keys, taxonomy, bionomics, distribution)
Darsie & Ward 2005 (F*, L*; keys, distribution)
Darsie 2011a (P*)
CURRENT SYNONYMS
syn. deniedmannii Ludlow
1904b: 234 (F; Grabhamia). Type locality: Benicia, California, United States (USNM). References: Stone & Knight 1956a: 217 (type information, lectotype designation).
CITED REFERENCES
Bohart, R.M. (1948). Differentiation of larvae and pupae of Aedes dorsalis and Aedes squamiger (Diptera, Culicidae). Proceedings of the Entomological Society of Washington, 50(8), 216–218.
Bohart, R.M. (1949). The subgenus Neoculex in America North of Mexico (Diptera, Culicidae). Annals of the Entomological Society of America, 41(1948), 330–345.
Bohart, R.M. (1954). Identification of first stage larvae of California Aedes (Diptera, Culicidae). Annals of the Entomological Society of America, 47(2), 355–366.
Bohart, R.M. & Washino, R.K. (1978). Mosquitoes of California (3rd ed.). Berkeley, CA: University of California, Agriculture and Natural Resources.
Carpenter, S.J., & LaCasse, W.J. (1955). Mosquitoes of North America (North of Mexico). Berkeley, Los Angeles: University of California Press.
Coquillett, D.W. (1902c). New Diptera from North America. Proceedings of the United States National Museum, 25, 83–126.
Craig Jr., G.B. (1956). Classification of eggs of nearctic Aedinae mosquitoes (Diptera: Culicidae). Dissertation Abstract (5).
Darsie, R.F., Jr. (2011a). Redescription of the pupae of Ochlerotatus dorsalis and Ochlerotatus squamiger. Journal of the American Mosquito Control Association, 27(2), 105-15–110.
Darsie, R.F., Jr., & Ward, R.A. (2005). Identification and geographical distribution of the mosquitoes of North America, north of Mexico. Gainesville, FL: University Press of Florida.
Dodge, H. R. (1966). Studies on mosquito larvae II. The first-stage larvae of North American Culicidae and of world Anophelinae. Canadian Entomologist, 98, 337–393.
Freeborn, S.B., & Bohart, R.M. (1951). The mosquitoes of California. Bulletin of the California Insect Survey, 1(2), 25–78.
Gjullin, C.M. (1937). The female genitalia of the Aedes mosquitoes of the Pacific coast states. Proceedings of the Entomological Society of Washington, 39, 252–266.
Horsfall, W.R., & Craig, G.B. Jr. (1956). Eggs of floodwater mosquitoes IV. Species of Aedes common in Illinois. (Diptera: Culicidae). Annals of the Entomological Society of America, 49(4), 368–374.
Howard, L.O., Dyar, H.G., & Knab, F. (1917). The mosquitoes of North and Central America and the West Indies. Systematic description. Part II. Carnegie Institute of Washington.
Ludlow, C.S. (1904b). Mosquito notes. Canadian Entomologist, 36, 233–236.
Mohrig, W. (1967). Die taxonomische Bedeutung der Struktur weiblicher Genitalien im Culiciden- Tribus Aedini. Angewandte Parasitologie, 8, 67–100.
Myers, C.M. (1967). Identification and description of Aedes eggs from California and Nevada (Diptera: Culicidae). Canadian Entomologist, 99, 795–806.
Stone, A., & Knight, K.L. (1956a). Type specimens of mosquitoes in the United States National Museum. II. The genus Aedes (Diptera, Culicidae). Journal of the Washington Academy of Sciences, 46(7), 213–228.
Yamaguti, S. (1952). Illustrated keys to the adult culicine mosquitoes of America north of Mexico with notes on general morphology and biology of genera. Published by the author, 48 pp.
Yamaguti, S., & LaCasse, W.J. (1951d). Mosquito fauna of North America. Part V – Genus Aedes. Office of the Surgeon, Headquarters, 8th Army, APO 343. United States. Office of the Surgeon-General. 207th Malaria Survey Detachment.
CITE THIS PAGE
Walter Reed Biosystematics Unit (Year). Aedes squamiger species page. Walter Reed Biosystematics Unit Website, http://wrbu.si.edu/vectorspecies/mosquitoes/squamiger, accessed on [date (e.g. 03 February 2020) when you last viewed the site].
