Dascillus davidsoni LeConte, 1859

Johnston, M. Andrew & Gimmel, Matthew L., 2020, Review of North American Dascillidae (Coleoptera: Dascilloidea), with Descriptions of Dramatic Female Wing Reduction, The Coleopterists Bulletin 74 (4), pp. 731-757 : 745-749

Dascillus davidsoni LeConte, 1859

( Figs. 9–11 )

Dascyllus Davidsonii LeConte 1859b: 283 . Type locality: Punto de los Reyes [= Point Reyes], Marin County, California.

Dascyllus Davidsoni : Horn 1880: 84. Subsequent spelling in prevailing usage.

Dascyllus plumbeus Horn 1880: 84 . New Synonym. Type locality: Mariposa district , California.

Diagnosis. By far the largest and most robust dascillid species in North America, D. davidsoni ( Figs. 9–11 ) can easily be recognized by its size ( 10 mm or greater in total length), robust overall body shape, and the wide prosternal process separating the procoxal cavities externally and reaching their posterior margin (coxae contiguous in Anorus species).

Redescription of Male. Body parallel-sided, 10–18 mm ( Fig. 9 ). Body setae variable, recumbent, never bristling. Antennomeres 3–10 serrate, subtriangular. Left mandible with one distinct, blunt retinaculum and a second weak and very blunt retinaculum apicad. Right mandible with single retinaculum. Epicranial suture indistinct but traceable. Lateral sides of pronotum explanate, dorsal and ventral surfaces well demarcated by complete lateral carina, posterior margin strongly bisinuate; pronotum evenly narrowing from base to apex. Prosternal process relatively large, distinctly surpassing posterior margin of procoxae; mesoventrite with anteriorly projected prosternal rest (boatshaped cavity to accept prosternal process), bearing distinct procoxal rests. Hypomeron with distinct angulate postcoxal process. Elytra weakly punctatestriate, striae becoming slightly impressed posteriorly. Hind wing about 2.5 times longer than greatest width, attaining apex of abdomen; radial cell completely closed proximally; wedge cell large, separated from posterior edge by distance less than half length of cell; apical field about one-fourth length of wing. All tibiae lacking stout spinules along outer margin. All legs with tarsomeres 1–4 bearing fleshy bilobed pads beneath. Terminalia with tergite IX ( Fig. 10C ) with broad V-shaped emargination along posterior margin; tergite X ( Fig. 10C ) evenly rounded apically; sternite IX ( Fig. 10B ) rounded apically; phallobase of aedeagus ( Figs. 10A, D–G ) weakly emarginate basally, slightly broader than long; parameres longer than phallobase, narrowing from base to apex, lateral margin straight until recurved laterally near apex, bearing scattered long setae laterally in apical half; dorsal lobe of penis measured from anterior margin of basal strut to posterior apex approximately as long as paramere, elongate triangular, apex weakly to broadly rounded and weakly sclerotized medially, sometimes appearing cleft; ventral lobe of penis distinctly shorter than dorsal lobe, triangular, evenly tapering to apex, curved ventrally near apex, apex truncate to slightly emarginate.

Redescription of Female. Similar to male except: Larger, body stouter ( Fig. 11A ), widest in apical half of elytra. Epicranial suture very distinct and sulcate. Hind wing slightly narrower than in male, about 2.6 times longer than greatest width but attaining apex of abdomen. Terminalia ( Figs. 11B, C ) with tergite IX distinctly broadly emarginate along anterior margin; sternite VIII (spiculum ventrale) narrowly triangular; proctiger narrowly triangular; paraprocts relatively short, with ventral baculi converging apically; gonocoxites subequal in length to paraprocts, each coxite with proximal lobe heavily sclerotized ventrally, triangularly produced medially; gonostyli absent.

Note on Synonymy and Variation. After examination of 630 specimens of North American Dascillus, we concluded that the two traditionally recognized names refer to expressions of conspecific color morphs. The traditional concept of D. davidsoni, here referred to as the “davidsoni-morph” ( Fig. 9A ), refers to specimens with a lighter reddish-brown cuticle with pale setae forming a dark double zig-zag across the elytra. The traditional concept of D. plumbeus , here referred to as the “plumbeus- morph” ( Fig. 9B ), includes specimens without a zig-zag pattern, only rows of pale to dark setae on the elytral interstriae, often giving a pinstriped appearance. Additionally, the cuticle of the elytra in the latter tends to be darker, piceous to nearly black, although dark or light reddish-brown cuticle can occur along with either setal pattern (e.g., Figs. 9C, D ). Consequently, abraded individuals are nearly impossible to definitively assign to morph. On the other hand, particular morphs tend not to be mixed at a given locality, and there are very few individuals that are intermediate, i.e., that express a faint zig-zag pattern. Regions that include predominantly plumbeus- morph include the Sierra Nevada foothills and the interior Coast Range north of San Francisco Bay, while the davidsoni- morph dominates the southern and western sides of the San Francisco Bay and the Pacific slopes of the Coast Ranges. Localities from which we have seen both morphs include Martinez (Contra Costa Co.), Mill Valley (Marin Co.), Hopland (Mendocino Co.), Mount Saint Helena (Napa Co.), Mount Hamilton (Santa Clara Co.), and Sylvania (county unknown), while faint-patterned intermediate individuals were prevalent along a transition zone in the central portion of the northern Coast Ranges, including Fort Seward (Humboldt Co.) and Clearlake Oaks (Lake Co.).

In addition to variation in color pattern, the last abdominal ventrite (ventrite 5) in the male is variably emarginate at the apex, but this is not observably correlated with other variation. Horn (1880), in the original description of D. plumbeus , used the relative lengths of antennomeres 3 and 4 to separate the two Dascillus species, but we were unable to make use of this character across our larger sampling of specimens and localities.

Such synonymy and individual variation is not without precedent in the genus Dascillus. Terzani et al. (2017) published on the widespread, variable species D. cervinus of the Western Palearctic region. They observed variation in the coloration of both the integument and setation, the shape of abdominal sternite IX, and even among structures of the aedeagus, such as the ventral lobe of the penis, which ranged from parallel-sided to narrowing, and the dorsal lobe of the penis, which ranged from indistinctly to distinctly projecting medially (see Terzani et al. 2017: fig. 2). Additionally, apparent variation in the shape of the parameres should be interpreted with caution; these structures are flexible and highly sensitive to distortion resulting from mounting medium, level of clearing, and from the amount of extrusion of the penis. The very limited genitalic variation ( Figs. 10A, D–G ) seen in D. davidsoni as circumscribed herein falls well within the magnitude of intraspecific variability observed within certain Old World Dascillus species concepts.

Distribution. Central California north to Humboldt County, south to Santa Barbara County, and west to the western foothills of the Sierra Nevada ( Fig. 12 ). Specimen records from Arizona, Oregon, and Mexico (see below) seem to be erroneous, although its occurrence in southwestern Oregon would not be unexpected.

Note on Type Material and Spelling. LeConte (1859b) did not mention how many specimens he used for the original description of D. davidsoni, but there must have been at least two since he compared male and female characters. However, Horn (1880: 84) stated “The female of Davidsoni is unknown to us”, implying that LeConte mistook one or more of his male specimens for a female. Our examination of photographs of specimens in the LeConte collection (MCZ) revealed 11 specimens, all male; these 11 should probably be considered syntypes.

Horn (1880) did not mention how many specimens he used for the original description of D. plumbeus , but there must have been at least two since he compared male and female characters. Examination of photographs of specimens labeled as this species in the LeConte and Horn collections (MCZ) revealed eight specimens, including six males and two (probable) females; these eight should probably be considered syntypes. One specimen is labeled “ lectotype ”, but this designation has never been published. For this species, Horn apparently observed genuine females, describing them as much larger ( 20 mm) and more robust, having the last ventrite slightly shorter, and the flight wings less developed than those of the male and “probably unsuitable for flight.” Two large specimens of plumbeus- morph from the Horn collection in the MCZ appear to be females.

The subsequent spelling Dascillus davidsoni LeConte is in prevailing usage ( Horn 1880; Jin et al. 2013b; Leng 1920; O’ Keefe 2002) and should be maintained ( ICZN 1999: Art. 33.3.1).

Specimens Examined (630). NOTE: The various morphs of this species are indicated by letters in square brackets after the numbers of specimens (d = davidsoni- morph; p = plumbeus- morph; i = intermediate). UNITED STATES: CALIFORNIA: Alameda Co.: Alameda , 22 May 1932, E. S. Ross ( 1♂ [d], CASC); Albany Hill, 16 April 1998, Robert L. Langston ( 1♂ [d], CASC); Berkeley, 13 May 1917, R. Hopping collection ( 1♂ [d], CASC); Berkeley, 25 April 1921, J. O. Martin ( 1♂ [d], CASC); Berkeley, 26 April 1924, F. C. Hadden ( 1♂ [d], LACM); Berkeley, April 1925, R. M. and G. E. Bohart ( 1♂ [d], CASC); Berkeley, February 1932 ( 1♀ [d], LACM); Berkeley, 8 May 1938, J. G. Shanafelt ( 1♂ [d], LACM); Berkeley, 24 April 1948, D. W. Buddy ( 1♂ [d], CASC); Berkeley, 16 May 1949, R. S. Beal ( 1♂ [d], ASUHIC); CSCH Campus, Hayward, 17 May 1967, Kenneth France ( 1♂ [d], CASC); “Dimond G.”, 14 May 1900, F. E. Blaisdell ( 1♂ [d], CASC); Hayward, May 1911 ( 2♂♂ [d], LACM); hills back of Oakland, 19 April 1919, Van Dyke collection ( 5♂♂ [d], CASC); Livermore, 11 May 1930, Van Dyke collection ( 1♂ [d], CASC); Mills College, 19 April 1926, Thos. Craig ( 1♂ [d], CASC); Niles, 14 April 1914, E. J. Branagan ( 1♂ [d], UCRC); Niles, 19 April 1914, Blaisdell collection ( 1♂ [d], CASC); Niles Canyon, 23 May 1917, W. M. Gifford ( 1♂ [d], CASC); Oakland, Van Dyke collection ( 2♂♂ [d], CASC); Oakland, April 1901, Van Dyke ( 8♂♂ [d], CASC); Oakland, 10 April 1925, F. C. Hadden ( 1♂ [d], LACM); Oakland, 18 April 1931, E. S. Ross ( 1♂ [d], CASC); same except 21 May 1932 ( 1♂ [d], CASC); Oakland, May 1982, F. R. Barnes ( 1♂ [d], CASC); Oakland, E. J. Blum ( 2♂♂ [d], CASC); Oakland Hills, 18 April 1926, Van Dyke collection ( 4♂♂ [d], CASC); Oakland Hills, 12 April 1940, J. J. Marquis ( 5♂♂ [d], CASC); Pleasanton, 23 April 1939, G. S. Mansfield ( 1♂ [d], CASC); San Leandro, Elsie Avenue, 5 May 1983, Thomas W. Davies ( 1♂ [d], CASC); Strawberry Canyon, 29 April 1956, C. L. Hogue ( 2♂♂ [d], LACM); Sunol, 14 May 1922, F. E. Blaisdell ( 1♂ [d], CASC); Sunol Valley Regional Park, 9 May 1964, W. K. Fox ( 1♂ [d], ASUHIC); Sunol Valley Regional Park, 10 May 1967, V. Lee ( 1♂ [d], CASC); Tunnel Road, 13 May 1917, W. M. Giffard ( 1♂ [d], CASC); [county record only], Van Dyke collection ( 3♂♂ [d], CASC); [county record only], R. Hopping collection ( 4♂♂ [d], CASC); [county record only], April, Koebele collection ( 1♂ [d], CASC); [county record only], Leng, R. Hopping collection ( 1♀ [d], CASC); [county record only], Blaisdell collection ( 1♀ [d], CASC); [county record only] ( 1♀ [d], CASC); Butte Co. : Oroville, 9 April 1928, H. H. Keifer ( 2♂♂ [p], CASC); Oroville, 30 April 1971 ( 5♂♂ [p], UCRC); Oroville, 2 May 1971 ( 4♂♂ [p], UCRC); Calaveras Co. : Mokelumne Hill, Blaisdell collection ( 15♂♂ [p], CASC); same except 3 May 1893 ( 1♂ [p], CASC); same except 11 May 1893 ( 4♂♂ [p], CASC); Mokelumne Hill, 20 May 1942, F. E. Blaisdell ( 1♂ [p], CASC); Colusa Co. : [county record only], 20 May 1951, M. Marquis ( 1♂ [d], CASC); Contra Costa Co. : Concord, 26 April 1942, H. P. Chandler ( 3♂♂ [d], CASC); Danville, 8 April 1962, R. Brown ( 1♂ [d], CASC); same except 14 May 1962 ( 1♂ [d], CASC); Lafayette, 10 May 1947, T. W. Fisher ( 1♂ [d], UCRC); Lafayette, 22 May 1951 ( 2♂♂ [d], CASC); Martinez, 21 April 1909, Van Dyke collection ( 1♂ [d], CASC); same except April 1910 ( 1♀ [d], CASC); same except June 1910, Van Dyke collection ( 1♂ [p], CASC); Moraga Ranch, 7 May 2009, S. E. Haskins ( 1♂ [d], MAJC); Mount Diablo , 21 June 1931 ( 4♂♂ [d], LACM); Mount Diablo , 24 April 1927, B. E. White ( 1♂ [d], CASC); Mount Diablo , 24 April 1932, O. Bryant ( 4♂♂ [d], CASC); Mount Diablo , base, 28 April 1932, O. Bryant ( 1♂ [d], CASC); Mount Diablo , 30 April 1933, E. S. Ross ( 1♂ [d], CASC); Mount Diablo , 21 May 1937 ( 1♂ [d], CASC); Mount Diablo , 18 May 1951 ( 2♂♂ [d], CASC); Mount Diablo , northeast slope of North Peak , 30 April 1967, R. M. Brown ( 1♂ [d], CASC); Russelmann Park, east slope of Mount Diablo , 19 April 1931, E. P. Van Duzee ( 1♂ [d], CASC); Russelmann Park, Mount Diablo , 17 May 1960, D. C. Rentz ( 1♂ [d], CASC); Russelmann Park, Mount Diablo , 24 April 1966, R. M. Brown ( 11♂♂ [d], CASC); Russelmann Park, 2 miles SE Clayton, 1,200 ft, 20 May 1967, Paul H. Arnaud, Jr. ( 1♂ [d], CASC); Russelmann Park, 20 May 1967, J. W. Tilden ( 1♂ [d], CASC); Walnut Creek , Castle Rock Park, 10 May 1975, Harvey I. Scudder ( 1♂ [d], CASC); [county record only], 20 July 1911, F. W. Nunenmacher ( 1♂ [d], CASC); El Dorado Co. : Camino, 12 May 1979, D. Plubell ( 1♂ [p], CASC); Coloma, 260 m, hillside, under oaks, 24 May 1981, Paul H. Arnaud, Jr. ( 1♂ [p], CASC); Diamond Springs, 15 May 1954, Truxal and Martin ( 1♂ [p], LACM); Pine Hill, west of Rescue , 1,5000, 2 May 1970, D. P. Levin ( 2♂♂ [p], LACM); Humboldt Co. : Blocksburg, 21 May 1933, Brunson P. Bliven collection ( 1♂ [d], CASC); same except 8 April 1934 ( 2♂♂ [d], CASC); Blocksburg, 25 May 1935, H. J. Rayner ( 1♂ [d], CASC); Blocksburg, 19 April 1936, B. P. Bliven ( 2♂♂ [d], CASC); same except 3 May 1936 ( 1♂ [d], CASC); Benbow, 23 April 1941, B. P. Bliven ( 1♂ [d], CASC); Eureka, 3 June 1935, E. O. Essig ( 1♂ [p], CASC); Fort Seward , 21 May 1935, F. R. Platt ( 1♂ [d], LACM; 1♂ [d], UCRC); Fort Seward , 18 May 1935, E. O. Essig ( 1♂ [i], CASC); same except 5 June 1935 ( 1♀ [i], CASC); same except 20 May 1935, H. J. Rayner ( 2♂♂ [i], CASC); same except 24 May 1935 ( 2♂♂ [i], CASC); same except 28 May 1935 ( 1♂ [i], CASC); Fort Seward , 23 May 1935, E. W. Baker ( 1♂ [i], CASC); Fort Seward , 25 May 1935, E. O. Essig ( 1♂ [i], CASC); same except 25 May 1935 ( 1♂ [i], CASC); Garberville, 28 April 1940, B. P. Bliven ( 2♂♂ [d], CASC); Korbel, 5 June 1916, F. E. Blaisdell ( 1♂ [d], CASC); Miranda, 25 April 1937, B. P. Bliven ( 1♂ [p], CASC); Lake Co. : 8 miles north of Kelseyville , 11 May 1952, sweeping, F. B. Turner ( 1♂ [p], LACM); Anderson Springs, 20 May 1951, W. R. Bauer ( 1♂ [p], CASC); same except 17 May 1952 ( 1♂ [p], CASC); Blue Lakes, 16 May 1922, E. P. Van Duzee ( 1♂ [p], CASC); Clearlake Oaks, 19 May 1951, Don Burdick ( 1♂ [i], CASC); Clearlake Oaks, 20 May 1951, J. W. Tilden ( 1♂ [i], CASC); Lower Lake , 13 May 1922, E. P. Van Duzee ( 2♂♂ [p], CASC); Snow Mountain , 22 May 1971, J. Kraemer ( 1♂ [p], CASC); Soda Bay Springs, Kelseyville, 15 May 1922, E. P. Van Duzee ( 1♂ [p], CASC); Upper Lake , 17 May 1922, E. P. Van Duzee ( 1♂ [d], CASC); [county record only], May 1895, Van Dyke collection ( 11♂♂ [p], CASC); [county record only], Van Dyke collection ( 5♂♂ [p], CASC); Marin Co. : Cypress Ridge, 27 April 1920, J. O. Martin ( 1♂ [d], CASC); Fairfax, 11 May 1919, E. P. Van Duzee ( 4♂♂ [d], CASC); same except 9 May 1920 ( 1♂ [d], CASC); same except 4 May 1928 ( 1♂ [d], CASC); Fairfax, 12 April 1925, C. L. Fox ( 1♂ [d], CASC); Fairfax, 1 May 1949, W. A. Russell ( 1♂ [d], CASC); Lagunitas, 11 May 1924, E. P. Van Duzee ( 1♂ [d], CASC); Lake Lagunitas , 29 May 1959, D. C. Rentz ( 1♂ [d], CASC); Mill Valley , 28 April 1913, R. Hopping collection ( 2♂♂ [d], CASC); same except 10 May 1914 ( 1♂ [d], CASC); same except 22 April 1915 ( 1♂ [d], CASC); Mill Valley , 15 May 1948, Frances O. Leech ( 1♀ [d], CASC); same except 24 May 1948 ( 1♂ [d], CASC); Mill Valley , 25 May 1948, H. B. Leech ( 1♂ [d], CASC); same except 1 June 1948 ( 1♂ [d], CASC); same except 7 June 1948 ( 1♂ [d], CASC); same except 16 May 1949 ( 1♂ [d], CASC); same except 22 May 1949 ( 2♂♂ [d], CASC); Mill Valley , June 1948, E. S. Ross ( 1♀ [d], CASC); Mill Valley , 9 May 1950, W. H. Leech ( 1♂ [d], CASC); Mill Valley , 16 May 1959, J. L. Bath ( 1♂ [p], UCRC); Mill Valley , 26 April 1965, P. H. Arnaud, Jr. ( 1♂ [d], CASC); same except 2–4 May 1965 ( 1♂ [d], CASC); same except 6–10 May 1965 ( 2♂♂ [d], CASC); Mill Valley , 5 May 1965, Loyal Weitz ( 1♂ [d], CASC); Mill Valley , chaparral zone, May 1980, E. S. Ross ( 1♀ [d], CASC); Mount Tamalpais , 28 April 1907, Blaisdell collection ( 2♂♂ [d], CASC); Mount Tamalpais , Old Stage Road, at flower of blue flowering Lupinus, 22 May 1999, Paul H. Arnaud, Jr. ( 1♂ [d], CASC); Muir Woods, 21 April 1921, J. O. Martin ( 1♂ [d], CASC); Novato, 23 April 1961, D. C. Rentz ( 1♂ [d], CASC); Paradise Cove, 6 May 1951, J. W. Green ( 1♂ [d], CASC); Phoenix Lake vicinity, 3 May 1962, D. C. Rentz ( 1♂ [d], CASC); Ross, 28 April 1918, E. P. Van Duzee ( 1♂ [d], CASC); Ross, 9 April 1939, B. E. White ( 1♂ [d], CASC); Samuel P. Taylor State Park , along Lagunitas Creek , 18 May 1977, D. D. Wilder ( 2♂♂ [d], CASC); [county record only], April, Blaisdell collection ( 2♂♂ [d], CASC); between Alp. [illegible], 18 May 1958, D. C. Rentz ( 1♂ [d], CASC); [county record only], Bolter collection ( 2♂♂ [d], INHS); Mariposa Co. : Jerseydale, 8 miles northeast of Mariposa , 3,5000, 14 May 1974, Oakley Shields ( 1♂ [p], LACM); Mendocino Co. : Hopland, 9 May 1926, E. P. Van Duzee ( 2♂♂ [d], CASC); Hopland Experimental Station , ¼ mile southwest of Poor Ranch , 28 April 1972, E. Rogers ( 2♂♂ [p], CASC); Hopland Field Station , Kelsey Cab. Orchard area , 2,500–2,800 ft, 14 May 1977, R. Greenberg ( 1♂ [p], CASC); same except M. P. Pavel ( 1♂ [p], CASC); Hopland Field Station , Headquarters Lake , 900–1600 ft, 15 May 1977, M. P. Pavel ( 1♂ [p], CASC); same except N. J. Vandenberg ( 1♂ [p], CASC); Orrs Springs, 7 May 1936, Van Dyke collection ( 1♂ [d], CASC); Philo, 13 May 1933 ( 1♂ [d], CASC); Philo, 14 May 1933, J. W. Tilden ( 1♂ [d], CASC); same except 20 May 1938 ( 2♂♂ [d], CASC); Ukiah Grade, 10 May 1926, E. P. Van Duzee ( 1♂ [p], CASC); Yorkville, 17 May 1929, E. P. Van Duzee ( 3♂♂ [d], CASC); same except 8 May 1935 ( 1♂ [d], CASC); Monterey Co. : Arroyo Seco, 10 May 1969, J. W. Tilden ( 1♂ [d], CASC); Arroyo Seco, 14 May 1994, J. G. Edwards ( 1♂ [d], CASC); Bradley, 28 April 1955, R. P. Allen ( 4♂♂ [d], CASC); Lockwood, 3 April 1957, R. P. Allen ( 20♂♂ [d], CASC); same except 25 April 1958 ( 6♂♂ [d], CASC); Paraiso Springs, 3 May 1922, L. S. Slevin collection ( 1♂ [d], CASC); same except 4 May 1922 ( 3♂♂ [d], CASC); same except 5 May 1922 ( 1♂ [d], CASC); Napa Co. : 2 miles north-northeast of Angwin, north side of Howell mountain , 1,300 ft, 25 April 1976, H. B. Leech ( 1♂ [p], CASC); same except 2 May 1976 ( 1♂ [p], CASC); same except 4 May 1976 ( 1♂ [p], CASC); same except 26 April 1979 ( 1♂ [p], CASC); same except 3 May 1979 ( 1♂ [p], CASC); same except 11 May 1979 ( 1♂ [p], CASC); same except 24 April 1980 ( 1♂ [p], CASC); same except 2 May 1980 ( 1♂ [p], CASC); same except 6 May 1980 ( 1♂ [p], CASC); same except 7 May 1980 ( 1♂ [p], CASC); same except 7 May 1981 ( 2♂♂ [p], CASC); same except 29 April 1982 ( 1♀ [p], CASC); same except 4 May 1984 ( 1♂ [p], CASC); same except 18 May 1976, F. O. Leech ( 1♂ [p], UCRC); same except “adult died” 15 March 1982, “reared from 45 mm long larva ex garden soil, 7.III.1981; pupated Sept. 1981, adult emerged 28.X.1981 ” ( 1♀ [p], CASC); same except “ 18.III.1981 as larva in soil” and “found in garden soil, 12 inches below surface; reared; as adult in soil, late October 1981, died 3.I.1982 ” ( 1♂ [p], CASC); Angwin, 16 May 1957, Laurell Rouse ( 1♂ [p], CASC); same except 25 May 1957 ( 1♂ [p], CASC); same except 23 May 1959 ( 1♂ [p], CASC); Angwin, 16 May 1958, Elizabeth McCart ( 2♂♂ [p], CASC); Angwin, 9 May 1960, Marilyn Brandt ( 1♂ [p], CASC); Angwin, 20 May 1961, [collector illegible] ( 1♂ [p], CASC); Angwin, 2 May 1962, B. Easterbrook ( 1♂ [p], CASC); Angwin, 18 May 1971, T. Griswold ( 1♂ [p], CASC); Angwin, 25 May 1972, G. Miller ( 1♂ [p], CASC); Angwin, 10 May 1972 ( 1♂ [p], CASC); Angwin, 30 May 1972 ( 1♂ [p], CASC); Angwin, 6 May 1977 ( 1♂ [p], CASC); Angwin, 10 May 1960, L. Eighme ( 1♂ [p], CASC); same except 3 June 1975 ( 2♂♂ [p], CASC); same except 5 June 1975 ( 1♂ [p], CASC); same except 10 May 1978 ( 1♂ [p], CASC); same except 6 June 1978 ( 1♂ [p], CASC); same except 30 May 1984 ( 1♂ [p], CASC); Angwin, 8 May 1980, Peter Cowley ( 1♂ [p], CASC); Angwin, no date, H. B. Leech ( 5♂♂ [p], UCRC); Calistoga, 1 June 1948, D. Giuliani ( 1♂ [p], CASC); Conn Dam, 18 May 1968, E. S. Ross ( 1♂ [p], CASC); Huichica Creek , 17 June 1934, J. W. Tilden ( 1♂ [i], CASC); Mount Saint Helena, 16 June 1915, Van Dyke collection ( 1♀ [p], CASC); Mount Saint Helena, 9 June 1918, E. P. Van Duzee ( 2♂♂ [p], CASC); Mount Saint Helena, 26 May 1951 ( 1♂ [p], CASC); Mountain Mill House , Highway 29, 12 km north of Calistoga , 475–550 m, 11 June 1988, Paul H. Arnaud, Jr. ( 1♂ [p], CASC); Napa, 10 June 1931, A. T. McClay ( 1♂ [d], CASC); Saint Helena, in vineyard, 26 April 1986, Ed Salvestrin ( 1♂ [d], CASC); Sanitarium, 10 May 1960, R. Ratzlaff ( 1♂ [p], CASC); Nevada Co. : 6 miles south of Grass Valley , 18 May 1930, E. P. Van Duzee ( 1♂ [p], CASC); Grass Valley , 17 May 1930, E. P. Van Duzee ( 2♂♂ [p], CASC); Nevada City, 16 May 1930, E. P. Van Duzee ( 1♂ [p], CASC); Placer Co. : 10 miles northeast of Auburn , 5 May 1958, A. E. Menke ( 1♂ [p], LACM); Auburn, 20 April 1969, B. Swisley ( 1♂ [p], CASC); Auburn, 7 May 1969, B. Paul ( 1♂ [p], CASC); [county record only], Van Dyke collection ( 4♂♂, 1♀ [p], CASC); Foresthill, 9 February 1977, E. L. Klee ( 1♂ [d], CASC); San Benito Co. : Pinnacles National Monument, 26 June 1967, P. S. Bartholomew ( 1♂ [d], CASC); San Francisco Co. : San Francisco, 31 May 1905, Van Dyke collection ( 1♂ [d], CASC); San Francisco, 1 May 1931, J. A. Kusche ( 3♂♂ [d], CASC); San Luis Obispo Co. : Cerro Alto, 12 May 1979, Selfridge ( 1♂ [d], SBMNH); Reservoir Canyon, 29 April 1979, L. Verhovek ( 1♂ [d], SBMNH); San Luis Obispo, 24 April 1918, E. P. Van Duzee ( 2♂♂ [p], CASC); Tassajara Canyon, 30 April 1978, R. Hervey ( 1♂ [d], SBMNH); [county record only], 18 June 1989, L. Penzo ( 1♂ [d], SBMNH); San Mateo Co. : Crystal Springs Road, 16 April 1957, Cushner ( 4♂♂ [d], CASC); Crystal Springs Road, 27 April 1957 ( 11♂♂ [d], CASC); same except D. Rentz ( 4♂♂ [d], CASC); East Palo Alto , 6 May 1955, P. S. Bartholomew ( 1♂ [d], CASC); Jasper Ridge, Stanford University, 20 April 1952, P. S. Bartholomew ( 3♂♂ [d], CASC); same except 22 April 1962 ( 1♂ [d], CASC); Menlo Park, 10 May 1955, DHB ( 5♂♂ [d], CASC); Redwood City, 11 April 1943 ( 1♂ [p], UCRC); San Mateo, 25 April 1949, R. S. Beal ( 1♂ [d], ASUHIC); San Mateo, Van Dyke collection ( 1♂ [d], CASC); Westridge, 31 June 1959, P. S. Bartholomew ( 1♂ [d], CASC); Santa Barbara Co. : Refugio Canyon, 15 April 1962, P. van Duinwyk ( 1♂ [d], SBMNH); Santa Clara Co. : Alma, 28 May 1916, C. L. Fox ( 1♂ [d], CASC); Alma, Van Dyke collection ( 2♂♂ [d], CASC); Almaden, 28 April 1946, L. L. Lewallen ( 2♂♂ [d], UCRC); Alum Rock Park, San Jose, 26 June 1921, L. S. Slevin ( 2♂♂ [d], CASC); Alum Rock Park, 23 April 1948, P. H. Arnaud ( 1♂ [d], CASC); Alum Rock Park, San Jose, 22 April 1951, J. W. Green ( 1♂ [d], CASC); Alum Rock Park, 22 April 1958, William Walls ( 1♂ [d], CASC); Alum Rock Park, 5 May 1965, on wild blackberry, D. H. Kavanaugh ( 1♂ [d], CASC); Alum Rock Park, 1 May 1975, Harvey I. Scudder ( 2♂♂ [d], CASC); same except 25 April 1979 ( 1♂ [d], CASC); near Calaveras Reservoir, 13 May 1961 ( 1♂ [d], CASC); same except G. I. Hage ( 1♂ [d], CASC); Cupertino, 4 May 1937, K. S. Hagen ( 1♂ [d], CASC); Cupertino, 12 April 1950, R. S. Beal ( 2♂ [d], ASUHIC); Los Altos, 7 May 1921, W. M. Giffard ( 3♂♂ [d], CASC); Los Gatos, 23 April 1909, L. S. Slevin collection ( 1♂ [d], CASC); same except 20 May 1910 ( 1♂ [d], CASC); Los Trancos Creek , Stanford University, 10 May 1952, P. S. Bartholomew ( 1♂ [d], CASC); Mount Hamilton , 20 May 1933, grasses and low herbage, E. S. Ross collection ( 1♂ [p], CASC); Mount Hamilton , 14 April 1934, in poppy flowers ( 1♂ [d], CASC); Mountain View , 1909, R. Hopping collection ( 2♂♂ [d], 1♀ [d], CASC); Palo Alto, 22 March 1892 ( 1♂ [d], LACM); Palo Alto, 5 April 1892 ( 2♂♂ [d], LACM); Palo Alto, 6 April 1892 ( 6♂♂ [d], LACM); Palo Alto, 12 April 1892 ( 1♂ [d], LACM); Palo Alto, 20 April 1892, L. J. Muchmore ( 1♂ [d], LACM); Palo Alto, 25 April 1892 ( 1♂ [d], LACM); Palo Alto, 4 May 1892 ( 1♂ [d], LACM); Palo Alto, 21 April 1893 ( 1♂ [d], LACM); Palo Alto, 21 April 1895 ( 1♂ [d], LACM); Palo Alto, 22 April 1895 ( 1♂ [d], LACM); Palo Alto, April 1896 ( 1♂ [d], LACM); Palo Alto, 8 April 1896 ( 2♂♂ [d], LACM); Palo Alto, 16 April 1896 ( 1♀ [d], LACM); 22 April 1897 ( 1♂ [d], LACM); Palo Alto, April 1908, Van Dyke collection ( 1♂ [d], CASC); Palo Alto, 9 April 1981, S. F. Muzzio ( 1♂ [d], CASC); San Jose, April 1906 ( 1♂ [d], LACM); San Jose, 6 May 1956, Dave Ribble ( 1♂ [d], INHS); San Jose, front porch lights, 13 November 1960, student collector ( 1♀ [d], CASC); San Jose, 5 May 1965, Balcom ( 1♀ [d], CASC); San Jose, ex grass blade, 3 May 1976, Suzanne Muzzio ( 1♂ [d], CASC); same except ex Pinus, 16 April 1978 ( 1♂ [d], CASC); same except ex grass, 28 April 1979 ( 1♂ [d], CASC); Sand Hill Road, Stanford University, 30 March 1952, P. S. Bartholomew ( 1♂ [d], CASC); Silver Creek Hills, 11 April 1961, R. L. Macdonald ( 1♂ [d], UCRC); Silver Creek Hills, 28 April, 1966, A. R. Stephen ( 1♂ [d], CASC); Silver Creek Hills, 9 May 1968, A. and A. Gillogly ( 2♂♂ [d], LACM); Stanford University, May 1898, Kuwana ( 1♂ [d], LACM); Stanford University, 18 April 1902 ( 1♂ [d], LACM); Stanford University, Mar 19[blank] ( 1♂ [d], LACM); Stanford University, 11 April 1905 ( 1♂ [d], LACM); Stanford University, 13 April 1905 ( 1♂ [d], LACM); Stanford University, 20 March 190[blank] ( 1♂ [d], LACM); Stanford University, 4 May 190[blank] ( 1♂ [d], LACM; 1♂ [d], UCRC); Stanford University, 20 March 190 [blank] ( 1♂ [d], LACM); Stanford University, April 1923 ( 1♂ [d], LACM); Stanford University, 13 April 1923 ( 2♂♂ [d], LACM); Stanford University, 20 April 1923 ( 1♂ [d], LACM); Stanford University, April 1925 ( 1♂ [d], LACM); Stanford University, May 1928, Hungate ( 1♂ [d], LACM); Stanford University, April 1927, Shedd ( 1♂ [d], LACM); same except May 1927 ( 1♂ [d], LACM); Stanford University, April 1929 ( 1♂ [d], LACM); Stanford University, 30 April 1933, D. Scott, Jr. ( 1♂ [d], CASC); Stanford University, 28 April 1934 ( 1♂ [d], CASC); Stanford University, 13 May 1950, P. S. Bartholomew ( 2♂♂ [d], CASC); same except 21 May 1951 ( 1♂ [d], CASC); same except 10 May 1952 ( 1♂ [d], CASC); same except 5 May 1953 ( 1♂ [d], CASC); same except 17 May 1953 ( 4♂♂ [d], CASC); same except 27 April 1954 ( 1♂ [d], CASC); same except 29 April 1954 ( 1♂ [d], CASC); same except 17 April 1960 ( 1♂ [d], CASC); Stevens Creek , 5 May 1940, G. S. Mansfield collection ( 1♂ [d], CASC); Stevens Creek , 19 May 1974, E. L. Klee ( 3♂♂ [d], CASC); Stevens Creek area , 20 April 1950, Alice and J. G. Edwards ( 1♂ [d], CASC); Stevens Creek area , 28 May 1952 ( 1♂ [d], CASC); Sunnyvale, 29 March 1949, T. H. Lauret ( 1♂ [d], CASC); Sunnyvale, May 1971, D. H. Bartholomew ( 1♀ [d], CASC); Uvas Creek , 13 May 1979, J. G. Edwards ( 1♂ [d], CASC); William Street Park, San Jose, 14 May 1965, in tall grass, D. H. Kavanaugh ( 1♂ [d], CASC); [county record only], 25 April 1950, Alice and J. G. Edwards ( 3♂♂ [d], CASC); [county record only], 6–27 April 1974, P. S. Bartholomew ( 1♀ [d], CASC); Shasta Co. : South Fork Cow Creek , Millville, 7,000 ft, 13 May 1949, H. P. Chandler ( 1♂ [p], CASC); [county record only], F. W. Nunenmacher, 6 May 1913 ( 1♂ [p], CASC); Solano Co. : Putah Canyon, 16 April 1958, A. Menke ( 2♂♂ [p], LACM); Solano Lake , 24 April 1970, R. Melton ( 1♂ [p], LACM); Vacaville, 9 July 1967, Verda Fletcher ( 3♂♂ [p], CASC); Sonoma Co. : 3 miles northwest of Healdsburg , host weeds, 28 March 1986, John Guardeno ( 1♂ [d], CASC); 5.5 miles east of Guerneville , 23 April 1966, Peter Rubtzoff ( 1♂ [d], CASC); Bennett Mountain Lake , west of Kenwood , 1,180 ft, H. B. Leech ( 1♂ [d], CASC); Cazadero, 31 March 1934, G. E. Bohart ( 1♂ [d], CASC); Eldridge, 1 May 1912, Van Dyke collection ( 2♂♂ [i], CASC); same except June 1912 ( 5♂♂ [p], CASC); same except 9 June 1912 ( 1♂ [p], CASC); Geyserville, 27 April 1971 ( 1♂ [p], UCRC); Geyserville, 10 May 1979, E. L. Klee ( 1♂ [p], CASC); Healdsburg, 16 May 1974 ( 1♂ [d], CASC); Laguna de Santa Rosa , 31 April, 1960, J. Sedlacek ( 4♂♂ [d], CASC); Mark West Springs , 10 May 1930, E. P. Van Duzee ( 1♂ [d], CASC); same except 14 May 1930 ( 1♂ [d], CASC); Mount Saint Helena, 6 May 1930, Van Dyke collection ( 1♂ [d], CASC); Santa Rosa, 16 April 1890 ( 4♂♂ [d], LACM); Santa Rosa, Ricksecker ( 1♂ [d], CASC); Santa Rosa, 15 April 1934 ( 1♂ [d], LACM); Santa Rosa, 12 May 1940, J. W. Green collection ( 1♂ [d], CASC); Sobre Vista, 15 April 1910, Van Dyke collection ( 2♂♂ [i], CASC); same except 24 April 1910 ( 1♂ [d], CASC); same except 31 April 1910 ( 3♂♂ [d], CASC); [county record only] ( 6♂♂ [d], LACM); [county record only], 19 May 1952, J. Quast ( 1♂ [d], LACM); [county record only], Koebele collection ( 1♂ [d], 1♂ [p], CASC); Sutter Co. : Yuba City, 29 May 1971, Marc P. Hayes ( 1♂ [p], SBMNH); Yolo Co. : Capay, 29 April 1934, B. E. White collection ( 1♂ [p], CASC); Davis, 22 May 1948, A. T. McClay ( 4♂♂ [p], CASC); same except 5 May 1947 ( 1♂ [p], UCRC); same except 14 April 1950 ( 1♂ [p], CASC); same except 13 May 1950 ( 3♂♂ [p], CASC); same except 12 May 1951 ( 7♂♂ [p], CASC); Davis, 27 April 1958, F. D. Parker ( 1♂ [p], UCRC); Davis, 20 April 1960, L. Traynham ( 1♂ [p], SBMNH); Davis, 1 May 1964, R. L. Macdonald ( 1♂ [p], UCRC); Putah Canyon, 25 May 1938, J. W. Tilden ( 1♂ [p], CASC); Putah Canyon, 24 April 1950, E. J. Taylor ( 1♂ [p], CASC); Putah Creek , 15 April 2000, S. E. Haskins ( 1♂ [p], MAJC); same except 9–29 May 2000 ( 2♂♂ [p], MAJC); Rumsey, 29 April 1934, B. E. White collection ( 1♂ [p], CASC); same except 3 May 1936 ( 1♂ [p], CASC); same except 3 May 1938 ( 1♂ [p], CASC); Rumsey, 17 May 1958, A. E. Menke ( 2♂♂ [p], LACM); Yuba Co. : Marysville, 7 August 1937, in peach orchard ( 1♂ [d], LACM); county unknown: Sylvania, April, Ricksecker ( 4♂♂ [i], CASC); Sylvania, 5 May 1895, R. Hopping collection ( 4♂♂ [d], CASC); [state record only], 26 April 1908, R. Hopping collection ( 1♂ [d], CASC); [state record only], Leng, R. Hopping collection ( 1♀ [d], CASC); [state record only], Fall, Fenyes collection ( 1♂ [p], CASC); Rust, 30 April 1913, L. S. Slevin collection ( 1♂ [d], CASC); [no locality], ex Carl Fuchs collection via E. R. Leech collection ( 1♀ [d], CASC); [no locality], J. W. Green collection ( 1♀ [d], CASC); [no locality] E. S. Ross collection ( 1♂ [p], CASC). Doubtful localities, not mapped: ARIZONA: Santa Cruz Co. : Patagonia, April 1976, R. T. Ross ( 1♂ [d], CASC); OREGON: Marion Co.: Salem, 20 March 1961 ( 1♂ [d], ASUHIC); MEXICO: country record only, Ricksecker ( 1♂ [d], CASC).

Figures

Fig. 9. Dascillus davidsoni male, dorsal habitus. A) Traditional davidsoni-morph, Moraga Ranch, CA, B) Traditional plumbeus-morph, Oroville, CA, C) Light cuticle form of plumbeus-morph, Angwin, CA, D) Less-setose and partially abraded individual of plumbeus-morph, Putah Creek, CA. Image credit: Lucie Gimmel.

Fig. 10. Dascillus davidsoni, male terminalia. A–C) Specimen of davidsoni-morph from Mount Saint Helena, CA: A) Aedeagus, ventral view, B) Genital capsule, ventral view, C) Genital capsule, dorsal view. D–G) Aedeagus, ventral view: D) Specimen of plumbeus-morph from Jerseydale, CA, E) Specimen of plumbeus-morph from Putah Creek, CA, F) Specimen of davidsoni-morph from Sunol Valley, CA, G) Specimen from Sonoma County, CA.

Fig. 11. Dascillus davidsoni, female from Mill Valley, CA. A) Dorsal habitus (image credit: Lucie Gimmel). Ovipositor: B) Dorsal view, C) Ventral view.

Fig. 12. Distribution map for Dascillus davidsoni.