Scaptococcus californicus McKenzie, 1964

Ellenrieder, Natalia Von & Watson, Gillian W., 2019, A revision of the mealybug genus Scaptococcus McKenzie (Hemiptera: Coccomorpha: Pseudococcidae), with descriptions of the adult male and female of Scaptococcus occultans sp. n. from the southwestern United States, and the male of S. milleri McKenzie, Zootaxa 4554 (2), pp. 386-400 : 388

Scaptococcus californicus McKenzie, 1964

( Figure 1 )

Material examined. 52 ♀♀. U.S.A.: California: Inyo County : 1 adult ♀ holotype, 3 miles NW of Shoshome , on Cryptantha sp., 13.iv.1963, D.R. Miller leg. [ BME] ; 14 ♀♀ paratypes (13 adults, 1 immature), same data as holotype [ BME] ; 4 adult ♀♀ paratypes, same data as holotype [ CSCA]; San Bernardino County : 5 adult ♀♀, Kramer junction, on Amsinckia sp. and Malacothrix sp., 6.iv.1966, D.R. Miller leg. [ BME] ; 1 adult ♀, same data but [ CSCA] ; 1 adult ♀, same data but [ USNM] ; 4 adult ♀♀, same data but 26.iii.1968, on Caulanthus inflatus [ BME] ; 3 adult ♀♀, same data but [ USNM] ; 6 adult ♀♀, 5 miles N of Cajon Pass , 17.iv.1965, on Amsincka sp., D.R. & J.F. Miller leg. [ BME] ; 1 adult ♀, same data but [ USNM] ; 2 adult ♀♀, 5 miles E of Carson’s Well , 4.iv.1966, on Cryptantha sp. and Pectocarya platycarpa, D.R. Miller & M.L. Pitney leg. [ BME]; Riverside County : 1 adult ♀, 2 miles S of Palm Springs, Palm Canyon Road , 6.iii.1967, on Cryptantha sp., H.L. McKenzie leg. [ BME]. Arizona, Pima County : 4 adult ♀♀, 42 miles NW of Sells , on Lepidium thurberi , 16.iii.1968, D. R. Miller & R.W. Rust leg. [ BME] ; 1 adult ♀, same data but [ CSCA] ; 3 adult ♀♀, same data but [ USNM] ; 1 adult ♀, Madera Canyon, 17.iii.1968, on Calliandra eriophylla, D.R. Miller & D.S. Horning leg. [ BME] .

Amendment to McKenzie’s (1964) adult female description. Usually the antennae are 8-segmented, but are quite frequently 9-segmented (in the holotype, two paratypes and 15 additional specimens) or, rarely, 7-segmented. Several specimens possess a few quinquelocular pores on the venter of SV–VIII, interspersed among the multilocular pores.

First-instar nymph. Antenna 6-segmented; it shares with the adult female the presence of anterior and posterior ostioles, a plantar denticle on the claw, trilocular pores and setae flagellate and slender on dorsum and venter, absence of a circulus, and a simplified anal ring lacking cellular pores. Besides lacking a vulva, it differs from the adult female by lacking multilocular and quinquelocular pores. Modified oral collar tubular ducts were not detected.

Diagnosis. The adult female of S. californicus can be separated from other Scaptococcus species by the lack of a circulus; having modified oral collar tubular ducts, multilocular pores and, when present, quinquelocular pores restricted to the venter; and having an anal ring without cellular pores. The anal ring lacking cellular pores and absence of a circulus enables separation of female nymphs of S. californicus from those of the other two known Scaptococcus species, both of which have circuli and at least some cellular pores in the anal ring. The male of S. californicus is unknown.

Biology. Scaptococcus californicus occurs in sand dunes on the crown and roots of its hosts; adult females are each enclosed in a cyst-like, waxy ovisac, surrounded by loose particles of moist soil that also contains nymphs ( McKenzie 1967).

Hosts. Asteraceae : Malacothrix sp. [new host record]; Boraginaceae : Amsinckia sp., Cryptantha sp., Pectocarya platycarpa [new host record]; Brassicaceae : Caulanthus inflatus [new host record]; Fabaceae : Calliandra eriophylla [new host record].

Distribution. Arizona (Pima County) [new state and county records]; California (Inyo, San Bernardino, Riverside [new county record]) ( Fig. 1 ).

Figures

FIGURE 1. Distribution of Scaptococcus species.