Tytthus zwaluwenburgi Usinger

Henry, Thomas J., 2012, Revision of the Plant Bug Genus Tytthus (Hemiptera, Heteroptera, Miridae, Phylinae), ZooKeys 220, pp. 1-114 : 76-77

Tytthus zwaluwenburgi Usinger Figs 53, 54191-193

Cyrtorhinus zwaluwenburgi Usinger 1944: 148 (orig. descrip.), 1951: 5 (key).

Tytthus zwaluwenburgi : Carvalho and Southwood 1955: 19 (descrip.); Carvalho 1958: 159 (cat.); Schuh 1984: 192 (diag., host), 1995: 250 (cat.).

Diagnosis.

This species is readily distinguished by the uniformly yellow to testaceous coloration, except for the dark brown eyes and a vague brown area at the middle of the head.

Description.

Male (n = 1 paratype) (Fig. 53): Length to apex of hemelytron 2.30 mm, length to base of cuneus 1.66 mm, width across hemelytra 0.77 mm. Head: Length 0.29 mm, width across eyes 0.56 mm, interocular width 0.30 mm. Labium: Length 0.74 mm. Antenna (missing; after Schuh 1984): Segment I length (not given), II 0.61 mm, III (not given), IV (not given). Pronotum: Length 0.27 mm, basal width 0.75 mm.

Coloration: Uniformly yellow to testaceous, except for the dark brown eyes and a vague brown area on the middle of the head.

Structure, texture, and vestiture (after Usinger 1944): Head half again as broad as long, 11.5; 8, smooth, shining, and strongly convex above. Eyes slightly less than half as wide as interocular space, 2.75: 6. First antennal segment shorter than interocular space, 5: 6, second segment three times as long as first, third and fourth segments broken off. Rostrum nearly reaching apices of middle coxae. Pronotum somewhat duller than head, clothed with short, sparse, decumbent hairs; broader across humeri than width of head, 15: 11.5, and less than half as long as broad, 6.5: 15; front margin shallowly concave, lateral margins feebly sinuate, and hind margin slightly concave. Scutellum longer than pronotum at middle, 7: 6, subdepressed, the disk very sparsely clothed with appressed hairs. Hemelytron simple, distinctly but sparsely clothed with appressed hairs; costal margin slightly, evenly arcuate. Legs slender, clothed with short, inconspicuous, pale hairs. Claws with simple hairlike setae rather than arolia.

Male genitalia (after Schuh 1984): Left paramere (Fig. 191): Mitt-shaped; right arm stout, broad, apically acute; left arm slender, apically acute. Right paramere: Not illustrated. Endosoma (Fig. 192): S-shaped. Phallotheca (Fig. 193): Slender, bluntly rounded apically.

Female: (n = 1) (Fig. 54): Length to apex of hemelytron 2.53 mm, length to base of cuneus 1.80 mm, width across hemelytra 0.96 mm. Head: Length 0.29 mm, width across eyes 0.59 mm, interocular width 0.34 mm. Labium: Length 0.85 mm. Antenna: Segment I length 0.24 mm, II 0.61 mm, III and IV missing. Pronotum: Length 0.32 mm, basal width 0.80 mm.

Hosts.

Recorded from Boerhavia sp. ( Nyctaginaceae ) by Usinger (1944) and Schuh (1984). Usinger (1944) noted that the various species of the genus prey on delphacid eggs, but since "delphacids have not been reported on Canton Island and since both Cyrtorhinus and the cicadellid Nesaloha cantonis Oman were collected on Boerhaavia , it is possible that this new mirid is a predator on Nesaloha ."

Distribution.

This species has been reported from Baker Island, Howland Island, and the Phoenix Islands (Canton Island) in the central Pacific ( Usinger 1944, Schuh 1984).

Discussion.

Tytthus zwaluwenburgi was described from only three specimens (holotype, paratype, and one teneral specimen). Schuh (1984) studied the holotype and illustrated the male genitalia.

Type material examined.

Canton Island: 20 Nov 1940, R. Danner, 1 ♂ paratype (BPBM).

Other specimen examined.

Baker Island: 18 Apr 1935, E. H. Bryan, Jr., 1 ♀ (BPBM). Phoenix Islands: Canton Island, 16 Mar 1924, E. H. Bryan, Jr., 1 ♀ (BPBM).