A New Species of Cyrtopeltis from Coastal Vegetation in the Hawaiian Islands (Heteroptera: Miridae: Dicyphinae)

A new species, Cyrtopeltis kahakai Asquith, is described from the Hawaiian Islands. This species is specific to the strand plant Scaevola sericea (Vahl). WITH ENDEMIC SPECIES in at least 11 genera, the Hawaiian Islands have a rich and largely undescribed mirid fauna. The only speciose genus to have received taxonomic attention is Cyrtopeltis Fieber (Dicyphinae), with eight endemic species. Kirkaldy (1902) first recognized Cyrtopeltis in Hawai'i when he described C. hawaiiensis from Maui, and later Perkins (1911) added C. confusa from O'ahu. The Hawaiian Cyrtopeltis were then reviewed and new species added by both Carvalho and Usinger (1960) and Gagne (1968). It attests to the remarkable diversity of the Hawaiian fauna that, despite two revisions by resident taxonomists, we still lack a complete inventory of all species. In this paper, I described a new species of Cyrtopeltis from coastal areas of Hawai'i. Cyrtopeltis kahakai Asquith, n. sp. Figures 1-3 DIAGNOSIS: This is the smallest species of Cyrtopeltis in Hawai'i, and can be distinguished from all others by its total length of < 3.0 mm. It is similar to C. sidae Gagne and C. terminalis Gagne in that these species also have translucent, yellow coloration and pale setae. Because of its small size, C. kahakai keys to C. sidae in the most recent key to Hawaiian CJ!-rto]l.eltis (Gag~@JL1LdifIers from C. sidae in having the anterior arm of the genital capsule process larger and more strongly curved ventrally, the posterior process unlobed, and C. kahakai lacks the large 1 Manuscript accepted I March 1992. 2 Department of Entomology, University of Hawaii, Kauai Agricultural Research Station, 7370-A Kuamo'o Road, Kapa'a, Hawai'i 96746. tooth on the right dorsal margin of the genital capsule. In addition, the rostrum reaches only the mesocoxae in C. kahakai, and in C. sidae the rostrum reaches the metacoxae. DESCRIPTION: Male: Macropterous (Figure 1); small species, length 2.28-2.54 mm. Head round; eyes small, not reaching buccula ventrally, separated from pronotal collar by width of antennal segment II; occiput not constricted; tylus sloping anteriorly, not strictly vertical. All antennal segments cylindrical, All sightly enlarged distally; AI widest, distal segments progressively narrower; lengths: AI 0.16-0.19 mm; All 0.480.59 mm; AlII 0.43-0.54 mm; AIV 0.300.32 mm. Rostrum reaching mesocoxae. Pronotum trapezoidal, length 0.36-0.37 mm, width 0.63-0.68 mm; lateral margins nearly straight, posterior margin convex; anterior lobe laterally convex, posterior lobe flat; calli not elevated, only weakly defined by slight depression posteriorly. Hemelytra with sides weakly arcuate laterally. Entire body surface and all appendages translucent yellow; antennae, rostrum, and ventral surface ofhead pale yellow; eyes black; apex of rostrum and tarsi occasionally fuscous; spines and spinules on tibiae black. Surface of head, pronotum, and hemelytra shining. Vestiture on head and pronotal collar erect,_pale;_pronotum aQ --I hemelytra with inclined, pale, golden setae. Male genitalia: Posteroventral surface of genital capsule weakly and broadly curved dorsally (Figure 2). Process on ventral margin of genital opening bifurcate; posterior arm short, thick, straight; anterior arm sharply bent posteroventrally (Figure 3). Female: Macropterous; slightly larger than male, length 2.5-2.7 mm. Antennal segment 18 PACIFIC SCIENCE, Volume 47, January 1993 FIGURE I. Cyrtopeltis kahakai, dorsal habitus of male. LUl-.>s.hor.te.L1han that of male, length 0.450.5 mm. Pronotum broader, width 0.66-0.73 mm; more divergent posteriorly and more laterally convex. ETYMOLOGY: Name taken from the Hawaiian term kahakai, meaning"on the seashore." TYPE MATERIAL: Holotype: Male, Hawaiian Islands, Kaua'i, Moloa'a Bay, 8-V-1991, A. Asquith, ex Scaevola sericea (Vahl); deposited in the B. P. Bishop Museum, Honolulu. Paratypes: 28 males, 28 females: same data as holotype; deposited in the B. P. Bishop Museum. ADDITIONAL MATERIAL EXAMINED: Kaua'i: 4 males, 6 females, Kealia Beach, 22-V-1991, A. Asquith, ex Scaevola sericea (University of Hawaii, Kauai Research Station); 2 males, 2 females, Wail~a River mouth, II-V-1991, A. New Species of Cyrtopeltis-ASQUITH 19 Asquith (University of Hawaii, Kauai Research Station); Kalalau Valley beach, 4-X1991, A. Asquith, ex Scaevola sericea (University of Hawaii, Kauai Research Station). Moloka'i: 6 males, 8 females, Mo'omomi Dunes, 22-VI-1991, J. W. Beardsley coIl., ex Scaevola sericea (University of Hawaii Insect Collection). FIGURES 2-3. Cyrtopeltis kahakai, male genital capsule: 2, right lateral view; 3, left lateral view. lected nymphs ofwhat is probably this species from Scaevola at Ka'ena Point on O'ahu. All other species of Hawaiian Cyrtopeltis, except C. hawaiiensis Kirkaldy (known from Maui and Moloka'i), are restricted to a single island, making C. kahakai the only widespread species in the archipelago. As noted by Carvalho and Usinger (1960) and Gagne (1968), the Hawaiian Cyrtopeltis This species is restricted to the strand plant are host plant-specific and do not occur on Scaevola sericea Vahl (Goodeniaceae). AIrelated plants. For example, the morphologithough its host plant extends inland for at cal similarity between C. kahakai and C. sidae least 300 m from the shore, and occasionally probably indicates close phylogenetic affinity, farther on cliff faces, C. kahakai apparently yet their host plants belong to different has a narrower distribution, as I have not families (Goodeniaceae and Malvaceae, refound it more than a few meters above the spectively). This should not be surprising, high-water mark. Nymphs and adults are because the Dicyphinae in general occur on usually found deep among silky hairs in the plants with villous pubescence or those with leafaxils or within the inrolled leaf margins glandular trichomes, an ecological rather than and are not easily dislodged, thus it is not taxonomic determinate (Cassis 1984). Host __t=a.::ke~n~b:Ly---=b:"-'e""::a;.::ti:.::n:J:;g'--'o"-'r:,_:s~w-'-'e-:.:e'-"p:.;.:in~g"-'-.--"I~n,-,t--;h;-=e~l=ab=o,,;;r~a:;--_Qlants Qfthdfawaiian£.yr1opeltis-also-f~llo -II tory I have observed nymphs and adults of C. this pattern in having either glandular (Sida, kahakai feeding on both Scaevola leaves and Dubautia menziesii (A. Gray) D. Keck, dead conspecifics. I have made similar obserDubautia platyphylla (A. Gray) D. Keck, vations of C. hawaiiensis Kirkaldy, which Lysimachia) or silky hairs (Cyrtandra corsuggests that the other Hawaiian species, like difolia Gaud., Phyllostegia, Scaevola sericea most dicyphines, will feed on both plant and VahI). animal tissue (Cassis 1984). The recognized diversity of both the named Although at present C. kahakai is known and undescribed Hawaiian entomofauna only from Kaua'i and Moloka'i, I have colmakes the discovery ofyet another species not