Parthenicus, REUTER, 1876

HENRY, THOMAS J., 2007, Synopsis of the Eastern North American Species of the Plant Bug Genus Parthenicus, with Descriptions of Three New Species and a Revised Key (Heteroptera: Miridae: Orthotylinae), American Museum Novitates 3593, pp. 1-32 : 2-5

PARTHENICUS REUTER

Parthenicus Reuter, 1876: 84 (orig. descrip.), Kirkaldy, 1906: 128 (list); Carvalho, 1958: 122 (cat.), Knight, 1968: 129 (n. spp., key western spp.); Henry, 1982: 355 (descrip., key eastern spp.); Henry and Wheeler, 1988: 436 (cat.); Schuh, 1995: 177 (cat.). Type species: Parthenicus psalliodes Reuter. Monotypic.

DIAGNOSIS: Species of Parthenicus are distinguished by the small size, dull to weakly shining, impunctate, dorsal surface, the absence of a basal carina on the head, the sericeous and scalelike setae on the dorsum, and the saltatorial hindlegs. The enlarged or swollen hindfemora give species in this genus the capability to jump, a trait that is especially apparent in brachypterous females and nymphs.

DESCRIPTION: Small, length 4.5 mm or less (eastern U.S. spp. 3.5 mm or less), elongate oval, impunctate; head without a distinct carina, eyes large, strongly granulate (more so in males); labium extending to metacoxae or beyond; pubescence simple, intermixed with golden, silvery, and/or black sericeous to scalelike setae, with black, scalelike setae especially abundant on cuneus and apical area of corium; hemelytra subparallel; males macropterous with the hemelytra and membrane well developed; females macropterous or brachypterous, membrane and cuneus often strongly abbreviated or coleopteriform, with the claval suture absent, forming a beetlelike ‘‘elytron’’; hindfemora strongly saltatorial; and parempodia fleshy and convergent. Vesica enclosed in a prominent phallothecal sheath and usually bearing one or two simple spiculi; the left paramere usually C-shaped, with base thickened and the arch of the C gradually tapered; and the right paramere ranging from straight, thickened, and spined distally to slender and arching or C-shaped.

DISCUSSION: Considerable variation in col- or and markings of some species makes study of male genitalia essential for positive identification of species. The parameres, though relatively simple compared with many orthotylines, are distinctive for most species (Knight, 1964; Henry 1982; Scudder and Schwartz, 2003). The left paramere ( figs. 25 , 28, 56, 74) is somewhat C-shaped, with the distal neck becoming much more slender than the base. The right paramere is comprised of a stout stem, usually with an apical spine or tubercle ( figs. 57 , 75 ), often with an acute lateral process or serrate ridge (fig. 29), or may be more slender, arching, and C-shaped ( fig. 26 ). The phallotheca ( figs. 27 , 30, 59, 77) is attached to the phallobase, but it protrudes well into the genital capsule opening and is visible behind the parameres when view caudally. This is unusual for most genera of Orthotylini I have studied, and is analogous only with members of the tribe Ceratocapsini and at least some Austromirini .

An analysis of relationships within Parthenicus is beyond the scope of this paper and must await a comprehensive generic revision. There are, however, clear indications of species groups based on male genitalia, even within the eastern species. The parameres are very homogeneous among most of the eastern species ( Henry, 1982). The left paramere groups the species P. cruentus , P. juniperi , P. knighti , P. psalliodes , P. rufus , P. taxodii , P. vaccini , and P. weemsi , and the right paramere groups these same species, with the exception of P. cruentus and P. vaccini . Interestingly, the eastern species grouped by parameres also are the ones having only fully macropterous females. Parthenicus cruentus , P. sedumicola , P. vaccini , and P. wheeleri all have some form of brachyptery in females, a trait commonly seen in species from arid habitats, including pine barrens of the East where P. vaccini is found ( Henry, 1978; Roble and Hoffman, 2000).

The relationship of Parthenicus with other Orthotylinae also is unknown. Schuh (1974) considered Parthenicus to have typical Orthotylus - type male genitalia, with welldeveloped, long, heavily schlerotized spiculi on the vesica. My dissections confirm that each eastern species has at least one, and often two, simple spiculi ( figs. 27 , 30), one of which may be relatively elaborate ( fig. 76 ), with multiple processes. As noted above, of all Orthotylini I have examined, Parthenicus is the only genus having the phallotheca visible externally within the genital capsule opening, a condition not too unlike that found in the Austromirini and Ceratocapsini .

KEY TO THE SPECIES OF PARTHENICUS IN EASTERN UNITED STATES

1. Tibial spines without distinct spots at bases or, at most, with a few vague spots on the basal third of the hindtibia............... 2

– Tibial spines with distinct red or brown spots at bases on all tibiae................. 6

2. Metafemora strongly infuscated; dorsum with black scalelike setae................ 3

– Metafemora uniformly pale yellow or testaceous, never fuscous; dorsum without black scalelike setae.................... 5

3. Pronotum and hemelytra usually pale to yellowish brown, lacking red spots, but usually tinged with red or salmon pink, especially on cuneus; scutellum predominantly fuscous; hindfemora reddish brown to almost fuscous, except for a narrow pale area along ventral surface; black scalelike setae concentrated on scutellum and apical one-third of corium; both males and females macropterous; distribution widespread in the eastern United States; hosts Juniperus spp. and other Cupressaceae .............................. juniperi (Heidemann)

– Pronotum and hemelytra pale, with scattered red to reddish-brown spots; scutellum pale, sometimes weakly infuscated basally, but always with apex pale; hindfemora uniformly red to reddish brown on distal two-thirds, never pale ventrally; black scalelike setae more evenly scattered on hemelytra or nearly absent; male macropterous, known females strongly brachypterous.............. 4

4. Antennal segment I in males longer than width of vertex between eyes, in females subequal to width of vertex; left paramere ( fig. 56 ), right paramere ( fig. 57 ); distribution Arkansas; host Sedum sp. ........ sedumicola , n.sp.

– Antennal segment I in males and females less than width of vertex between eyes; left paramere ( fig. 74 ), right paramere ( fig. 75 ); distribution Oklahoma and Texas; hosts selected species of Poaceae .. wheeleri , n.sp.

5. Dorsum uniformly yellow, without red or fuscous markings; hemelytral membrane smoky gray; rostrum short, just reaching middle of metacoxae; distribution Maryland to Florida, west to Missouri; host Taxodium distichum ............... taxodii Knight

– Dorsum yellow to testaceous, with the base and outer margin of the clavus and base of cuneus accented with red or small red spots, and basal angles of scutellum weakly infuscated; hemelytral membrane uniformly fuscous to black; rostrum long, extending beyond metacoxae; distribution coastal Florida; host unknown.............. knighti Henry

6. Dorsum and ventral surface predominantly deep red to reddish orange, with only a few, small, irregular pale areas showing through red............................ 7

– Dorsum and ventral surface pale grayish, testaceous, or pale brownish to reddish orange, not predominantly red or reddish

11 Jul 1986). 2, P. cruentus , female (same data as for male). 3, P. juniperi , male (Maryland, Montgomery Co., orange, with or without red or brown spots.......................... 8

7. Corium and clavus uniformly deep red to reddish orange with only a few fine, irregular, pale areas; white scalelike setae concentrated narrowly along posterior pronotal margin, basal half of scutellum, and apex of clavus; spots at bases of tibial spines small, red, often indistinct or diffused; distribution Florida, Georgia, and North Carolina; hosts Hypericum spp. ........... rufus Henry

– Corium deep red to reddish orange, clavus largely pale with only a few small, scattered, red spots; pronotal disk, scutellum, and clavus densely clothed with white scalelike setae; spots at bases of tibial spines distinct and deep red to dark brown; distribution Florida; host Ceratiola ericoides .................... weemsi Henry (dark form)

8. Dorsum, first and second antennal segments, and legs pale gray or grayish green, with numerous brown to fuscous spots; wing membrane white with two fuscous clouds apically; females usually brachypterous; distribution eastern coast, west to Michigan in the north; host Hudsonia spp. and Lechia maritima ........... vaccini (Van Duzee)

– Dorsum testaceous or pale brownish to reddish orange, with numerous to only a few red spots on dorsum.................. 9

9. Dorsum pale brownish or reddish orange, with only a few brown or red spots at base and apex of corium, spots on legs red; antennae uniformly pale testaceous, without spots; wing membrane smoky brown; females macropterous; distribution Florida; host Ceratiola ericoides ......... weemsi Henry (pale form)

– Dorsum pale whitish or yellowish brown, with numerous red spots............... 10

10. Hemelytral membrane uniformly dark or fumate; males and females always macropterous; distribution Florida and South Carolina to Texas; hosts Asteraceae ... psalliodes Reuter

– Hemelytral membrane pale translucent with two quadrate fumate blotches on outer margin; males macropterous, females often brachypterous with wing membrane reduced; distribution eastern Nebraska; host Asteraceae ............. cruentus , n.sp.

Figures

Figs. 25–27. Male genitalia of Parthenicus cruentus. 25, Left paramere. 26, Right paramere. 27, Vesica and phallotheca. Figs. 28–30. Male genitalia of Parthenicus psalliodes. 28, Left paramere. 29, Right paramere. 30, Vesica and phallotheca.

Figs. 56–59. Male genitalia of Parthenicus sedumicola. 56, Left paramere (a, dorsal aspect; b, caudal aspect). 57, Right paramere (a, caudal aspect; b, anterior aspect). 58, Vesica. 59, Phallotheca.

Figs. 74–77. Male genitalia of Parthenicus wheeleri. 74, Left paramere. 75, Right paramere (a, caudal aspect; b, anterior aspect). 76, Vesica. 77, Phallotheca.