A REVIEW OF TOYA (HEMIPTERA: DELPHACIDAE) FROM THE NEW WORLD

1. A A B Figure 2: Comparative frons view for: A) T. propinqua & B) T. wetmorei. B Table 1: A synoptic list of specimens examined, including localities. A B Figure 3: Comparative caudal view of the genitalia capsule for: A) T. propinqua & B) T. wetmorei. A REVIEW OF TOYA (HEMIPTERA: DELPHACIDAE) FROM THE NEW WORLD Anthony T. Gonzon, Jr., University of Delaware, Newark, DE, 19716, atgonzon@udel.edu Department of Entomology & Wildlife Ecology ABSTRACT The genus Toya is currently represented in the New World by five species: Toya argentinensis (Muir 1929) from Argentina, T. boxi (Muir 1929) from Brazil; T. venilia (Fennah 1959) from the West Indies; T. iaxartes (Fennah 1959)from St. Lucia; and T. propinqua (Fieber 1866) from throughout the region. Specimens resembling Toya were collected during the Great Smoky Mountains All Taxon Biotic Inventory that were either undescribed species, or species currently assigned to the wrong genus. These specimens led to this review of Toya in which all available New World Toya specimens were examined, along with the type species, Toya attenuata Distant, 1906, from Sri Lanka. The definition of the genus is emended with reference to New World species, and the generic placement of each species reconsidered. In addition, some species from the polyphyletic genus Delphacodes that appeared to belong in, or are related to, Toya and were compared to Toya for possible placement, including D. wetmorei (Muir & Giffard 1924), D. fallax Muir 1926, D. dolosa Muir 1926, D. idonea Beamer 1947, D. axonopi (Crawford 1914), and D. nigra (Crawford 1914). Of the considered species, only Toyapropinqua and Delphacodes wetmorei appear to belong in Toya. Four species, D. idonea, D. nigra, D. axonopi, and T. boxi form a natural group related to Toya. The remaining considered species are Syndelphax or unplaced. INTRODUCTIONThe genus Toya Distant 1906 contains 42 species (C. Bartlett, pers. comm.), with most in tropical and sub-tropical habitats of the Old World. Toya is represented in the New World by 5 described species with only one, Toya propinqua, known north of Mexico. This revision of Toya was motivated by the discovery of specimens during the Great Smoky Mountains National Park All Taxon Biotic Inventory (GSMNP ATBI) (Sharkey 2001, Bartlett & Bowman 2004) that appear to belong to Toya, but not Toya propinqua. Further, two species from north of Mexico, currently in Delphacodes, resemble Toya and may be more properly placed in that genus: Delphacodes idonea Beamer, 1947, and D. wetmorei (Muir & Giffard 1924). Other species currently in Toya, while externally similar, differ in regard to genitalic structure and may be better placed in other genera. My purpose was to revise the taxonomy of the New World members of Toya and provide notes on similar species. Figure 5: Delphacodes idonea, ♂, lateral view • DISCUSSION • The GSNMP ATBI specimens that motivated this research were both found to be described species. • The GSMNP ATBI specimen of T. propinqua, while slightly different in position and strength of aedeagal teeth, was within the range of observed variation for the species. • The D. idonea specimen was outside its known range and not expected in the Park. • Toya can be best separated from other delphacid genera by the combination of the expanded pygofer and the structure of the diaphragm. • Delphacodes wetmorei fits the definition and is here transferred to Toya. Figure 1: Toya propinqua, ♂, lateral view. Toya propinqua (Fieber, 1866) (Figs. 1, 2A, 3A) Diagnosis: Color: Carinae on frons very pale with pale to darkened, mottled intercarinal regions. Structure: Male pygofer with projections often concealing apex of parameres. Diaphragm well-developed, with an elongate, dorsally produced, parallel sided armature; strongly bifurcated at the apex. Remarks:Several features of T. propinqua exhibit variation although none was sufficiently large or consistent to designate new species or subspecies. Other features were constant among specimens from all localities, including those from other world regions. MATERIALS AND METHODS All available New World specimens of Toya, and similar Delphacodes species were examined, plus two specimens of the type species Toya attenuata from Sri Lanka (Table 1). A total of 426 individuals were examined including type material but excluding tentatively identified females and Old World Toya species. Figure 6: Comparative caudal view of the genitalia capsule for: A) D. idonea & B) D. axonopi. • Delphacodes idonea (Figs. 5, 6A, 7A), D. axonopi (Fig. 6B), and D. nigra all share similar features representing a new genus defined by: • Genital diaphragm developed, concave in structure, lacking a produced armature. • Processes on Segment X originating below dorsal margin and separated at base. • Heavily armed aedeagus consisting of strong rows of teeth produced along the dorsal and lateral margins with a smaller row ventrally. Toya wetmorei (Muir and Giffard, 1924) New Comb. (Figs. 2B, 3B, 4) Diagnosis: Color: Carinae on frons with solid darkened intercarinal regions. Structure: Pygofer with projections directed medially, appearing truncate and apically notched. Diaphragm armature broad and elongated, projecting dorsally, bifurcated and sub-parallel at apex, sometimes appearing as a sheath ventrally obscuring base of aedeagus. Remarks: This species is placed in Toya based upon the expansion of the pygofer and the presence of the bifurcated diaphragm armature. T. wetmorei exhibits a truncated expansion with a notched appearance vs. the more tapered and elongated expansion in T. propinqua. The parameres are widest mid-length, expanding from the base, and narrowing to near apices where they appear slightly notched with rounded margins. The parameres are difficult to separate from Delphacodes idonea. Male specimens were dissected for identification following techniques described in Wilson & McPherson (1980). Identifications were made using descriptions and keys based on male genital structures (e.g., Muir & Giffard 1924). To understand the definition of the species, I also examined the primary type specimens of D. wetmorei, D. fallax, D. dolosa, D. nigra, D. axonopi, and D. boxi. A B Figure 7: Comparative frons view for: A) D. idonea & B) T. boxi. Following identifications, I compiled summary diagnoses for Toya and included species.Morphological terminology follows that of Metcalf (1949) and Asche (1985). Measurements and photographs were made using a Nikon SMZ-1500 Digital Imaging Workstation with a Nikon DS-U1 digital camera and Eclipse Net Imaging software (version 1.16.6). Photo scale bars indicate 0.5mm. • Toya boxi (Fig. 7B), T. venilia, and T. argentinensis differ from the amended definition of Toya and the Delphacodes idonea group and are species incertae sedis. • Toya boxi and T. venilia differ from Toya by the structure of the diaphragm, and from the D. idonea group by features of the aedeagus. • Toya argentinensis differs from both groups by the highly expanded diaphragm armature. • Toya iaxartes, currently known only from the type, has been requested for examination. Illustrations of the genitalia of this species indicate that it is not Toya and should be placed incertae sedis at this time. • From this review, only Toya propinqua and T. wetmorei appear to represent this genus in the New World. • Ongoing research on New World Delphacini is anticipated to place species incertae sedis and define several new species segregates from the polyphyletic genus Delphacodes, including the D. idonea group. RESULTS The potential new species identified during the GSMNP ATBI were not new, but were determined to be T. propinqua and D. idonea. The diagnoses of the genus Toya and two species and comparative notes on Delphacodes idonea, D. axonopi, D. nigra, Toya boxi follow. Bold print indicates features of diagnostic significance. Genus Toya Distant, 1906 Diagnosis: Color: Body yellowish-tan, carinae paler. Intercarinal regions of frons bordered with dark brown to entirely dark brown. Wings transparent to translucent. Structure: Diaphragm of pygofer well-developed, armature produced, parallel-sided, bifurcate at apex. Parameres dorsocaudally directed, broad with produced apical-lateral margins.Segment X with pair of ventrally directed caudal processes from mid-dorsal margin, closely approximated at base. REFERENCES Asche, M. 1985. Zur Phylogenie der Delphacidae Leach, 1815 (Homoptera: Cicadina: Fulgoromorpha). Marburger Entomol. Publ. 2(1), volume 1 pp. 1-398, volume 2 pp. 399-910. Bartlett, C. R. and J. L. Bowman. 2004. Preliminary Inventory of the Planthoppers (Hemiptera: Fulgoroidea) of the Great Smoky Mountains National Park, North Carolina and Tennessee, U.S.A. Entomol. News 114(5): 246-254. Metcalf, Z. P. 1949. The redescription of twenty-one species of Areopidae described in 1923. J. Elisha Mitchell Sci. Soc. 65(1): 48-60 plus, 4 plates. Muir, F. A. G. and W. M. Giffard. 1924. Studies in North American Delphacidae. Bull. Exp. Stn. Hawaiian Sugar Planters' Assoc., Entomol. Ser., Bull. 15: 1-53. Sharkey, M. J. 2001. The All Taxa Biological Inventory of the Great Smoky Mountains National Park. Fla. Entomol. 84: 556-564. Wilson, S. W. and J. E. McPherson. 1980. Keys to the planthoppers, or Fulgoroidea, of Illinois (Homoptera). Transactions of the Illinois Academy of Science 73: 1-61. ACKNOWLEDGEMENTS I would like to thank Dr. Charles Bartlett for guiding me throughout this project. I would also like to thank Dr. Doug Tallamy and Dr. Diane Herson for their assistance, support, and helpful comments. I would like to acknowledge the assistance of the National Park Service, particularly Keith Langdon and Becky Nichols, as well as Ian Stocks and Chuck Parker with the USGS and Jeanie Hilten with DLIA. The University of Delaware Undergraduate Research Office provided financial assistance for this project. Figure 4: Toya wetmorei, ♂, lateral view.