Stephen W. Wilson

KEYS TO THE FAMILIES OF FULGOROMORPHA WITH EMPHASIS ON PLANTHOPPERS OF POTENTIAL ECONOMIC IMPORTANCE IN THE SOUTHEASTERN UNITED STATES (HEMIPTERA: AUCHENORRHYNCHA)

Abstract Planthoppers (Hemiptera: Fulgoromorpha) are of concern to agriculture in the southeastern United States because of their potential to cause significant damage to economically important plants. These keys are intended to aid diagnosticians attempting to identify planthopper crop pests. This work includes lists of pathogen vectors and those species considered pests of economically important plants grown in the region, brief descriptions of planthopper collecting and curating techniques, a summary of morphological features used for identification, a revised key for identification of planthoppers to family, a key to the economically important delphacids, and a list of literature useful for planthopper identification.

Potential planthopper vectors of palm phytoplasmas in Florida with a description of a new species of the genus omolicna (Hemiptera: Fulgoroidea)

Abstract Planthoppers (Hemiptera: Fulgoroidea) have been implicated in transmission of phytoplasmas that cause lethal decline in palms. Surveys of insects feeding on palms located in Florida resulted in the discovery of Omolicna joi sp. nov., described here. Patara albida (Hemiptera: Derbidae), a palm feeder, has become established in South Florida. Haplaxius crudus (Hemiptera: Cixiidae), the proven vector of the phytoplasma that causes lethal yellows (LY ), was thought to be restricted to the southern tier of Florida counties, thus limiting the distribution of LY . We found that H. crudus can overwinter consistently as far north as Gainesville (N 29.63380° W -82.37200°). Thus, the northern limit of LY might be a function of the physiology of the pathogens rather than the distribution of the vector.

Homoptera associated with sugarcane fields in Texas.

Sugarcane fields samples during 1989 and 1990 yielded 36 homopteran species, including 9 aphid, 16 cicadellid and 7 delphacid species. Species were also collected from the families Cicadidae, Cixiidae, Membracidae and Psyllidae. Although sampling techniques were different, our study documented 6 aphid, 13 cicadellid, and 5 delphacid species different from those collected in a Florida sugarcane study (Hall 1988). The potential pest species Sipha flava (Forbes) (Aphididae), Saccharosydne saccharivora (Westwood) (Delphacidae) and Perkinsiella saccharicida Kirkaldy (Delphacidae) were collected during both years. Several potential sugarcane disease-producing virus vectors were collected, including aphids, cicadellids, and delphacids. Surprisingly, no cercopids have been documented nor were any collected, although members of the genera Aeneolamia and Prosapia are serious pests of sugarcane in the neotropics.

Symposium: Insects in Altered Environments: Delphacodes Nigrifacies (Homoptera: Delphacidae): Field Biology, Laboratory Rearing and Descriptions of Immature Stages

The planthopper Delphacodes nigrifacies Muir, a species previously unreported from the United States, was collected in Florida from stands of Bahia grass (Paspalum notatum Flugge) and a mixed stand of St. Augustine grass (Stenotaphrum secundatum Kuntze) and Bermuda grass (Cynodon dactylon Pers.) from December 1984 to March 1986; it was reared in the laboratory and the immature stages described. D. nigrifacies feeds and reproduces on P. notatum and is apparently polyvoltine. Field collected adults were transferred to the laboratory and allowed to lay eggs on potted P. notatum. Upon emergence nymphs were separated and reared to adults. Durations of the five nymphal stadia were 3.95, 4.28, 4.59, 4.63, and 5.50 days, respectively. Nymphal instars differed in body size, number of pit-like sensoria, development of wingpads, number of metatibial and metatarsal spines, and the shape and dentition of the metatibial spur.

An Annotated Checklist of the Delphacid Planthoppers (Hemiptera: Delphacidae) of Florida with the Description of Three New Species and the New Genus, Meristopsis

ABSTRACT An annotated checklist of the 128 delphacid planthopper species of Florida, including host data, is presented based on combined specimen and literature records. The list includes 39 genera with 7 new combinations, 6 new synonymies, 3 new species and 16 new state records. The new genus Meristopsis (Delphacini) is here described with 2 new species, M. rhamphis and M. melanosteptos. Muellerianella meadi sp. nov. is also described.

Description, Life History, and Parasitism of a New Species of Delphacid Planthopper (Hemiptera: Fulgoroidea)

Abstract Delphacodes scolochloa Cronin & Wilson (Hemiptera: Fulgoroidea) is a newly discovered delphacid planthopper that feeds and oviposits exclusively on the stems of sprangletop, Scolochloa festucacea (Willd.) Link (Poaceae: Pooidae), in the prairie pothole region of northeastern North Dakota. D. scolochloa is bivoltine. It is also wing dimorphic, but populations are composed predominantly of flightless brachypters. Macropters incur a substantial cost in terms of reduced longevity and fecundity relative to brachypters. The parasitoid complex attacking D. scolochloa consists of two egg parasitoids, Anagrus nigriventris Girault and Anagrus columbi Perkins (Hymenoptera: Mymaridae), and one undescribed dryinid. The proportion of eggs parasitized averages 21%, and egg parasitization is density independent.

The planthopper genus Pentagramma in the United States: morphology of the male and female genitalia (Hemiptera: Delphacidae).

Abstract Five species in the delphacid planthopper genus Pentagramama have been described from the United States: P. bivittata Crawford, P. douglasensis Penner, P. longistylata Penner, P. variegata Penner, and P. vittatifrons (Uhler). Based on detailed examination of the male genitalia we synonymize P. variegata with P. douglasensis. Three of the species appear to be monophagous on bulrushes (Schoenoplectus spp.  =  Scirpus spp.; Cyperaceae). Penner (1947) provided descriptions of the species, illustrations of the heads, and a key for identification based on non-genitalic characters. We provide detailed descriptions and illustrations of the male and female genitalia, which are critical for accurate species identification.

Pelitropis Rotulata (Homoptera: Tropiduchidae): Host Plants and Descriptions of Nymphs

The 3rd, 4th, and 5th instars of Pelitropis rotulata Van Duzee are described and illustrated. Features useful in separating the nymphal instars include differences in body and wingpad sizes, spination of metatibiae and tarsomeres, and numbers of metatarsomeres and body pits. A list of 19 host plants observed in Florida and North Carolina is given.

Genetic Variability of the Invasive Species Metcalfa pruinosa (Hemiptera: Flatidae) in the Republic of Korea.

Abstract Metcalfa pruinosa (Say, 1830) (Hemiptera: Flatidae) has caused substantial agricultural damage since its recent introduction to the Republic of Korea; however, the source of this introduction is still unclear. To examine the genetic divergence and phylogenetic relationships among several populations of M. pruinosa from Korea and foreign countries, 251 COI sequences from 251 samples collected from Korea, France, Italy, Spain, Slovenia, and the United States were newly analyzed, together with seven published COI sequences from Canada. In total, 19 haplotypes were detected from the 258 COI sequences, and three haplotypes, H1, H3, and H9, were detected from samples in Korea. The MJ network and Bayesian inference revealed that the three haplotypes of Korea were closely connected with samples of Italy, Spain, Slovenia, France, and the United States. Our study revealed the possibility of multiple invasions of M. pruinosa from Europe and/or North America into Korea.

Elevational gradient of Hemiptera (Heteroptera, Auchenorrhyncha) on a tropical mountain in Papua New Guinea

Malaise trap sampling of Hemiptera (Heteroptera; Auchenorrhyncha) was conducted at 500 m intervals along an elevational gradient from 200 m to 3,700 m on the east slope of Mount Wilhelm, Madang Province, Papua New Guinea. Hemiptera had a decrease in morphospecies richness and overall abundance with increasing elevation, however, the Heteroptera did not exhibit either pattern. A few species were relatively abundant at each elevation, whereas the majority of species were represented by ≤5 specimens. Morphospecies richness of Auchenorrhyncha, Cicadomorpha, Fulgoromorpha, Cicadellidae, Cixiidae, and Derbidae also decreased with increasing elevation but abundance decline was not significant due to the large number of specimens captured at 200 m relative to those captured at higher elevations. The percentage of Cicadomorpha specimens decreased with increasing elevation relative to that of the Fulgoromorpha which increased with increasing elevation. Environmental factors that may influence patterns of species richness along the elevational gradient are discussed.