Download or read book The Leafhopper Genus Tiaja Oman Homoptera Cicadellidae with a Contribution to the Biosystematics of the Group written by Jane Rosamund Sawbridge and published by . This book was released on 1976 with total page 352 pages. Available in PDF, EPUB and Kindle. Book excerpt: The genus Tiaja Oman consists of eight known species of flightless leafhoppers of the subfamily Megophthalminae found along the western coast of North America between British Columbia and northern Mexico. Species occurring from the San Francisco Bay area northward are restricted to a narrow coastal zone within 1 km of the ocean; some of those species that occur farther south may be found inland as well as on the coast. Members of the genus occupy an unusual habitat in that most individuals are found on the undersides of their host plants or in the litter layer beneath them. Flightlessness and the position the insects occupy on their host plants are seen as adaptations to enhance survival in a windswept environment. Life history studies of T. friscana (Ball) and T. arenaria Oman show that nymphs normally pass through five nymphal ins tars although some individuals may have four or six nymphal ins tars. The final nymphal ins tar is of longer duration than any of the preceding ins tars but the length of the developmental period appears to depend on temperature conditions in the rearing chamber. The northernmost species, T. arenaria, is univoltine with obligatory diapause while T. friscana and T. montara Oman, two species of the central California coast, are multivoltine with no diapause under favorable conditions. Other species are presumed to be multivoltine. Host association studies show that members of the genus Tiaja are usually found associated with woody shrubs and that these shrubs may serve as feeding but not necessarily oviposition hosts. The oviposition host of T. arenaria is Fragaria chiloensis (L.) Duch. Infraspecific variation in disjunct populations of T. friscana is examined. These populations lie 550 km apart and the range of another species, T. montara, intervenes. Crossbreeding experiments show that while there is some genetic differentiation as a result of isolation, the populations are similar enough and hybridize to a sufficient extent to be considered members of the same species. Crossbreeding experiments between T. friscana and T. montara show that these allopatric species from the San Francisco Bay area hybridize to some extent when artificially placed together. However, fertility is considerably reduced compared to parental crosses and this is taken as evidence of the reliability of morphological features used for species differentiation in this genus. Factors influencing the success rates of these crosses are discussed. The presence of members of the genus on islands and in populations isolated from the remainder of a species despite the limited mobility of the group is discussed. It is speculated that dispersal of T. arenaria to Vancouver Island subsequent to Pleistocene glaciation, dispersal of T. insula Sawbridge to Santa Barbara Island following its submersion in the late Pleistocene, and the colonization of San Simeon by T. iris cana can be attributed to dispersal by drift of egg-containing host plant material aided by ocean currents and prevailing winds. Taxonomic information includes a discussion of the place of the Megophthalminae within the Cicadellidae, recharacterization of the genus Tiaja, a revised key to the eight known species, and species recharacterizations including morphological data, distributions, seasonal occurrence, and host and habitat information. Criteria for differentiation of nymphal ins tars through setal patterns and wing pad development are discussed and illustrated. It is concluded that further study of the habitats, life history, behavior, and cytogenetics of the Ulopinae and other members of the Megophthalminae will be necessary before current data on Tiaja can be used to help redefine relationships within and between these subfamilies.

Download or read book The Leafhopper Genus Tiaja Oman homoptera Cicadellidael with a Contribution to the Biosystematics of the Group written by Jane Rosamund Sawbridge and published by . This book was released on 1994 with total page 163 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Nearctic Leafhoppers Homoptera Cicadellidae a Generic Classification and Check List written by Paul Oman and published by . This book was released on 1949 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Leafhopper Genus Errhomus Homoptera Cicadellidae Cicadellinae written by Paul Oman and published by . This book was released on 1987 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Taxonomic Revision of the Leafhopper Genus Flexamia and a New Related Genus Homoptera Cicadellidae written by David A. Young and published by . This book was released on 1958 with total page 58 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Revision of the Genus Colladonus Homoptera Cicadellidae written by Mervin William Nielson and published by . This book was released on 1957 with total page 70 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Cicadellidae Or Leaf hoppers of South Carolina written by Frank Heidtman Lathrop and published by . This book was released on 1919 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Notes on the Generic Affinities of Certain Cicadellidae Homoptera written by Herbert Osborn and published by . This book was released on 1920 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Leafhopper Genus Giprus Homoptera Cicadellidae written by Jane Rosamund Sawbridge and published by . This book was released on 1972 with total page 178 pages. Available in PDF, EPUB and Kindle. Book excerpt: Members of the deltocephaline leafhopper genus Giprus Oman live on grasses, primarily in the desert-scrub, chaparral, and marine sand dune communities of western North America. Of 16 known species, 10 are undescribed. Recharacterization of the genus results in exclusion of Laevicephalus incongruus Oman. Differentiation of species is primarily dependent on male genital structures; characterization of species is through illustration, verbal description, and a diagnostic key. Infraspecific variation noted is primarily of two types: size and color variation in two dune-inhabiting species, and variation in shape and size of accessory aedeagal processes of G. siskiyou (Oman). The fifth instar nymph of Giprus is characterized. It is concluded that the distributional patterns of the Oregon Species of Giprus are not determined by host associations.

Download or read book Comprehensive Dissertation Index written by and published by . This book was released on 1984 with total page 832 pages. Available in PDF, EPUB and Kindle. Book excerpt: Vols. for 1973- include the following subject areas: Biological sciences, Agriculture, Chemistry, Environmental sciences, Health sciences, Engineering, Mathematics and statistics, Earth sciences, Physics, Education, Psychology, Sociology, Anthropology, History, Law & political science, Business & economics, Geography & regional planning, Language & literature, Fine arts, Library & information science, Mass communications, Music, Philosophy and Religion.

Download or read book The Leafhoppers of Minnesota written by John Thomas Medler and published by . This book was released on 1942 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Phylogenetic Study of the Leafhopper Genus Empasca Homoptera Cicadellidae written by Hugh Benson Cunningham and published by . This book was released on 1962 with total page 94 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Leafhoppers Cicadellidae written by P. W. Oman and published by Oxford University Press, USA. This book was released on 1990 with total page 382 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Taxonomy and Distribution of the Leaf hopper Genus Aphrodes Curtis Homoptera Cicadellidae in North America written by Terry Allen Klein and published by . This book was released on 1975 with total page 274 pages. Available in PDF, EPUB and Kindle. Book excerpt: The subfamily Aphrodinae is represented in the Nearctic Region by eight species contained in a single tribe, Aphrodini, and genus Aphrodes. The external and internal morphology, biology and ecology of the Nearctic members of the genus Aphrodes were investigated. Distributional evidence indicates that six of the eight species, belonging to the subgenera Aphrodes and Anoscopus, have been introduced from the Palearctic Region, presumably via maritime shipping. These six species occur either within the West Coast and adjacent land area or the East Coast and Great Lakes region and adjacent land areas, or both. The other two species, belonging to the subgenus Stroggylocephalus, are believed to be indigenous to North America and are not known to occur elsewhere. These two species have been recorded from numerous North American localities between 35°N and 58°N latitude. The irregular distribution of Nearctic members of the subgenus Stroggylocephalus indicates that these species now exist as relict populations. Two species of the subgenus Stroggylocephalus are recorded from Europe with one, agrestis, reported as occurring in North America. However, records of agrestis in North America were not verified, and prior records are believed to be erroneous. A single female of the subgenus Stroggylocephalus from Kentucky apparently represents a new species, the third known from North America. The Nearctic species of Aphrodes are here assigned to three subgenera: Aphrodes s. s., Anoscopus and Stroggylocephalus. Species differentiation is based primarily on features of the male genitalia. The structure, length, and number of retrorse spines of the aedeagus is unique for each species. The structure of the pygofer hook and style, the shape and setation of the genital plate and the absence or presence of a secondary papilliform structure adjacent to the pygofer hook were found to be useful in discriminating between some species and species groups. Morphological differentiation of females of some species is nearly impossible. The number of dentations on valve II of the ovipositor was found to be unreliable for discriminating species or species groups, in contrast to Readio's findings (1922). Color and color pattern of the forewing, face and crown in males and some females were frequently found to be useful for recognition of some species and species groups even though considerable amounts of variation occur within a species. Wing venation is variable; the venation of the two forewings of the same insect are often different. However, the length of the forewing was found to be a reliable character for distinguishing members of Aphrodes s. s. and Stroggylocephalus from Anoscopus. Crown L:W ratios of the females are usually smaller than the males and ratios of both sexes are unreliable for species differentiation because of the amount of infras pecific variation. Evidence regarding anatomy of the reproductive organs of species of Aphrodes, studied for the purpose of comparison with representatives of other genera and subfamilies of leafhoppers, although limited in scope, provides information useful for species differentiation in sexually mature males. The structure of the reproductive tracts supports the conclusion that the species studied belong to a single genus Aphrodes, or at most to two genera, Aphrodes and Stroggylocephalus. The Nearctic species of the genus Aphrodes are characterized through illustrations, verbal descriptions and a diagnostic key. Infraspecific variation consists primarily of differences in color, color pattern and size. The male genitalia are relatively uniform with some minor differences occurring in the length and rugosity of the styles, rugosity and crenulations on the lateral margin and apex of the pygofer hooks, and length and position of the retrorse spines of the aedeagus. The nymphal instars of three species--A. bicinctus, albifrons and serratulae--are described. The color and color pattern were found to be distinct for each of these species from the second ins tar to the final molt. Field and laboratory studies demonstrate that at least some of the species of Aphrodes are polyphagous. Two species, serratulae and albifrons, appear to prefer grasses, but will also feed on clovers. Those Nearctic species of Aphrodes that have been studied with reference to habitat preference are found in such places as near the base of plants, in soil surface litter, and under or around rocks and boards. Members of Aphrodes s. s. and Anoscopus are univoltine, with a few females surviving the winter. Adults of Stroggylocephalus have been recorded during nearly every month which suggests a polyvoltine life cycle.

Download or read book A Study of the Leafhopper Genus Circulifer Zakhvatkin written by David A. Young and published by . This book was released on 1954 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Systematic Study of the Leafhopper Genus Chlorotettix Homoptera Cicadellidae written by Paul Stanley Cwikla and published by . This book was released on 1988 with total page 934 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Comprehensive Dissertation Index Biological Sciences A E written by and published by . This book was released on 1984 with total page 838 pages. Available in PDF, EPUB and Kindle. Book excerpt: