Entomology Commons^™

Response By Reticulitermes (Isoptera: Rhinotermitidae) And Cryptocercus Punctulatus (Blattaria: Cryptocercidae) To Wood Infected With The Green-Stain Ascomycete, Chlorociboria Aeruginascens Aeruginascens, Deborah Waller

Biological Sciences Faculty Publications

Termites of the genus Reticulitermes Holmgren and the wood roaches Cryptocercus punctulatus Scutter were observed feeding on wood stained green by the ascomycete fungus, Chlorociboria aeruginascens aeruginascens (Leotiaceae), in a Virginia forest. However, in laboratory choice trials, both termites and wood roaches preferred unstained wood to stained wood. In no-choice feeding trials, Reticulitermes fed stained birch ate significantly less wood and weighed significantly less than termites fed unstained birch. These results indicate that natural host utilization patterns cannot be relied upon to indicate feeding preferences.

Pheromonal Composition Of Two Species Of African Amblyomma Ticks: Similarities, Differences And Possible Species Specific Components, Thomas Lem Price Jr.

Biological Sciences Theses & Dissertations

Two species of bont ticks, Amblyomma hebraeum and Amblyomma variegatum, common to Africa have been studied to compare types and quantities of compounds known or believed to serve as components of the attraction-aggregation-attachment pheromone (AAAP). A complex of attraction, aggregation and attachment pheromones are used by these ticks to detect hosts, mates and perhaps minimize interspecific breeding. Solvent extraction of pheromone emitting ticks followed by Gas Chromatography and Mass Spectrometry revealed little difference in the composition of the AAAP in these two species. However, subtle differences in the relative makeup of the pheromonal blend are noted, suggesting that such differences …

Evidence For The Sensory Receptor(S) Of The Mounting Sex Pheromone In Two Species Of Ixodid Ticks, Dermacentor Variabilis (Say) And Dermacentor Andersoni Stiles, James Stephen Phillips

Biological Sciences Theses & Dissertations

The foreleg claw sensilla were determined to be the receptors of the female contact sex pheromone, MSP (mounting sex pheromone), in D. variabilis, D. andersoni and A. americanum male ticks. In all three tick species, the claw sensilla consists of six anteriorly-directed setae arranged in three symmetrical pairs, two each on the opposite sides of the apotele of the claw and one on the ventral side. Behavioral bioassays and morphological study of these setae revealed that only the dorsal and middle (= lateral) pairs of claw sensilla are mechanogustatory, while the ventral pair are strictly mechanoreceptors. The dorsal and …

Vitellogenesis In Hyalomma Dromedarii (Acari: Ixodidae): A Model For Analysis Of Endocrine Regulation In Ixodid Ticks, Martin E. Schriefer

Theses and Dissertations in Biomedical Sciences

The egg yolk proteins, vitellins, and their hemolymph precursors, vitellogenins, were characterized in the ixodid tick Hyalomma dromedarii. Three vitellins were identified. The high molecular weight vitellins, VN A and VN B, were composed of seven homologous molecular weight subunit polypeptides, VN 1-7. VN A appears to be a dimeric form of VN B. VN C was composed of single polypeptide. Low levels of vitellogenin, were identified in western immunoblots utilizing antibody raised against purified vitellin. Adult protein and polypeptide profiles, including vitellin and vitellogenin, were characterized as a function of sex, tissue and reproductive development. Quantitative assessment of the …

Feeding By Reticulitermes Spp., Deborah A. Waller

Biological Sciences Faculty Publications

No abstract provided.

Evidence For The Role Of Ecdysteroids In The Genital Sex Pheromone Of Two Species Of Hard Ticks, Dermacentor Variabilis (Say) And Dermacentor Andersoni Stiles, Demar Taylor

Biological Sciences Theses & Dissertations

Neutering of part-fed females virtually eliminated copulatory behavior in Dermacentor variabilis and D. andersoni males. Extracts from the anterior reproductive tracts (ART) of part-fed (7 days) females restored the male copulatory behavior in conspecific neutered females, suggesting the presence of a genital sex pheromone (GSP). Similar extracts from unfed females did not restore the behavior, suggesting that the pheromone was produced during feeding. Perception of the GSP by sensillae on the male cheliceral digits was confirmed by electrophysiological techniques.

Ecdysteroids, specifically ecdysone and 20-OH-ecdysone were shown to be present in the anterior reproductive tracts in excess of amounts that could …

Host Selection In Subterranean Termites: Factors Affecting Choice (Isoptera: Rhinotermitidae), Deborah Ann Waller

Biological Sciences Faculty Publications

The effects of block size and species on preference were examined for the subterranean termite Reticulitermes sp. (Rhinotermitidae) in choice and no-choice tests. Termites significantly preferred Douglas fir over Ponderosa pine and red oak, irrespective of block size. The less-preferred woods were eaten in large amounts in no-choice tests, and all three woods appeared to be favorable for the termites and their gut protozoans. In single species tests, termites ate significantly more from larger blocks of Douglas fir, but ate similar amounts from large and small blocks of Ponderosa Pine and red oak. These results suggest that several factors can …

A Taxonomic Survey Of The Family Gyrinidae (Coleoptera) Of The State Of Virginia, Jerrold R. Harris

Biological Sciences Theses & Dissertations

The aquatic insect fanua of Virginia is not very well known. This is especially true of the order Coleoptera. There are few taxonomic studies on the families of Coleoptera found within the state, and one of the least known is the family Gyrinidae. It is the intent of this study to determine what species of Gyrinidae are found within the state and where they are found. Collections of the beetles were made throughout the state from March to December.

Twenty-one species of Gyrinidae were identified in Virginia, nine species of Dineutus and 12 species of Gyrinus. The family is distributed …

Characterization Of The Dna And Chromosonal Analysis Of Embryonic Dermacentor Variabilis (Say) Cells In Culture, Stanley Nicholas Mason

Biological Sciences Theses & Dissertations

Cultured embryonic Dermacentor variabilis cells were examined by spectrophotometric techniques to determine total cellular DNA concentration and guanine-cytosine content of the DNA and by differential staining procedures to define the karyotype further. The cells were found to have a mean DNA content of 16.98 pg and a DNA guanine-cytosine content of 49%. Chromosome banding attempts resulted in the specific characterization of four chromosomes and differential grouping of the seven remaining chromosomes. A previously unreported submetacentric chromosome was identified.

Life History Patterns Of Dytiscidae In A Temporary Pool, Annabel C. Blanco

Biological Sciences Theses & Dissertations

The Dytiscidae are one of the most distributed families of aquatic Coleoptera. In addition, they comprise one of the largest families in the order. With the exception of some European species, research in the ecology/life history of the Dytiscidae has been limited.

The patterns of appearance and disappearance of Dytiscidae were studied for one growing season, February to June, 1983, in a temporary pool in the Great Dismal Swamp. Fourteen species of larvae and twenty-four species of adults were collected. Definite temporal patterns were evident in larvae of Laccophilus spp., Laccornis difformis, Liodessus affinis, Uvarus granarius, Agabetes acuductus, and Hoperius …

Fine Structure Of The Nucleus And Cytoplasmic Feulgen-Positive Areas In The Developing Oocyte Of Argus (Persicargas) Radiatus, Bonnie J. Harding

Biological Sciences Theses & Dissertations

A transmission electron microscope analysis of the changes that occur in the nuclear chromatin and the Feulgen-positive areas of the oocyte cytoplasm as the female develops, feeds and mates is described. The description includes analysis of oocytes from three types of females: unfed, unmated; fed, unmated; and fed, mated. In all types, dense material passes through the extremely porous nuclear membrane where it accumulates in the cytoplasm.

Nuclei of previtellogenic oocytes appear the same in all females studied. Fibrillar bodies and up to four large nucleoli are seen. No typical chromatin is seen, but structures resembling nucleosomes appear throughout the …

Sex Pheromone Activity In The Foveal Glands In The Two Species Of Ixodid Ticks: Dermacentor Andersoni (Stiles) And Dermacentor Variabilis (Say), Lynn Anne Collins

Biological Sciences Theses & Dissertations

Sex pheromone activity in the foveal glands of female Dermacentor andersoni (Stiles) and Dermacentor variabilis (Say) is described. Autoradiography revealed the accumulation of ³⁶Cl in the foveal glands of females during their first 120 hours of feeding on a ³⁶Cl-labeled host. Emissions collected from these females contained a ³⁶Cl-labeled product. This product, however, was absent in emissions collected from the same females with their foveae dorsales obstructed.

Accumulation of ³⁶Cl in the foveal gland, in conjunction with the release of a ³⁶Cl-labeled product through the foveae dorsales, suggest localization of sex pheromone activity within these …

The Ecology Of The Dominant Tick Species In The Northwestern Portion Of The Dismal Swamp National Wildlife Refuge, Mary Keith Garrett

Biological Sciences Theses & Dissertations

Elements of the ecology of the two dominant man-biting ticks were studied during 1971-1973 in two locations in Southeastern Virginia, namely, what is now the Dismal Swamp National Wildlife Refuge and Newport News City Park. Tick species composition, relative abundance, density, and distribution in the two areas were compared. In addition, the Dismal Swamp locality was used as a test area for studies on the survival of native, lab reared and translocated Dermacentor variabilis (Say) and Amblvomma americanum (L.) in relation to selected abiotic factors. The Newport News locality served as a control area for these studies.

The species …