Thesis (Ph. D.)--Virginia Polytechnic Institute, 1962. / Vita. Abstract. Includes bibliographical references (leaves 77-86). Also available via the Internet.

Thesis--University of Florida. / Description based on print version record. Typescript. Vita. Includes bibliographical references (leaves 120-128).

Thesis--University of Florida. / Description based on print version record. Typescript. Vita. Includes bibliographical references (leaves 196-211).

Thesis--University of Florida, 1975. / Description based on print version record. Typescript. Vita. Includes bibliographical references (leaves 97-103).

No description available.

No description available.

A preliminary experiment was conducted during the horn fly season at Blacksburg, Virginia from May through September, 1959, to determine the relationship of weather conditions to horn fly populations on 3 breeds of dairy heifers. Daily records of the fly populations on 10 animals selected at random from a mixed herd of Holstein, Guernsey, and Jersey yearling heifers were made. In addition, the daily minimum and maximum macrotemperatures and relative humidities, the approximate wind direction, and the amount of sunlight or cloud coverage were recorded. Usually there was a significant difference between the number of horn flies on Holstein and that on Guernsey and Jersey heifers. Horn flies generally preferred the dark colored areas of bicolored cattle during the hours of daylight, and they preferred the black of the Holstein rather than the tan of the Guernsey. When the macrotemperature was above 85°F, many of the flies were found on the white skin of the belly and udder area of a heifer. During inclement weather the flies were observed on both the white and dark colored areas of all the heifers. Macrotemperature and relative humidity influenced the horn fly populations within the biocenose. Light rain and winds of less than 20 miles per hour were found to have a negligible effect on the number of flies in the populations; however, significant population decreases were attributed to heavy rain, wind in excess of 20 miles per hour. Often, when the macrotemperature was below 55°F, light rain or wind of low velocity influenced movement of the flies to more sheltered areas on the host. The apparently preferred macroclimate for horn flies was: temperature of 73 to 80°F; relative macrohumidity of 65 to 90%; scattered light showers; and no wind. During the horn fly season of 1960, a second experiment was conducted to correlate the effect of the macro-environment on the micro-environment within the ½ inch mantle of the animal, and also to correlate the locations of horn flies within this mantle with various factors of the micro-environment. (Daily macro-environmental data, including air temperature, relative humidity, wind direction and velocity, amount of cloud coverage, and precipitation, were recorded as in the preliminary experiment of 1959.) Methods for measuring the micro-environment were devised, and the data obtained were analysed statistically and interpreted. Accordingly, the effects on horn fly populations of dark skin color, low temperature, and low humidity were highly significant at the 1% level; the effects on horn fly populations of high humidity and precipitation were significant at the 5% level; and the effect of high temperature on horn flies was not significant at the 5% level. According to the results of the second experiment, the horn flies apparently sought certain micro-environmental conditions which were most commonly observed on Holstein heifers. Within the mantle of micro-environment, horn flies appeared to prefer an air temperature of about 85°F, a skin temperature of about 97°F, and a relative humidity of about 65%. When such conditions were not available to the horn flies on the sides and backs of Holstein heifers, the flies usually found near optimum conditions along the belly midline for each of the 3 breeds of heifers. / Ph. D.

There is a discrepancy in the current literature concerning the stage of development in which horn flies arrest during pupal diapause. A study was therefore conducted to describe the morphologies of horn fly pupae and its central nervous system (CNS) throughout nondiapause pupal development and diapause. Morphologies of diapausing pupae and CNS indicated that developmental arrest occured early in pupal development during the interval between head eversion and pupal-adult apolysis. Morphological descriptions are necessary for defining compariable tissues between nondiapausing insects and diapausing insects. These tissues can then be used for molecular differential analysis to determine genes specific to either diapause or nondiapause. One such differential analysis technique, subtractive hybridization, was used to isolate putative diapause up-regulated genes from the horn fly. Seven different cDNAs were closed and partially sequenced. Comparisons of the cDNA sequences with known DNA and protein sequences indicated homology with transferrin, cytochrome oxidase I, Kunitz family serine protease inhibitor, tyrosine hydroxylase (TH), and carboxylensterase. Two cDNAs did not have homology to entries in DNA and protein databases. Northern blot analyses were used to study expression of each gene by probing total RNA extracted from whole pupae throughout nondiapause pupal development and diapause. Expression of TH was also determined in total RNA extracted from CNS tissue of nondiapausing and diapausing pupae. Cytochrome oxidase was equally expressed in nondiapause and diapause destined pupae, and therefore not considered to be a diapause up-regualted gene. Expression patterns differed slightly for each of the remaining clones; however, expression tended to be highest in diapause destined pupae during pupation compared to nondiapausing pupae. These genes and their products are involved in many aspects of insect phsiology including metamorphosis, melanization and sclerotization of the puparium and cellular defense. The possible functions of these genes and products are discussed in the context of the diapause process. / xii, 92 leaves : ill. ; 28 cm.

no abstract provided by author / Master of Science

Orientador: Angelo Pires do Prado / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-05T02:17:20Z (GMT). No. of bitstreams: 1 Lima_LuizGustavoFerraz_D.pdf: 1683443 bytes, checksum: f27b22a1767db423773354723196c9c2 (MD5) Previous issue date: 2005 / Resumo: Foram avaliadas entre 2002 e 2004, as influências da ação de insetos coprofágicos de dois tratamentos com endectocida (ivermectina), no desenvolvimento da ¿mosca-dos-chifres¿ (Haematobia irritans) (L.1758), em fezes bovinas, no município de Araçatuba, SP, Brasil, bem como da ação coprofágica. No campo, foram capturadas ¿mosca-dos-chifres¿ e coletadas as fezes de bovinos tratados (ivermectina) e não tratados (controle). Para avaliar o desenvolvimento da mosca nos grupos, em condição de temperatura laboratorial e ambiental, os ovos das moscas foram obtidos em laboratório e contadas as larvas inoculadas em fezes bovinas. Considerou-se como resultado dos testes, o número de ¿moscas-dos-chifres¿ emergidas, do número de larvas inicialmente inoculadas. O grupo não tratado obteve maior número de moscas, comparativamente ao grupo tratado, tanto em condição de temperatura laboratorial, como em condição ambiental. O tratamento mensal dos bovinos impediu o desenvolvimento da ¿mosca-dos-chifres¿ por até 30 dias em todos os testes, e no tratamento com única dose, as moscas emergiram a partir do 28º dia após sua aplicação. Para avaliação da ação dos artrópodes predadores, competidores e parasitos da ¿mosca-dos-chifres¿ em fezes bovinas, os ovos das moscas foram inoculados apenas em fezes do grupo não tratado. O número de moscas emergidas das fezes expostas no campo, sob a ação dos insetos da coprofauna bovina, foi significativamente menor (p<0,0021), comparativamente às moscas emergidas das fezes protegidas. Os Dípteros simbovinos no município de Araçatuba, SP, foram similares para os períodos, e entre o grupo tratado e não tratado: Cecidomyidae, Chloropidae, Muscidae, Psychodidae, Sepsidae, Sarcophagidae, Sphaeroceridae e Syrphidae, porém o número, a freqüência, a dominância, a diversidade e a similaridade das famílias, foram influenciadas pelo tratamento / Abstract: The influence of coprophagic insects and the treatment with a anti-helmintic drug (ivermectin) on the development of horn fly (Haematobia irritans) (L.1758), inside bovine feces were evaluated, in Araçatuba county (São Paulo State, Brazil), as well as the influence of these factors on the coprophilic entomofauna. Horn flies and feces were collected in the field from the bovines treated with ivermectin and from untreated bovines (control group). To evaluate the development of these flies in the two groups in conditions of controlled and environmental temperatures the fly eggs were collected, counted and inoculated into bovine feces. The numbers of horn fly that emerged from the feces and the number of larvae primarily inoculated were compared. The untreated group showed a higher number of fly counts, when compared to the treated group (were not observation fly), both in controlled temperature, as well in environmental conditions. The treatment at bovines with ivermectin, performed monthly, prevented the development of horn fly for up to 30 days in all the experiments and, after one treatment with the drug, the flies emerged only on the 28th day. To evaluate the effects of the arthropod predators, competitors and parasites of the horn fly in the bovine feces, flies eggs were inoculated into the feces from the untreated group. The number of flies that emerged from the feces exposed to the field, under the action of coprophilic entomofauna, was significantly smaller (p<0,0001), comparatively to those that emerged from the protected feces. The Diptera associated with bovine dung in Araçatuba municipality, were similar in the treated and untreated groups for studied period: Cecidomyidae, Chloropidae, Muscidae, Psychodidae, Sepsidae, Sarcophagidae, Sphaeroceridae e Syrphidae. However, the total number, frequency, dominance, diversity and the similarities between the families were influenced by the treatment / Doutorado / Doutor em Parasitologia