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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Morfologia e desenvolvimento do sistema reprodutor em três espécies de Isoptera

Laranjo, Lara Teixeira [UNESP] 07 April 2015 (has links) (PDF)
Made available in DSpace on 2016-02-05T18:29:40Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-04-07. Added 1 bitstream(s) on 2016-02-05T18:33:42Z : No. of bitstreams: 1 000856124.pdf: 11363241 bytes, checksum: 5694d744ff9f5ee6e389521c65f65370 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Reis de Isoptera fornecem grandes quantidades de espermatozoides viáveis à rainha. Contudo, o estudo do sistema reprodutor dos machos destes insetos tem sido negligenciado quando comparado ao das fêmeas. Com o objetivo de suprir essa lacuna, a presente pesquisa visou um estudo comparativo do sistema reprodutor em diferentes idades desses machos, incluindo ninfas e reprodutores alados. Desse modo, foram escolhidas três espécies, pertencentes a três famílias que ocupam posições evolutivas diferentes: Cryptotermes brevis, Coptotermes gestroi e Silvestritermes euamignathus. No Capítulo I, foi dado destaque à produção de espermatozoides e desenvolvimento das vesículas seminais em ninfas de último ínstar, reprodutores alados e reis com 6 meses e 1 ano de idade de C. brevis. Nas ninfas, os espermatozoides estão restritos aos testículos. O Capítulo II enfoca principalmente a histoquímica e ultraestrutura das vesículas seminais de C. gestroi e assinala o início da espermatogênese em ninfas de 3º ínstar, apesar de ninfas de 5º ínstar ainda não estocarem espermatozoides nas vesículas seminais. Nesta espécie, as vesículas seminais individualizadas apresentam uma região distal secretora e uma região proximal com função de armazenamento de espermatozoides. Adicionalmente, a histoquímica evidenciou polissacarídeos e proteínas na secreção presente na região distal destas estruturas. No Capítulo III, foi acompanhada a evolução do aparelho reprodutor em machos de S. euamignathus. Os resultados mostraram um amadurecimento precoce do sistema reprodutor dos machos e um aumento da produção de espermatozoides em reis de colônias maduras. Além disso, as vesículas seminais aumentaram muito nestes indivíduos e se apresentaram como porções especializadas dos dutos deferentes. Adicionalmente, dados morfológicos e histoquímicos permitem inferir que as vesículas seminais de reis funcionam mais como órgão de... / Kings of Isoptera supply large quantities of viable sperm to the queens. Nevertheless, the study of the male reproductive system of these insects has been neglected when compared to that of females. In order to fill this gap, this research aimed a comparative study of the reproductive system in different ages of termite males, including nymphs and winged reproductives. Thus, three species were chosen from three families that have different evolutionary positions: Cryptotermes brevis, Coptotermes gestroi and Silvestritermes euamignathus. Chapter I emphasized the production of sperm and development of seminal vesicles in last instar nymphs, alates and 6-month and 1-year-old kings of C. brevis. In nymphs, the sperm are restricted to the testicles. Chapter II focuses primarily on the histochemistry and ultrastructure of the seminal vesicles of C. gestroi and records the beginning of spermatogenesis in 3rd instar nymphs, even though 5th instar nymphs have not stored sperm in the seminal vesicles. In this species, individualized seminal vesicles have a secretory distal region and a proximal region with sperm storage function. In addition, the histochemistry showed polysaccharides and proteins present in the secretion of these structures at the distal region. In Chapter III, the evolution of the reproductive system in male of S. euamignathus was followed. The results showed an early maturation of the reproductive system of males and the increasing sperm production in kings of mature colonies. Additionally, morphological and histochemical data allowed us to infer that the seminal vesicles of kings function more likely as a sperm storage organ than secretory structures. Chapter IV is dedicated to an analysis of the gonads of replacement reproductives, which were collected in three different colonies of C. brevis. Colonies A and B were formed by a couple containing a neotenic and a primary reproductive. The primary king and the neotenic king showed ... / FAPESP: 11/10590-4
42

Laboratory and Field Studies on Subterranean Termites Native to the Eastern United States

Little, Nathan Shook 01 May 2010 (has links)
This study investigates modifications to AWPA Standard E18-06 to develop an above-ground field test for subterranean termites native to the eastern United States. AWPA Standard E18-06 was modified in two stages to progressively increase optimum conditions for subterranean termite feeding. Modification II, which incorporated the use of house bricks and feeder strips with a solid ventilated cover, had an increase in termite attack with less variation between tests. This study also investigates the effects of adding antioxidants, both natural and synthetic, and analogues which lack antioxidant properties, to test wood blocks on feeding by Reticulitermes flavipes Kollar using AWPA Standard E1-09. Antioxidants had feeding deterrence and mortality properties to R. flavipes. Conversely, the non-antioxidant analogues, with the exception of the heterocyclic flavanone, had little effect on R. flavipes. It is concluded that R. flavipes instinctively avoids wood which contains high levels of antioxidants, such as heartwood with phenolic extractives.
43

Evaluation des perturbations de l'oléoduc Tchad-Cameroun sur les assemblages de termites

Akama, Pierre 20 December 2012 (has links)
Les perturbations sont des événements séparés dans le temps qui modifient une population, un écosystème ou un paysage, en changent la structure, le milieu physique et le fonctionnement. Ces événements font partie intégrante de la dynamique des écosystèmes, mais les hommes en ont changé le régime par l’agriculture, les travaux de génie civil, etc. Elles sont devenues une menace pour la biodiversité. C’est ainsi qu’une étude a été menée pour évaluer l’influence du projet de pipeline Tchad-Cameroun sur les assemblages de termites, cinq ans après son achèvement.<p>Les recherches ont été menées dans les écosystèmes de savane et de forêts camerounaises via deux méthodes d’échantillonnage. La méthode des transects belts d’Eggleton et Jones (2000) a permis de collecter 99 espèces de termites (36 transects dans 4 écosystèmes) ;en complément à celle-ci, la méthode quantitative des carottages de Wood et Sands (1978) a permis de récolter 70 espèces de termites (480 carottes). La différence de richesse spécifique résulte du sous échantillonnage par la méthode des carottages parce que certains habitats susceptibles d’abriter des termites ne sont pas explorés.<p>Les résultats obtenus montrent que l’infrastructure a perturbé sensiblement les paramètres texturaux, la densité apparente, les propriétés hydriques et la matière organique du sol. Il a diminué la richesse spécifique globale des termites, et essentiellement celle des humivores. Il a augmenté la densité des termites du groupe II et diminué celle des termites du groupe IV mais la densité globale des termites n’a pas été modifiée. En fait, les milieux témoins que nous avons échantillonnés étaient déjà moyennement dégradés avant la pose de l’oléoduc.<p>L’étude de l’évolution de la litière de Milicia excelsa en litter bags a permis de montrer que ni le l’infrastructure ni la variabilité des écosystèmes n’exercent un effet sur la vitesse de décomposition de cette litière ;en revanche, la dimension de la maille, autorisant ou non le passage des termites, a montré que ceux-ci interviennent pour environ 20 % dans la perte de masse de la litière.<p>L’apport expérimental d’infusions à base de Chromolaena odorata et d’Alchornea cordifolia a sensiblement abaissé le rapport C/N du sol mais n’a eu qu’un effet très limité sur les assemblages de termites.<p> / Doctorat en Sciences / info:eu-repo/semantics/nonPublished
44

Termite control strategies of heritage buildings: with case studies of Hong Kong SAR

曹永賢, Tso, Wing-yin, Paul. January 2005 (has links)
published_or_final_version / Conservation / Master / Master of Science in Conservation
45

Arizona Termites of Economic Importance

Baker, Paul B., Marchosky, Ruben 06 1900 (has links)
20 pp.
46

FORAGING PARTY AND TERRITORY SIZE OF THE DESERT SUBTERRANEAN TERMITE HETEROTERMES AUREUS (SNYDER) IN A SONORAN DESERT GRASSLAND (ARIZONA).

JONES, SUSAN CATHERINE. January 1987 (has links)
Foraging party and territory size of Heterotermes aureus (Snyder) were investigated on the Santa Rita Experimental Range south of Tucson, Arizona. A comparison of three techniques for delineating territorial extent suggested that the release and recapture of dyed termites was most useful, while agonistic behavior among termites may reflect past as well as current associations. Spatial and temporal patterns of termite attack on baits proved to be unreliable. Data obtained via the release and recapture of dyed termites indicated that most territories encompassed an area of several hundred to thousand square meters. These data sharply contrast with those obtained via spatial and temporal patterns of termite attack, which provided an estimate of 9.2 m² for average territory size. Although agonistic responses were useful for differentiating H. aureus colonies, the lack of this behavior among termites did not necessarily imply a current relationship, as they may have been from subgroups that previously had budded off from each other. These groups may be headed by neotenic reproductives, which were found for the first time under field conditions for this species. Data on foraging party size obtained via a mark-release-recapture technique indicated that many H. aureus colonies contained from ca. 50,000 to 300,000 foragers. However, the validity of these estimates is suspect because several of the assumptions of this technique were not met, i.e., marked individuals did not completely mix in the population, but their numbers tended to be more concentrated near release sites, and colonies may have represented open populations. However, exhaustive trapping data also indicated that colonies may contain tens or hundreds of thousands of foragers. As many as 100,000 foragers in a single colony were removed from fiberboard traps during a 1.5-year period. The average foraging party consisted of 1,456 individuals, of which 8.6% were soldiers.
47

Subterranean termite infestation of urban structures in the Tucson basin: Patterns and influences.

Colwell, Curt Edward. January 1987 (has links)
A three-part study was conducted to characterize and assess the impact of subterranean termite infestation of urban structures in Tucson, Arizona. A termite control questionnaire was administered to all Tucson-based pest control firms offering termite control services, of which 52 percent responded. Twelve study sites were established in and around the city, with toilet paper rolls serving as termite bait at each site. In addition, 5943 active termite control contracts were accessed from Tucson's largest pest control company, and analyzed with accompanying data from various sources including those pertinent to structure location, construction, treatment history, and surrounding soil types. An estimate of over $3 million for gross annual income derived from commercial termite control services performed in Tucson, was calculated from questionnaire responses. Termide (heptachlor + chlordane) was the most frequently used termiticide. Approximately 45 percent of commercial termite control jobs were performed with Termide, the principal termiticide used by 85.7 percent of companies offering termite control services. Gnathamitermes perplexus (Banks) was most prevalent in the toilet paper rolls at bait sites, followed by Heterotermes aureus (Snyder) and Reticulitermes tibialis Banks. G. perplexus infested bait at sites that resembled the surrounding desert while H. aureus and R. tibialis generally infested those which had been significantly altered by irrigation and landscaping. H. aureus and, to a lesser degree, R. tibialis, are by far the most economically important of the 18 termite species inhabiting Tucson and the surrounding area. Significant interrelationships were found between termite contract density, customer affluence, housing density, structure age, and soil permeability, and also between retreatment rate, foundation type, and materials used in wall construction. The percentage of structures under contract requiring retreatment was estimated to be between 17.3 percent and 42.7 percent per year. Analysis utilizing termite control contracts is suggested as a unique and effective approach providing critical insight into factors influencing termite communities and patterns of infestation in the urban environment.
48

Forest conversion to smallholder plantations : the impacts on soil greenhouse gas emissions and termite diversity in Jambi, Sumatra

Aini, Fitri Khusyu January 2016 (has links)
Ongoing conversion of forests in Sumatra to agricultural lands might affect the biodiversity of soil fauna, such as termites, and emissions of nitrous oxide (N2O), methane (CH4) and carbon dioxide (CO2). To assess the impact of such forest conversions, this study was conducted in Jambi, Sumatra in an undisturbed forest (FR), a disturbed forest (DF), a one year old rubber plantation (RB1), a twenty year old rubber plantation (RB20) and an oil palm plantation (OP). The plantations belonged to smallholders and were not usually fertilized. The effect of fertilizer was assessed by applying N fertilizer and taking a series of intensive measurements. The N2O, CH4 and CO2 fluxes were measured using static chamber methods and termite species richness was assessed using a standard semi quantitative transect method. Forest conversion to smallholder plantations did not significantly affect the N2O, CH4 and CO2 fluxes, but the diversity and relative abundance of termites was decreased. this implies that the ecosystem services regulated by termites might decline. The application of N fertilizer at the conventional rate (141 kg N ha-1 y-1), with an emission factor of 3.1 % in the oil palm plantation, increased N2O emissions to twice as high as that in the undisturbed forest. The annual N2O and CH4 fluxes from termites amounted to 0.14, 0.21, 0.88, 2.47 and -0.56 kg ha-1 y-1 N2O-N and 0.85, 1.65, 3.80, 0.97 and 2.30 kg ha-1 y-1 CH4-C in the FR, DF, RB1, RB20 and OP, respectively. Further research is needed to understand the interannual variability of the N2O, CH4 and CO2 fluxes from soils and termites. Understanding the key drivers and underlying processes which regulate them would help to control the biodiversity loss and the change of N2O, CH4 and CO2 fluxes from soils and termites.
49

Revisão taxonômica do gênero Spinitermes Wasmann, 1897 (Isoptera, Termitidae, Termitinae) / Taxonomic revision of the termite genus Spinitermes Wasmann, 1897 (Isoptera, Termitidae, Termitinae)

Carrijo, Tiago Fernandes 08 May 2009 (has links)
Esta dissertação trata da revisão taxonômica do gênero sul-americano Spinitermes Wasmann, 1897 (Isoptera, Termitidae, Termitinae). Estudei um total de 399 amostras, incluindo todas as do MZUSP e as de outras instituições, das quais solicitei material emprestado. As espécies deste gênero ocorrem no solo e em ninhos epígeos de outras espécies de cupins, principalmente do gênero Cornitermes (Termitidae, Syntermitinae), e alimentam-se de material orgânico em decomposição. De acordo com os caracteres morfológicos, separei as seis espécies já descritas e três espécies novas em três grupos: Grupo allognathus, com Spinitermes allognathus, S. sp. A, sp.n. e S. sp. B, sp.n., Grupo robustus, com S. robustus e Grupo trispinosus, que ainda dividi em dois subgrupos, de acordo com as características das válvulas entéricas, com Subgrupo de V.E. lisa (S. longiceps, S. nigrostomus, S. trispinosus e S. sp. C, sp.n.) e Subgrupo de V.E. rugosa (S. brevicornutus). Fiz as descrições de todas as castas dos três grupos e diagnoses para as espécies e subgrupos. Ilustrei o soldado de todas as espécies e os imagos conhecidos. Também ilustrei os seguintes caracteres dos operários de cada um dos grupos: pronoto, mandíbulas, gálea, lacínia, tubo digestivo in situ, válvula entérica e moela. Apresento uma chave dicotômica para identificação das espécies baseada em soldados e mapas de distribuição geográfica para todas as espécies. / This is the taxonomic revision of the South American genus Spinitermes Wasmann, 1897 (Isoptera, Termitidae, Termitinae). I studied 399 samples including all those from MZUSP and others from institutions that I requested material as loans. The species of this genus feed on decomposed organic matter and occurs in both the soil and in the epigeal nests constructed, mainly, by species of the genus Cornitermes (Termitidae, Syntermitinae). Using morphological characters, mainly from soldiers, I clustered the six species already known and the three new ones into three groups: Grupo allognathus: Spinitermes allognathus, S. sp. A, new species and S. sp. B, n.sp.; Grupo robustus: S. robustus; and Grupo trispinosus, that I subdivided, accordantly to the enteric valves characteristics, into two subgroups: Subgrupo de V.E. lisa: S. longiceps, S. nigrostomus, S. trispinosus and S. sp. C, n.sp., and Subgrupo de V.E. rugosa: S. brevicornutus. I described all castes of the three groups and made diagnoses for the species and subgroups; I also made illustrations of the soldier and imago, when presents, for all species and the pronote, mandibles, galea, lacinia, digestive tube in situ, enteric valve and crop from workers of the three groups. In addition, I present a dicotomic key for identification of the species using soldiers and geographic distributions maps for all species.
50

Abundance and distribution of Microtermes (Isoptera: Termitidae: Macrotermitinae) in cultivated and uncultivated areas at Mokwa in the Southern Guinea savanna vegetation zone of Nigeria

Black, Helaina I. J. January 1994 (has links)
Population dynamics of Microtermes (Isoptera; Macrotermitinae) are investigated in the Southern Guinea savanna vegetation zone of Nigeria. Study sites were primary woodland, long-term maize and a randomised block experiment established from secondary woodland with woodland, pasture, sweet potato, groundnuts, yam and maize. The species assemblage Comprised of Microtermes allleo, Microtermes n.sp. c., Microtermes grassei, Microtermes/epidus, Microtermes subhyalinus. 2 Microtermes abundance and distribution (n/m2) to a soil depth of 1 metre are examined in Chapter Four. Community structure differed with vegetation cover. Abundance was generally higher in the wet compared to the dry season and abundance.was greatest in long-term maize and higher in newly cleared and cultivated sites than in woodland. M subhya/inus was the most abundant species in all vegetation types except long-term cultivated maize where M /epidus was the most abundant species. Changes in crop alter species abundance and Microtermes community structure. Microtermes fungus comb abundance (n/m2), individual dry weight (g) and total dry weight (g/m2) to a soil depth of 1 metre in primary and secondary woodland and short and long-term maize are examined in Chapter Five. Vegetation cover had an influence on seasonal changes in the abundance, individual and total dry weights of fungus combs. M subhyalinus fungus combs showed the greatest seasonal changes, in secondary woodland and short-term maize. Microtermes foraging activity on softwood baits with season, species and vegetation is examined in Chapter Six. Seasonal differences in foraging activity were recorded but differences over time were more significant. Foraging activity differed with vegetation and species. Percentage of baits attacked by species as a proportion of the total number of baits attacked by all species was the best indicator of foraging activity. Non-random foraging was identified for Microtermes with positive associations among M. subhya/inus, M. aluco and M. lepidus. Microtermes foraging activity on baits is compared with soil abundance in Chapter Seven using diversity indices and simple linear regression analysis. Foraging activity can give a more accurate indication of species richness than soil sampling. Foraging activity can be correlated positively with soil abundance, most significantly with wet season assessments.

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