• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 1027
  • 170
  • 170
  • 170
  • 170
  • 170
  • 168
  • 168
  • 96
  • 76
  • 30
  • 24
  • 11
  • 8
  • 5
  • Tagged with
  • 1955
  • 583
  • 433
  • 193
  • 187
  • 170
  • 151
  • 147
  • 144
  • 140
  • 126
  • 104
  • 102
  • 100
  • 87
  • 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.
201

The effects of Altosid®, a juvenile hormone analogue, on the development of Tribolium castaneum, Tribolium confusum, Tribolium audax, and Tribolium madens

Taylor, Clark 01 January 1976 (has links)
No description available.
202

Myotropic peptide hormones and serotonin in the regulation of feeding in the adult blow fly Phormia regina, and the adult horse fly Tabanus nigrovittatus

Haselton, Aaron T 01 January 2005 (has links)
The act of feeding and all subsequent post-ingestive physiological processes requires the strict control and coordination of many body systems, often by neuropeptides and biogenic amines. In this study, the roles of two classes of neuropeptides, the FMRFamide related peptides (FaRPs) and the tachykinin related peptides (TRPs), and the biogenic amine serotonin were examined as they relate to alimentary function and feeding behavior in both the adult, female blow fly, P. regina, and the adult, female horse fly, Tabanus nigrovittatus. FMRFamide-like immunoreactivity (FLI) and locustatachykinin-like immunoreactivity (LTKLI) was observed throughout nervous and alimentary tissues in both flies using whole mount immunofluorescence and paraffin section immunohistochemical techniques. The observed immunolocalization suggests that both peptide classes are brain gut peptides in these two flies. Immunoreactivity was fairly well conserved between these two flies despite their divergent anatomy. The TRP callitachykinin-I (Cav TK-I) was found to have myotropic effects on in vitro P. regina crop preparations. Exogenous Cav TK-1 simultaneously relaxed the distal lobes of the crop sac while increasing contractions in the crop “pump” region of the crop. Serotonin like immunoreactivity (SLI) was observed throughout the nervous system and alimentary tract in T. nigrovittatus. A dense network of SLI processes covered the surface of the midgut, suggesting an important role for serotonin in midgut activity. T. nigrovittatus injected with 50 μg of the serotonin depleter α-methyltryptophan (AMTP) were more likely to blood-feed than saline injected flies. To investigate the role of serotonin in feeding in P. regina , flies were injected with serotonin and allowed to feed on liver homogenate. Flies injected with 50 μg of serotonin ingested less liver than control flies at 1, 3, 6, and 24 h post-injection and also exhibited increased body weight loss at the 3, 6, and 24 h post-injection time intervals.
203

Genetic basis of pheromone-mediated sexual communication in the pink bollworm moth, Pectinophora gossypiella (Lepidoptera: Gelechiidae)

Collins, Robert D 01 January 1988 (has links)
Long distance sexual communication in the pink bollworm moth, Pectinophora gossypiella, is based on a female-emitted two-component pheromone ((Z,E)- and (Z,Z)-7,11-hexadecadienyl acetate). The genetic bases of pheromone production and response were examined to assess the potential for the development of resistance to synthetic pheromone used as a mating disruptant. Male response was measured with a still-air wing-fanning bioassay. Heritability (h$\sp2$) of wing-fanning duration was significant for 25 and 44% ZE blends (h$\sp2$ = 0.377 $\pm$ 0.113 and 0.385 $\pm$ 0.095, respectively) but not for a 65% ZE blend (h$\sp2$ = $-0.145\ \pm$ 0.103). Solvent extracts of excised pheromone glands were used to measure pheromone production by females. Heritabilities for pheromone blend and amount were 0.342 $\pm$ 0.08 and 0.410 $\pm$ 0.089, respectively. Selection of females producing pheromone with a higher percentage of the ZE isomer resulted in an increase in mean ($\pm$ SD) blend from 42.9 $\pm$ 1.0 to 48.23 $\pm$ 1.2% ZE after 12 generations. Although significant, this change is small compared to the broad male response spectrum, and may be insufficient for the evolution of resistance to synthetic pheromone. The duration of wing fanning to blends with a high percentage of the ZE isomer was elevated in the female-selected line, demonstrating that signal production and response are influenced by the same or closely linked loci. Selection for females that produce more pheromone resulted in a rapid increase in pheromone titer (24.0 $\pm$ 8.1 to 45.8 $\pm$ 7.9 ng in 6 generations). Selection for greater male responsiveness to a 44% ZE blend yielded an increase in wing-fanning duration from 5.36 $\pm$ 13.65 to 17.40 $\pm$ 26.98 sec after 6 generations. Based on these selection responses, evolution of resistance appears more likely through a change in pheromone amount than through a change in the pheromone component ratio.
204

Investigations into mating disruption, delayed mating, and multiple mating in oriental beetle, Anomala orientalis (Waterhouse), Coleoptera: Scarabaeidae

Wenninger, Erik J 01 January 2005 (has links)
Oriental beetle, Anomala orientalis (Coleoptera: Scarabaeidae) is a pest of turf, ornamentals, and several crops, including cranberry; damage is caused by larval feeding on plant roots. Imidacloprid---the only new pesticide registered against scarabs in cranberry since the ban on organochlorines in the 1970s---is expensive and relatively ineffective against later instar larvae. I evaluated the potential management of oriental beetle in cranberry by mating disruption using female sex pheromone deployed from wax disks. I found strong trap shutdown in mating disruption treatments. Because attempts to disrupt mating may be compromised if males eventually find females, I studied the effects of delayed mating on female reproductive output in the lab. Females were relatively resilient to mating delay, exhibiting only a gradual decline in fecundity with increased age at mating. Thus, in order for mating disruption to be a successful management tool, mating must be prevented rather than delayed. I deployed tethered virgin females deployed in the field and found that mating is indeed largely prevented in pheromone-treated bogs. These results demonstrate the strong potential of mating disruption for management of oriental beetle in cranberry. I also studied relative fertilization success between males in successive matings of the same female. Characters of the first male to mate---including male body size and genitalia morphology---had primacy in influencing relative paternity, an uncommon pattern in sperm precedence studies. Surprisingly, relative paternity of the first male was inversely correlated with his size. Because this result is at odds with the general positive relationship between male size and reproductive success in insects, I hypothesized that larger males experience greater lifetime reproductive success when mating multiply. I then examined how male size and mating history impacted reproduction. Only for smaller males was reproductive output reduced in successive matings. These results suggest that after their first mating, smaller males must either compete using a lower quality ejaculate or submit to a longer refractory period to replenish ejaculate reserves. Thus, the sexually selected advantage of smaller males in their first mating is apparently balanced by lower lifetime reproductive potential relative to larger males.
205

Management of Tuta absoluta in Kenya

Nyamu, Denis Gachau January 2020 (has links)
No description available.
206

Fluctuations of the Clover Seed Chalcid, Bruchophagus gibbus (BOH.), and Other Alfalfa Insect Populations in Cache Valley, Utah During the Summer of 1958

Tilley, Keith C. 01 May 1960 (has links)
The clover seed chalcid Bruchophagus gibbus as it is presently classified, was originally described by Howard, in 1879 as Eurytoma funebris Howard. Kolobova reported different races of chalcid on clover and alfalfa in Russia. Studies are presently being conducted in the United States to see if these are applicable to our fauna.
207

Molecular interactions of brown marmorated stink bug, Halyomorpha halys with its bacterial endosymbiont, Pantoea carbekii and their role in nutrient provisioning

Mittapelly, Priyanka January 2018 (has links)
No description available.
208

A systematic study of the external male genitalia of the Genus Septis (Lepidoptera Phalaenidae).

Hardwick, David Francis. January 1948 (has links)
Typewritten mss.
209

A comparative study of two sympatric species of field cricket, Gryllus pennsylvanicus Burmeister and G. Veletis (Alexander and Bigelow) (Orthoptera: Gryllidae).

Rakshpal, Ram. January 1961 (has links)
No description available.
210

Occurrence of the Swaine jack-pine sawfly and external anatomy of the mature, feeding larvae.

Wallace, Donald. R. January 1959 (has links)
No description available.

Page generated in 0.0492 seconds