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Full-Text Articles in Life Sciences

Phenology Of The Western Cherry Fruit Fly (Diptera: Tephritidae) In Utah And Washington, Vincent P. Jones, Diane G. Alston, Jay F. Brunner, Donald W. Davis, Mark D. Shelton Sep 1991

Phenology Of The Western Cherry Fruit Fly (Diptera: Tephritidae) In Utah And Washington, Vincent P. Jones, Diane G. Alston, Jay F. Brunner, Donald W. Davis, Mark D. Shelton

Office of the Dean (CAFES) Scholarship

The flight period of the western cherry fruit fly, Rhagoletis indifferens Curran, was investigated in Utah tart cherry, Prunus cerasus L., orchards from 1983 to 1989 and in Washington sweet cherry, Prunus avium L., orchards between 1982 and 1988. In Utah, flies were first detected on 31 May 1989, but the average time of first detection was 9 June across nine site-years. In Washington, the first fly was detected on 23 May 1988, with an average first detection time of 1 June in the three site-years. On a degree-day (DD) scale (lower threshold of 5°C and no upper threshold), detection …


Ecdysterone Regulatory Elements Function As Both Transcriptional Activators And Repressors., Leonard Dobens, Karen Rudolph, Edward M. Berger Apr 1991

Ecdysterone Regulatory Elements Function As Both Transcriptional Activators And Repressors., Leonard Dobens, Karen Rudolph, Edward M. Berger

Dartmouth Scholarship

A synthetic, 23-bp ecdysterone regulatory element (EcRE), derived from the upstream region of the Drosophila melanogaster hsp27 gene, was inserted adjacent to the herpes simplex virus thymidine kinase promoter fused to a bacterial gene for chloramphenicol acetyltransferase (CAT). Hybrid constructs were transfected into Drosophila S3 cells and assayed for ecdysterone-inducible CAT expression. In the absence of ecdysterone a tandem pair of EcREs repressed the high constitutive level of CAT activity found after transfection with the parent reporter plasmid alone. After hormone addition very high levels of CAT activity were observed. Insertion of the EcRE pair 3' of the CAT gene …


Life History And Descriptions Of Immature Stages Of Tephritis Baccharis (Coquillett) On Baccharis Salicifolia (Ruiz & Pavon) Persoon In Southern California (Diptera: Tephritidae), Richard D. Goeden, David H. Headrick Jan 1991

Life History And Descriptions Of Immature Stages Of Tephritis Baccharis (Coquillett) On Baccharis Salicifolia (Ruiz & Pavon) Persoon In Southern California (Diptera: Tephritidae), Richard D. Goeden, David H. Headrick

Horticulture and Crop Science

Tephritis baccharis (Coquillett) is bivoltine and monophagous on Baccharis salicifolia(Ruiz & Pavon) Persoon in southern California. The egg, the second and third instar larvae, and puparium are described and illustrated. Eggs are inserted singly into terminal buds of main and axillary branches in late winter or early spring. First instar larvae hatch and tunnel into the pith just basad to the apical bud where they initiate gall formation. Gall and larval growth continue slowly into the fall, when pupation occurs. Most F1 flies emerge, mate, and after about one week begin oviposition. Some F1 flies that emerge …


Gelled Diet For Screwworm (Diptera: Calliphoridae) Mass Production, David B. Taylor, Jimmy C. Bruce, Rene Garcia Jan 1991

Gelled Diet For Screwworm (Diptera: Calliphoridae) Mass Production, David B. Taylor, Jimmy C. Bruce, Rene Garcia

Department of Entomology: Faculty Publications

A rearing system based on a diet gelled with Water-Lock G400, a synthetic superabsorbent (poly(2-propenamide-co-2-propenoic acid, sodium salt))( WL), was compared with the standard rearing system (liquid diet suspended in acetate fibers) for the mass production of screwworms, Cochlomyia hominivorax (Coquerel). The WL rearing system yielded 2% heavier pupae, 32% higher egg to pupa survival, and required 54% less diet and 88% less labor than the standard rearing system. Other advantages of the WL system include reduced susceptibility to suboptimal environmental conditions and labor practices, and characteristics conducive to centralization and mechanization of rearing procedures.


Mechanisms Of Hybrid Sunflower Resistance To The Sunflower Midge (Diptera: Cecidomyiidae), Marc D. Anderson, Gary J. Brewer Jan 1991

Mechanisms Of Hybrid Sunflower Resistance To The Sunflower Midge (Diptera: Cecidomyiidae), Marc D. Anderson, Gary J. Brewer

Department of Entomology: Faculty Publications

A study was conducted to identify mechanisms of resistance in sunflower to the sunflower midge, Contarinia schulzi Gagné. Infestation ratings, larval counts, and damage ratings were used to quantify midge resistance in seven sunflower hybrids grown at three locations. Six of the seven hybrids possessed midge resistance. Each hybrid was further categorized with respect to infestation resistance, antibiosis, and tolerance. Two bud characteristics, percent open and size, were examined for their contribution to infestation resistance. The percentage of time that buds of each hybrid were open was negatively correlated with infestation (indicating a preference for the open characteristic). Infestations were …


Oviposition And Larval Bionomics Of Two Weevils (Coleoptera: Curculionidae) On Sunflower, Gary J. Brewer Jan 1991

Oviposition And Larval Bionomics Of Two Weevils (Coleoptera: Curculionidae) On Sunflower, Gary J. Brewer

Department of Entomology: Faculty Publications

Use of cultivated sunflower (Helianthus annum L.) as a host by two species of seed weevils, Smicronyx fulvus LeConte, the red sunflower seed weevil, and S. sordidus LeConte, the gray sunflower seed weevil, was compared using dissection of achenes from naturally and artificially infested plants. The gray seed weevil oviposits on the tips of unopened sunflower florets before anthesis. Larvae migrate through the corolla tube, penetrate the developing achene, and begin extensive feeding at the achene base. Achenes infested by the gray sunflower seed weevil are enlarged, lack an embryo, and appear to be a type of gall. The …


Effect Of Starch-Based Corn Rootworm (Coleoptera: Chrysomelidae) Baits On Selected Nontarget Insect Species: Influence Of Semiochemical Composition, Thomas J. Weissling, Lance J. Meinke, Kandy A. Lytle Jan 1991

Effect Of Starch-Based Corn Rootworm (Coleoptera: Chrysomelidae) Baits On Selected Nontarget Insect Species: Influence Of Semiochemical Composition, Thomas J. Weissling, Lance J. Meinke, Kandy A. Lytle

Department of Entomology: Faculty Publications

Various starch-encapsulated semiochemical-insecticide formulations, developed for potential use in adult corn rootworm (Diabrotica spp.) management programs, were evaluated in the laboratory and field for effectiveness on corn rootworm beetles: a carabid, Harpalus pennsylvanicus DeGeer; and a coccinellid, Coleomegilla maculata lengi Timberlake. Carbaryl was formulated in pregelatinized starch matrices along with Diabroticaspecific semiochemicals. The specific combination of feeding-gustatory stimulants encapsulated within or coating the outside of starch granules significantly influenced effectiveness. Allstarch formulations containing feeding-gustatory stimulants effectively killed Diabrotica virgifera virgifera LeConte adults in laboratory and field bioassays. However, H. pennsylvanicus and C. m. lengi mortality was greatly reduced when …


Potential Of Starch Encapsulated Semiochemical-Insecticide Formulations For Adult Corn Rootworm (Coleoptera: Chrysomelidae) Control, Thomas J. Weissling, Lance J. Meinke Jan 1991

Potential Of Starch Encapsulated Semiochemical-Insecticide Formulations For Adult Corn Rootworm (Coleoptera: Chrysomelidae) Control, Thomas J. Weissling, Lance J. Meinke

Department of Entomology: Faculty Publications

Field and laboratory experiments were conducted from 1987 through 1989 to determine if plant-derived semiochemicals and carbamate insecticides, encapsulated in starch-borate (SBM) and pregelatinized-starch (PGM) matrices, could be used to attract and kill corn rootworm (Diabrotica spp.) beetles. D. virgifera virgifera LeConte adults were concentrated in plots within a corn (Zea mays L.) field, following application of SBM granules formulated with semiochemicals and carbaryl. However, resulting mortality was low even though beetles were observed feeding on the granules. Low mortality levels appear to have been caused by a loss of carbaryl during the formulation process. Laboratory assay results indicated …


Economic Effects Of Horn Fly (Diptera: Muscidae) Populations On Beef Cattle Exposed To Three Pesticide Treatment Regimes, Jerome Hogsette, David Prichard, Joseph Ruff Jan 1991

Economic Effects Of Horn Fly (Diptera: Muscidae) Populations On Beef Cattle Exposed To Three Pesticide Treatment Regimes, Jerome Hogsette, David Prichard, Joseph Ruff

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Horn flies could not be maintained below 50 per animal with sprays or dusts during a 21-wk study. However, weights of cows and calves and condition scores of cows were not influenced by suppression of Haematobia irritans (L.) populations. Results show that cattle in northwest Florida can tolerate average populations of >200 flies for 70 d with no adverse economic effects. Spray treatments providing the best fly control were Lintox-D and Ra-Vap. The most economical products for use were Del-Tox, Lintox-D, and Ra-Vap.