Relationship of Horse Fly Host Seeking Activity to the Edge of Wooded Areas in Southern Louisiana

1977 ◽  
Vol 6 (6) ◽  
pp. 781-782 ◽  
Author(s):  
Craig Sheppard ◽  
B. H. Wilson
1991 ◽  
Vol 123 (2) ◽  
pp. 361-370 ◽  
Author(s):  
Paul E.K. McElligott ◽  
Terry D. Galloway

AbstractTwenty species of Tabanidae in three genera [Hybomitra (15 spp.), Tabanus (four spp.), Haematopota (one sp.)] were caught in Manitoba horse fly traps from mid-May to mid-July in 1987, and from mid-May to mid-August in 1988. Hybomitra lurida (Fallen) and H. nitidifrons nuda (McDunnough) peaked in abundance in late May to early June; H. illota (Osten Sacken) and H. lasiophthalma (Macquart) in early June; H. affinis (Kirby), H. arpadi (Szilady), and H. zonalis (Kirby) in mid-June; H. epistates (Osten Sacken) and H. pechumani Teskey and Thomas in late June to early July. Abundance of H. trepida (McDunnough) peaked twice, in late June and early August. Tabanid density and diversity were greatest during June; few flies were present at the site after mid-July. For most species, at the beginning of the flight season, 80–100% of flies dissected were nulliparous. After approximately 1 month of flight activity, parity in all but three species reached levels approaching 100%, and remained high thereafter. Hybomitra lurida and H. nitidifrons nuda were 100% parous within 2 weeks of their first appearance in traps. Parity of H. trepida increased to 100% after 4 weeks, declined to 40% 2 weeks later, and returned to 100% after another 2 weeks.


1964 ◽  
Vol 96 (1-2) ◽  
pp. 166-166 ◽  
Author(s):  
A. J. Thorsteinson ◽  
G. K. Bracken ◽  
W. Hanec

The development of the Manitoba Horse Fly Trap was motivated initially by the need to control tabanid flies in spite of a lack of effective and safe insecticides. This objective could be realized only through a study of orientation behaviour in the field. Starting with the old observation that tabanids are attracted to darkcoloured objects (‘targets’), the influence of colour of target, colour of background, size, shape and movement of target were investigated. The most attractive target proved to be a glossy black (or red) sphere about 24 inches diameter, about three feet above the ground. In the course of its development the trap has provided interesting insights into visual perception of tabanids which will require physiological confirmation. The attractant principle is overwhelmingly visual. An initial surmise that thermal radiation contributes to the attraction significantly has been superseded, although a thermal stimulus may be involved in the behaviour of the flies after they reach the trap. Since only the hemato- phagous sex (females) is attracted to the trap, the behaviour involved appears to be teleologically related to host seeking activity. On arrival at the trap the insects fly in the space around the target and eventually move upward into the no-return chamber at the apex. When the trap is used for fly control the apical chamber is not needed if the interior of the trap is treated with a powerful, residual insecticide. In addition to its potential uses in conjunction with insecticides for control of tabanids, the Manitoba Horse Fly Trap can be used to study the correlation of flight activity with meteorological conditions as well as the seasonal and geographical distribution of tabanid species. The trap can be used effectively in the study of Stomoxys behaviour and control. If the sphere is replaced by a wick containing organic sulfides, blow flies can be attracted to it in considerable numbers.


1991 ◽  
Vol 123 (2) ◽  
pp. 371-378 ◽  
Author(s):  
Paul E.K. McElligott ◽  
Terry D. Galloway

AbstractDaily patterns of host-seeking activity by female tabanids were determined by hourly trapping (0530–2230 hours) with Manitoba horse fly traps at Seven Sisters, Man., 4 days a week, throughout the summer of 1988. Hybomitra epistates (Osten Sacken) and H. pechumani Teskey and Thomas were most active during late morning or mid-day; H. arpadi (Szilady) and H. zonalis (Kirby) in early afternoon; H. affinis (Kirby), H. illota (O.S.), and H. lasiophthalma (Macquart) in late afternoon; H. nitidifrons nuda (McDunnough) and H. lurida (Fallen) in early evening.The morning onset of tabanid flight activity usually was related to temperature, but the cessation of activity in the evening was related either to temperature or light, depending on which was first to fall below threshold levels. Tabanid flight activity was generally low at temperatures below 20°C, although H. lasiophthalma and H. affinis occasionally were caught at 12°C. Little flight activity occurred at light intensity levels below 1000 lx regardless of temperature. At Churchill, Man., where tabanids were trapped hourly from 27 July to 15 August in 1988, H. affinis and H. frontalis (Walker) activity was low below 14°C, although some activity occurred at 6°C.


Paleobiology ◽  
1980 ◽  
Vol 6 (02) ◽  
pp. 146-160 ◽  
Author(s):  
William A. Oliver

The Mesozoic-Cenozoic coral Order Scleractinia has been suggested to have originated or evolved (1) by direct descent from the Paleozoic Order Rugosa or (2) by the development of a skeleton in members of one of the anemone groups that probably have existed throughout Phanerozoic time. In spite of much work on the subject, advocates of the direct descent hypothesis have failed to find convincing evidence of this relationship. Critical points are:(1) Rugosan septal insertion is serial; Scleractinian insertion is cyclic; no intermediate stages have been demonstrated. Apparent intermediates are Scleractinia having bilateral cyclic insertion or teratological Rugosa.(2) There is convincing evidence that the skeletons of many Rugosa were calcitic and none are known to be or to have been aragonitic. In contrast, the skeletons of all living Scleractinia are aragonitic and there is evidence that fossil Scleractinia were aragonitic also. The mineralogic difference is almost certainly due to intrinsic biologic factors.(3) No early Triassic corals of either group are known. This fact is not compelling (by itself) but is important in connection with points 1 and 2, because, given direct descent, both changes took place during this only stage in the history of the two groups in which there are no known corals.


Author(s):  
D. F. Blake ◽  
L. F. Allard ◽  
D. R. Peacor

Echinodermata is a phylum of marine invertebrates which has been extant since Cambrian time (c.a. 500 m.y. before the present). Modern examples of echinoderms include sea urchins, sea stars, and sea lilies (crinoids). The endoskeletons of echinoderms are composed of plates or ossicles (Fig. 1) which are with few exceptions, porous, single crystals of high-magnesian calcite. Despite their single crystal nature, fracture surfaces do not exhibit the near-perfect {10.4} cleavage characteristic of inorganic calcite. This paradoxical mix of biogenic and inorganic features has prompted much recent work on echinoderm skeletal crystallography. Furthermore, fossil echinoderm hard parts comprise a volumetrically significant portion of some marine limestones sequences. The ultrastructural and microchemical characterization of modern skeletal material should lend insight into: 1). The nature of the biogenic processes involved, for example, the relationship of Mg heterogeneity to morphological and structural features in modern echinoderm material, and 2). The nature of the diagenetic changes undergone by their ancient, fossilized counterparts. In this study, high resolution TEM (HRTEM), high voltage TEM (HVTEM), and STEM microanalysis are used to characterize tha ultrastructural and microchemical composition of skeletal elements of the modern crinoid Neocrinus blakei.


Author(s):  
Leon Dmochowski

Electron microscopy has proved to be an invaluable discipline in studies on the relationship of viruses to the origin of leukemia, sarcoma, and other types of tumors in animals and man. The successful cell-free transmission of leukemia and sarcoma in mice, rats, hamsters, and cats, interpreted as due to a virus or viruses, was proved to be due to a virus on the basis of electron microscope studies. These studies demonstrated that all the types of neoplasia in animals of the species examined are produced by a virus of certain characteristic morphological properties similar, if not identical, in the mode of development in all types of neoplasia in animals, as shown in Fig. 1.


Author(s):  
J.R. Pfeiffer ◽  
J.C. Seagrave ◽  
C. Wofsy ◽  
J.M. Oliver

In RBL-2H3 rat leukemic mast cells, crosslinking IgE-receptor complexes with anti-IgE antibody leads to degranulation. Receptor crosslinking also stimulates the redistribution of receptors on the cell surface, a process that can be observed by labeling the anti-IgE with 15 nm protein A-gold particles as described in Stump et al. (1989), followed by back-scattered electron imaging (BEI) in the scanning electron microscope. We report that anti-IgE binding stimulates the redistribution of IgE-receptor complexes at 37“C from a dispersed topography (singlets and doublets; S/D) to distributions dominated sequentially by short chains, small clusters and large aggregates of crosslinked receptors. These patterns can be observed (Figure 1), quantified (Figure 2) and analyzed statistically. Cells incubated with 1 μg/ml anti-IgE, a concentration that stimulates maximum net secretion, redistribute receptors as far as chains and small clusters during a 15 min incubation period. At 3 and 10 μg/ml anti-IgE, net secretion is reduced and the majority of receptors redistribute rapidly into clusters and large aggregates.


Author(s):  
D.L. Spector ◽  
S. Huang ◽  
S. Kaurin

We have been interested in the organization of RNA polymerase II transcription and pre-mRNA splicing within the cell nucleus. Several models have been proposed for the functional organization of RNA within the eukaryotic nucleus and for the relationship of this organization to the distribution of pre-mRNA splicing factors. One model suggests that RNAs which must be spliced are capable of recruiting splicing factors to the sites of transcription from storage and/or reassembly sites. When one examines the organization of splicing factors in the nucleus in comparison to the sites of chromatin it is clear that splicing factors are not localized in coincidence with heterochromatin (Fig. 1). Instead, they are distributed in a speckled pattern which is composed of both perichromatin fibrils and interchromatin granule clusters. The perichromatin fibrils are distributed on the periphery of heterochromatin and on the periphery of interchromatin granule clusters as well as being diffusely distributed throughout the nucleoplasm. These nuclear regions have been previously shown to represent initial sites of incorporation of 3H-uridine.


Author(s):  
Kathleen B. Reuter

The reaction rate and efficiency of piperazine to 1,4-diazabicyclo-octane (DABCO) depends on the Si/Al ratio of the MFI topology catalysts. The Al was shown to be the active site, however, in the Si/Al range of 30-200 the reaction rate increases as the Si/Al ratio increases. The objective of this work was to determine the location and concentration of Al to explain this inverse relationship of Al content with reaction rate.Two silicalite catalysts in the form of 1/16 inch SiO2/Al2O3 bonded extrudates were examined: catalyst A with a Si/Al of 83; and catalyst B, the acid/phosphate Al extracted form of catalyst A, with a Si/Al of 175. Five extrudates from each catalyst were fractured in the transverse direction and particles were obtained from the fracture surfaces near the center of the extrudate diameter. Particles were also obtained from the outside surfaces of five extrudates.


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