Behavioral response of Dendroctonus pseudotsugae and Trypodendron lineatum (Coleoptera: Scolytidae) to selected wavelength regions of the visible spectrum

1981 ◽  
Vol 59 (11) ◽  
pp. 2159-2165 ◽  
Author(s):  
L. J. Groberman ◽  
J. H. Borden
Keyword(s):  
Behavioral Response ◽  
Visible Spectrum ◽  
Secondary Response ◽  
Behavioral Experiments ◽  
Trypodendron Lineatum ◽  
Dendroctonus Pseudotsugae ◽  
Phototactic Response ◽  
Band Pass ◽  
Response Peak ◽  
Walking Bioassay

Behavioral experiments using a phototactic response by adult Dendroctonus pseudotsugae Hopkins and Trypodendron lineatum Olivier were tested in a two-choice, walking bioassay to all possible pairs of a series of wavelengths within the visible spectrum. With Corning band-pass and cut-off filters sensitivity maxima for both sexes of D. pseudotsugae were to the shortest wavelengths (425 and 476 nm), with a secondary response to the longest wavelengths (600–625 nm). With more precise Balzer band-pass filters both D. pseudotsugae and T. lineatum responded similarly, with sensitivity maxima for both sexes to wavelengths in the region of 420–480 nm and an additional response peak around 500–525 nm. These results correspond well with other behavioral and electrophysiological data from scolytid beetles.

Electrophysiological response of Dendroctonus pseudotsugae and Ips paraconfusus (Coleoptera: Scolytidae) to selected wavelength regions of the visible spectrum

1982 ◽  
Vol 60 (9) ◽  
pp. 2180-2189 ◽  
Author(s):  
L. J. Groberman ◽  
J. H. Borden
Keyword(s):  
Fiber Optics ◽  
Spatial Information ◽  
Spectral Response ◽  
Visible Spectrum ◽  
Ips Paraconfusus ◽  
Compound Eyes ◽  
Response Curves ◽  
Dendroctonus Pseudotsugae ◽  
Electrophysiological Response ◽  
Sensitivity Curves

Electroretinograms (ERGs) were recorded from the compound eyes of both sexes of Dendroctonus pseudotsugae Hopkins and Ips paraconfusus (Lanier). Light stimuli between 400 and 650 nm were delivered to the compound eyes through a monochromator connected to a fiber-optics and lens light-delivery system. Stimulus intensity was regulated with neutral density filters. The averaged spectral response curves were similar for both species and sexes. The spectral sensitivity curves disclosed two sensitivity maxima, one in the blue region (450 nm) and one in the green region (510 to 530 nm). These correspond well with behavioural data on scolytids and with response peaks reported in other insects and provide evidence that the scolytid visual system consists of two receptor types. The blue receptors are probably used in navigation during the initial stages of the dispersal flight and the green receptors for the detection of spatial information during host selection.

The responses of miracidia and cercariae of Bunodera mediovitellata (Trematoda: Allocreadiidae) to light and to gravity

1979 ◽  
Vol 57 (3) ◽  
pp. 603-609 ◽  
Author(s):  
Murray James Kennedy
Keyword(s):  
Monochromatic Light ◽  
Larval Stages ◽  
Horizontal Beam ◽  
Phototactic Response ◽  
Glass Tubes ◽  
Vertical Glass ◽  
Response Peak ◽  
Single Response ◽  
Two Peaks ◽  
Vertical Test

Vertical glass tubes, with various portions blackened, were illuminated by a horizontal beam of white light to determine the photoresponse and georesponse of miracidia and cercariae.Four-arm test chambers were used to determine the lowest light intensity at which miracidia and cercariae showed a phototactic response. This intensity (.0.35 lx) was the same for miracidia and cercariae even though miracidia, whose next host is a bottom-dwelling clam (Pisidium casertanum), are photonegative, and cercariae, with a bottom-dwelling caddisfly larva (Limnephilus sp.) as next host, are photopositive.Two-arm test chambers, illuminated with monochromatic light, were used to determine the wavelengths to which the larval stages were responding. Cercariae showed a single response peak at 550 nm while miracidia showed two peaks, one at 550 nm and the other at 650 nm. The second peak may be a result of a screening effect by the pigment which surrounds the photoreceptor.Miracidia showed a positive georesponse when tested in vertical test tubes. However, the negative photoresponse determined their distribution in a conflicting situation. No conclusive results were obtained when the georesponse of cercariae was tested. These larvae remained on the bottom of test chambers under all conditions.

scholarly journals Feel the light – sight independent negative phototactic response in octopus' arms

2021 ◽  
pp. jeb.237529
Author(s):  
Itamar Katz ◽  
Tal Shomrat ◽  
Nir Nesher
Keyword(s):  
Light Beam ◽  
Behavioral Experiments ◽  
Research Results ◽  
Local Activation ◽  
Diverse Species ◽  
Phototactic Response ◽  
Surgical Manipulations ◽  
And Control ◽  
The Brain

Controlling the octopus's flexible hyper-redundant body is a challenging task. It is assumed that the octopus has poor proprioception which has driven the development of unique mechanisms for efficient body control. Here we report on such a mechanism, a phototactic response of extraocular photoreception. Extraocular photoreception has been observed in many and diverse species. Previous research on cephalopods revealed that increased illumination on their skin evokes chromatophore expansion. Recently, the mechanism was investigated and has been termed 'light-activated chromatophore expansion' (LACE). In this work we show that in response to illumination, the arm tip reacts in a reflex-like manner, folding in and moving away from the light beam. We applied a set of behavioral experiments and surgical manipulations to elucidate and characterize this phototactic response. We found that in contrast to the local activation and control of LACE, the phototactic response is mediated by the brain, although it is expressed in a reflex-like pattern. Our research results and observations led us to propose that the phototaxis is a means for protecting the arms in an instinctive manner from potential daytime predators such as fish and crabs, that could identify the worm-like tips as food. Indeed, observation of behaving octopuses revealed that the arm tips are folded-in during the daytime, while at night they are extended. Thus, the phototactic response might compensate for the octopus's poor proprioception by keeping the arms folded in illuminated areas, without the need to be aware of their state.

Field Studies on Flight Patterns and Olfactory Responses of Ambrosia Beetles in Douglas-fir Forests of Western Oregon

1964 ◽  
Vol 96 (10) ◽  
pp. 1339-1352 ◽  
Author(s):  
J. A. Rudinsky ◽  
G. E. Daterman
Keyword(s):  
Field Studies ◽  
The Other ◽  
Seasonal Patterns ◽  
Trypodendron Lineatum ◽  
Dendroctonus Pseudotsugae ◽  
Ambrosia Beetles ◽  
Olfactory Responses ◽  
Temperature Thresholds ◽  
Species Specific ◽  
Sexually Mature

AbstractThe flight of the ambrosia beetles, Trypodendron lineatum (Oliv.), Gnathotrichus sulcatus Lec. and G. retusus Lec., revealed distinct diurnal and seasonal patterns that were influenced by environmental factors, particularly temperature, wind, and daylight. While Trypodendron flies during the entire day when the temperature is favorable, the Gnathotrichus species exhibit a peak of flight at dusk. The temperature thresholds of emergence and initiation of flight for Trypodendron and the threshold for flight of Gnathotrichus were established.The substance responsible for mass attraction of Trypodendron, after the initial invasion of a few pioneer beetles, was found to be a species-specific sex pheromone produced by sexually mature females after entering the host. The pheromone has been concentrated from the female borings in the laboratory, and when released in the field it caused the beetles to respond. Both species of Gnathotrichus, on the other hand, responded to the borings produced by female beetles of Dendroctonus pseudotsugae Hopkins and to the extract prepared in alcohol. This fact suggests possible use of these substances in control of these ambrosia beetles.

Modeling Thin Film Multilayer Broad-Band-Pass Filters in Visible Spectrum

2003 ◽  
Vol 53 (12) ◽  
pp. 1209-1217 ◽  
Author(s):  
M.H. Asghar ◽  
M.B. Khan ◽  
S. Naseem
Keyword(s):  
Thin Film ◽  
Broad Band ◽  
Visible Spectrum ◽  
Band Pass

scholarly journals Allatostatin C/AstC-R2 is a Novel Pathway to Modulate Circadian Activity Pattern in Drosophila

2018 ◽  
Author(s):  
Madelen M. Díaz ◽  
Matthias Schlichting ◽  
Katharine C. Abruzzi ◽  
Michael Rosbash
Keyword(s):  
Locomotor Activity ◽  
Signaling Pathway ◽  
Calcium Imaging ◽  
Activity Pattern ◽  
Behavioral Response ◽  
Ex Vivo ◽  
Circadian Activity ◽  
Behavioral Experiments ◽  
Lateral Posterior ◽  
Circadian Activity Pattern

AbstractSix neuropeptides are expressed within the Drosophila brain circadian network. Our previous mRNA profiling suggested that AllatostatinC is a seventh neuropeptide and specifically expressed in dorsal clock neurons (DN1s). Our results here show that AstC is indeed expressed in DN1s, where it oscillates. AstC is also expressed in two less well-characterized circadian neuronal clusters, the DN3s and lateral posterior neurons (LPNs). Behavioral experiments indicate that clock neuron-derived AstC is required to mediate evening locomotor activity under short (winter-like) photoperiods. The AstC-Receptor 2 (AstC-R2) is expressed in LNds, the clock neurons that drive evening locomotor activity, and AstC-R2 is required in these neurons to modulate the same short photoperiod evening phenotype. Ex vivo calcium imaging indicates that AstC directly inhibits a single LNd neuron. The results suggest that a novel AstC/AstC-R2 signaling pathway, from dorsal circadian neurons to an LNd, regulates the behavioral response to changing photoperiod in Drosophila.

The structure of membranes and membrane proteins embedded in amorphous ice

1992 ◽  
Vol 50 (1) ◽  
pp. 432-433
Author(s):  
Uwe Lücken ◽  
Joachim Jäger
Keyword(s):  
Phase Transition ◽  
Transition Temperature ◽  
Membrane Proteins ◽  
Phase Transition Temperature ◽  
Lipid Vesicles ◽  
Freezing Stress ◽  
Amorphous Ice ◽  
Different Temperatures ◽  
Band Pass ◽  
Lipid Polymorphism

TEM imaging of frozen-hydrated lipid vesicles has been done by several groups Thermotrophic and lyotrophic polymorphism has been reported. By using image processing, computer simulation and tilt experiments, we tried to learn about the influence of freezing-stress and defocus artifacts on the lipid polymorphism and fine structure of the bilayer profile. We show integrated membrane proteins do modulate the bilayer structure and the morphology of the vesicles.Phase transitions of DMPC vesicles were visualized after freezing under equilibrium conditions at different temperatures in a controlled-environment vitrification system. Below the main phase transition temperature of 24°C (Fig. 1), vesicles show a facetted appearance due to the quasicrystalline areas. A gradual increase in temperature leads to melting processes with different morphology in the bilayer profile. Far above the phase transition temperature the bilayer profile is still present. In the band-pass-filtered images (Fig. 2) no significant change in the width of the bilayer profile is visible.

DNA sequence mapping in interphase and metaphase chromosomes by fluorescence in situ hybridization

1992 ◽  
Vol 50 (1) ◽  
pp. 496-497
Author(s):  
Barbara Trask ◽  
Susan Allen ◽  
Anne Bergmann ◽  
Mari Christensen ◽  
Anne Fertitta ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
Dna Sequence ◽  
Dna Sequences ◽  
Dual Band ◽  
Nick Translation ◽  
Metaphase Chromosomes ◽  
Band Pass ◽  
Texas Red ◽  
Fluorescent Spot

Using fluorescence in situ hybridization (FISH), the positions of DNA sequences can be discretely marked with a fluorescent spot. The efficiency of marking DNA sequences of the size cloned in cosmids is 90-95%, and the fluorescent spots produced after FISH are ≈0.3 μm in diameter. Sites of two sequences can be distinguished using two-color FISH. Different reporter molecules, such as biotin or digoxigenin, are incorporated into DNA sequence probes by nick translation. These reporter molecules are labeled after hybridization with different fluorochromes, e.g., FITC and Texas Red. The development of dual band pass filters (Chromatechnology) allows these fluorochromes to be photographed simultaneously without registration shift.

Amplitude Distributions of Cochlear Microphonic Response to an Acoustic Sinusoid in Noise

1968 ◽  
Vol 11 (1) ◽  
pp. 63-76
Author(s):  
Donald C. Teas ◽  
Gretchen B. Henry
Keyword(s):  
Small Amplitude ◽  
Basilar Membrane ◽  
Spectral Composition ◽  
Pass Band ◽  
Cochlear Microphonic ◽  
Filter Output ◽  
Electronic Filter ◽  
Low Pass ◽  
Band Pass ◽  
Instantaneous Voltage

The distributions of instantaneous voltage amplitudes in the cochlear microphonic response recorded from a small segment along the basilar membrane are described by computing amplitude histograms. Comparisons are made between the distributions for noise and for those after the addition to the noise of successively stronger sinusoids. The amplitudes of the cochlear microphonic response to 5000 Hz low-pass noise are normally distributed in both Turn I and Turn III of the guinea pig’s cochlea. The spectral composition of the microphonic from Turn I and from Turn III resembles the output of band-pass filters set at about 4000 Hz, and about 500 Hz, respectively. The normal distribution of cochlear microphonic amplitudes for noise is systematically altered by increasing the strength of the added sinusoid. A decrease of three percent in the number of small amplitude events (±1 standard deviation) in the cochlear microphonic from Turn III is seen when the rms voltage of a 500 Hz sinusoid is at −18 dB re the rms voltage of the noise (at the earphone). When the rms of the sinusoid and noise are equal, the decrease in small voltages is about 25%, but there is also an increase in the number of large voltage amplitudes. Histograms were also computed for the output of an electronic filter with a pass-band similar to Turn III of the cochlea. Strong 500 Hz sinusoids showed a greater proportion of large amplitudes in the filter output than in CM III . The data are interpreted in terms of an anatomical substrate.

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