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Conspicuous Difference (conspicuous + difference)
Selected AbstractsElectrical penetration graphs of the nymphal stage of Bemisia argentifoliiENTOMOLOGIA EXPERIMENTALIS ET APPLICATA, Issue 2 2003Y.X. Jiang Abstract Electrical penetration graph (EPG, DC system) waveforms were recorded from first, second, and third instar Bemisia argentifolii nymphs. Waveforms recorded were similar among the three instars. Four waveforms were recorded and were named C, J, L, and H. Waveform J is new, whereas waveforms C, L, and H of B. argentifolii nymphs were similar to those published previously from greenhouse whitefly nymphs. As in the previous study on greenhouse whitefly nymphs, there was variation in each of waveforms C, L, and H. Waveform C was recorded at an extracellular voltage level, and represents a pathway phase where the stylets penetrate the plant tissue in an intercellular pathway. At the end of waveform C, the voltage dropped to an intracellular level, indicating penetration of a living cell, and the stylet tips then remained in that cell for the rest of the EPG recording, which was sometimes as long as 16 h. Three waveforms (J, L, and H) were recorded during this intracellular phase, beginning with J, a brief (average = 31 s), low amplitude, irregular waveform. J appeared only at the beginning of the intracellular phase, and was followed by either L (five out of eight times) or H (three out of eight times). Waveforms L and H then alternated with one another for the remainder of the intracellular phase. The most conspicuous difference between L and H was the frequency of their voltage fluctuations; L had a lower frequency and H a higher frequency. Usually the shape of waveform L was dominated by voltage peaks in a positive direction, while waveform H was characterized by strong voltage peaks in a negative direction; although some variants of both L and H had distinct voltage peaks in both directions. The electrical origin of both the positive and negative voltage peaks was electromotive force (emf) fluctuation rather than resistance fluctuation. During waveform H, copious amounts of honeydew were produced, indicating that the penetrated cell was a sieve element. We conclude, therefore, that H represents phloem sap ingestion; and because J and L are produced in the same cell as H, then phloem phase is represented by waveforms J, L, and H. The biological correlations for J and L are not yet known. [source] Notes on two species of the subgenus Lyrothorax Chaudoir (Coleoptera: Carabidae; genus Pterostichus), Pterostichus amagisanus Tanaka and Ishida and Pterostichus fujitai Tanaka and IshidaENTOMOLOGICAL SCIENCE, Issue 2 2009Kôji SASAKAWA Abstract Two species of the subgenus Lyrothorax Chaudoir (Coleoptera: Carabidae; genus Pterostichus), Pterostichus amagisanus Tanaka and Ishida and Pterostichus fujitai Tanaka and Ishida, were revised based on the male endophallus (inner sac everted from aedeagus). P. amagisanus was newly recorded based on a single male from Kyushu, southwest Japan, far from its known distribution (Honshu; the Fuji-Hakone-Izu volcano area), although additional materials are necessary to confirm this record. Despite a highly disjunct distribution, no conspicuous difference was recognized in either external or genital characters between the materials from Honshu and Kyushu. The nominal species P. fujitai was separated into two species, P. fujitai (Honshu) and Pterostichus eoyoritomus sp. nov. (Shikoku; type locality: Mount Jingayama); these two species have some significant differences in the endophallic structures. Character states in male genitalia suggest a sister relationship between P. eoyoritomus sp. nov. and Pterostichus yoritomus Bates. [source] On silver wings: a fragile structural mechanism increases plumage conspicuousnessJOURNAL OF AVIAN BIOLOGY, Issue 5 2009Ismael Galván We report for the first time the existence of a structural mechanism of feathers different from iridescence that makes plumage conspicuous. By using electron and light microscopy, we show that the mechanism consists of special lengthened and twisted distal barbules that are very susceptible to damage. The dorsal side of these barbules is translucent, which creates a distinctive sheen colouration to feathers that otherwise would be dark. When distal sheen barbules are broken, the black proximal barbules are exposed, thus generating a conspicuous difference between abraded and non-abraded areas. Total and ultraviolet reflectance of sheen (non-abraded) areas are strikingly higher than in abraded areas. We propose that this mechanism represents a case of convergent evolution in species that are limited in developing colourful plumage patches. Future studies should explore the potential of this colour mechanism to act as a signal of individual quality or identity. [source] Formation of the chondrocranium of Trachemys scripta (Reptilia: Testudines: Emydidae) and a comparison with other described turtle taxaJOURNAL OF MORPHOLOGY, Issue 2 2007Frank J. Tulenko Abstract Few descriptions of the formation of the chelonian chondrocranium exist. Herein, developmental stages critical to the formation of the chondrocranium of the Red-eared Slider, Trachemys scripta (Testudines: Emydidae), are described and illustrated, with particular attention given to ontogenetic changes that take place in the orbitotemporal region of the skull. Morphological descriptions are based on cleared and double-stained and serially-sectioned embryos. These specimens allowed for a detailed evaluation of the developmental morphology of the trabeculae, interorbital septum, pilae metoptica, taeniae marginalis, acrochordal cartilage, pilae antotica, parachordal cartilages, and crista sellaris. Additionally, the formation of the chondrocranium of T. scripta is compared to those of Chrysemys picta (Emydidae) and Caretta caretta (Chelonidae). Overall, the patterns of formation and remodeling of the chondrocranium are quite similar among these species, with the most conspicuous differences observed in remodeling of the posterior orbital cartilages (specifically, the pila metoptica). Reorganization of these cartilages is discussed briefly in the context of associated extraocular muscles for T. scripta and C. caretta. A prominent intertrabecula is reported in T. scripta, supporting previous observations of this structure in emydid turtles. J. Morphol., 2007. © 2007 Wiley-Liss, Inc. [source] |