Insect infestation in museum collections: Organic materials

Author(s):  
N. Valentin
2019 ◽  
Vol 51 (2) ◽  
pp. 251-253
Author(s):  
Elia Guariento ◽  
Filippo Colla ◽  
Michael Steinwandter ◽  
Jiří Háva ◽  
Julia Seeber

The Dermestidae species Attagenus smirnovi Zhantiev, 1973 was discovered in two household in South Tyrol, making it the first official records for this species in Italy. The larvae feeds upon dried organic materials, making this species a common pest in museum collections and households in Central and Northern Europe. The spread of A. smirnovi in Italy was expected but has not yet been recorded. Further, developments of its distribution need to be monitored to prevent damaging infestations, especially to museum collections.


Author(s):  
P.J. Killingworth ◽  
M. Warren

Ultimate resolution in the scanning electron microscope is determined not only by the diameter of the incident electron beam, but by interaction of that beam with the specimen material. Generally, while minimum beam diameter diminishes with increasing voltage, due to the reduced effect of aberration component and magnetic interference, the excited volume within the sample increases with electron energy. Thus, for any given material and imaging signal, there is an optimum volt age to achieve best resolution.In the case of organic materials, which are in general of low density and electric ally non-conducting; and may in addition be susceptible to radiation and heat damage, the selection of correct operating parameters is extremely critical and is achiev ed by interative adjustment.


Author(s):  
M. Iwatsuki ◽  
Y. Kokubo ◽  
Y. Harada ◽  
J. Lehman

In recent years, the electron microscope has been significantly improved in resolution and we can obtain routinely atomic-level high resolution images without any special skill. With this improvement, the structure analysis of organic materials has become one of the interesting targets in the biological and polymer crystal fields.Up to now, X-ray structure analysis has been mainly used for such materials. With this method, however, great effort and a long time are required for specimen preparation because of the need for larger crystals. This method can analyze average crystal structure but is insufficient for interpreting it on the atomic or molecular level. The electron microscopic method for organic materials has not only the advantage of specimen preparation but also the capability of providing various information from extremely small specimen regions, using strong interactions between electrons and the substance. On the other hand, however, this strong interaction has a big disadvantage in high radiation damage.


Author(s):  
J. T. Woodward ◽  
J. A. N. Zasadzinski

The Scanning Tunneling Microscope (STM) offers exciting new ways of imaging surfaces of biological or organic materials with resolution to the sub-molecular scale. Rigid, conductive surfaces can readily be imaged with the STM with atomic resolution. Unfortunately, organic surfaces are neither sufficiently conductive or rigid enough to be examined directly with the STM. At present, nonconductive surfaces can be examined in two ways: 1) Using the AFM, which measures the deflection of a weak spring as it is dragged across the surface, or 2) coating or replicating non-conductive surfaces with metal layers so as to make them conductive, then imaging with the STM. However, we have found that the conventional freeze-fracture technique, while extremely useful for imaging bulk organic materials with STM, must be modified considerably for optimal use in the STM.


1989 ◽  
Vol 4 ◽  
pp. 244-248 ◽  
Author(s):  
Donald L. Wolberg

The minerals pyrite and marcasite (broadly termed pyritic minerals) are iron sulfides that are common if not ubiquitous in sedimentary rocks, especially in association with organic materials (Berner, 1970). In most marine sedimentary associations, pyrite and marcasite are associated with organic sediments rich in dissolved sulfate and iron minerals. Because of the rapid consumption of sulfate in freshwater environments, however, pyrite formation is more restricted in nonmarine sediments (Berner, 1983). The origin of the sulfur in nonmarine environments must lie within pre-existing rocks or volcanic detritus; a relatively small, but significant contribution may derive from plant and animal decomposition products.


2020 ◽  
Vol 22 ◽  
Author(s):  
Shannon L Summers ◽  
Akito Y Kawahara ◽  
Ana P. S. Carvalho

Male mating plugs have been used in many species to prevent female re-mating and sperm competition. One of the most extreme examples of a mating plug is the sphragis, which is a large, complex and externalized plug found only in butterflies. This structure is found in many species in the genus Acraea (Nymphalidae) and provides an opportunity for investigation of the effects of the sphragis on the morphology of the genitalia, which is poorly understood. This study aims to understand morphological interspecific variation in the genitalia of Acraea butterflies. Using specimens from museum collections, abdomen dissections were conducted on 19 species of Acraea: 9 sphragis bearing and 10 non-sphragis bearing species. Genitalia imaging was performed for easier comparison and analysis and measurements of genitalia structures was done using ImageJ software. Some distinguishing morphological features in the females were found. The most obvious difference is the larger and more externalized copulatory opening in sphragis bearing species, with varying degrees of external projections. Females of the sphragis bearing species also tend to have a shorter ductus (the structure that connects the copulatory opening with the sperm storage organ) than those without the sphragis. These differences may be due to a sexually antagonistic coevolution between the males and females, where the females evolve larger and more difficult to plug copulatory openings and the males attempt to prevent re-mating with the sphragis.


2018 ◽  
Vol 45 (2) ◽  
pp. 292-308 ◽  
Author(s):  
Rosi Crane ◽  
B. J. GILL

William Smyth, unable to get work in a New Zealand museum, ran a commercial taxidermy business at Caversham, Dunedin, from about 1873 to 1911 or 1912. His two decades of correspondence with Thomas Frederic Cheeseman at the Auckland Museum provide a case study of Smyth's professional interaction with one of New Zealand's main museums. We have used this and other sources to paint a picture of Smyth's activities and achievements during a time when there was great interest in New Zealand birds but few local taxidermists to preserve their bodies. Besides the Auckland Museum, Smyth supplied specimens to various people with museum connections, including Georg Thilenius (Germany) and Walter Lawry Buller (New Zealand). Smyth was probably self-taught, and his standards of preparation and labelling were variable, but he left a legacy for the historical documentation of New Zealand ornithology by the large number of his bird specimens that now reside in public museum collections in New Zealand and elsewhere.


Sign in / Sign up

Export Citation Format

Share Document