EGGS OF SIALIS (SIALIDAE: MEGALOPTERA) IN EASTERN NORTH AMERICA

1980 ◽  
Vol 112 (4) ◽  
pp. 409-419 ◽  
Author(s):  
L. E. Canterbury ◽  
S. E. Neff

AbstractEgg masses and eggs of Sialis hasta, S. iola, S. joppa, S. infumata, S. aequalis, S. vagans, S. glabella, S. mohri, S. velata, and S. itasca are described using SEM micrographs. Diagnostic characteristics of chorion surface and micropylar structure and a key for specific determination of eggs of these 10 species are given. Oviposition is confined to leaves and twigs near or overhanging water. Eggs are oriented either vertically or horizontally in the egg mass, and hatch in 5 to 10 days in the laboratory. Hatching larvae are aided by an egg burster which tears the chorion and aids in removing the embryonic envelope.

1995 ◽  
Vol 34 (2) ◽  
pp. 297-325 ◽  
Author(s):  
Jeffrey R. Brook ◽  
Perry J. Samson ◽  
Sanford Sillman

Abstract Running 3-day periods from 1979 to 1985 were categorised into one of 20 meteorological categories. These categories were developed through the cluster analysis of 3-day progressions of 85-kPa wind flow over eastern North America. The purpose for developing the categories was to identify recurring atmospheric transport patterns that were associated with differing amounts of wet sulfate (SO2−4) and nitrate (NO−3) deposition at a variety of locations in eastern North America. Identification of these patterns was necessary to facilitate the selection of time periods for simulation by the Regional Acid Deposition Model and in the development of a method for estimating long-term acidic deposition over eastern North America from a limited number of model runs. The effectiveness of this method (referred to as the aggregation method) was expected to be dependent on the ability of the categories to separate structure in wet deposition patterns. This paper describes the determination of the 20 meteorological categories and demonstrates that there were differences in their meteorological and chemical behavior and in their frequency of occurrence. Observations of precipitation and wet SO2−4 and NO−3 deposition from 22 sites in eastern North America and multiple regression models were used to demonstrate that there were statistically significant differences in deposition among categories and that knowledge of meteorological category explained some of the variation in wet deposition. The best statistical correlation, which was based upon precipitation amount, time of year, and meteorological category, explained 35%–83% (28%– 76%) of the observed variation in wet SO2−4 (NO−3) deposition depending on location. On average, across all sites and for both SO2−4 and NO−3, knowledge of category accounted for about 4% of the variation. The minimum amount explained by category was 1% and the maximum was 13%.


Acarologia ◽  
2019 ◽  
Vol 59 (1) ◽  
pp. 57-72
Author(s):  
Gaylord A. Desurmont ◽  
Elven Kerdellant ◽  
Tobias Pfingstl ◽  
Phillipe Auger ◽  
Marie-Stéphane Tixier ◽  
...  

The viburnum leaf beetle Pyrrhalta viburni (Coleoptera: Chrysomelidae) is a specialist Viburnum leaf-feeder that is native to Eurasia and invasive in North America. Eggs of P. viburni are laid in round cavities excavated by the ovipositing female beetle and covered with a protective secretion. We document in this paper the mite fauna associated with P. viburni egg masses on Viburnum tinus in southern France. We then report the results of experiments investigating the seasonal patterns of mite infestation and the effects of the most common mite found within egg masses, Trichoribates trimaculatus (Oribatida: Ceratozetidae), on P. viburni egg survivorship. A diverse mite fauna of 18 species was found on V. tinus twigs, often living within P. viburni egg masses, including predaceous, phytophagous, and detritivorous species. Mite abundance and diversity were higher on Viburnum twigs containing at least one intact egg mass and were positively correlated with the number of intact egg masses per twig. Detritivorous mites were more abundant on twigs nine months after oviposition than one and four months after oviposition. Finally, we found no evidence that T. trimaculatus impacts P. viburni egg survivorship and overwintering success. These findings show that P. viburni egg masses and their associated cavities form a microhabitat favorable for the establishment of several mite species. It seems likely that these associations are cases of commensalism where mites benefit from the presence of food and shelter in these protected cavities, with no direct negative impact on P. viburni eggs.


1986 ◽  
Vol 6 (3) ◽  
pp. 227-243 ◽  
Author(s):  
Andrew L. Christenson

Although the interest in shell middens in North America is often traced to reports of the discoveries in Danish kjoekkenmoeddings in the mid-nineteenth century, extensive shell midden studies were already occurring on the East Coast by that time. This article reviews selected examples of this early work done by geologists and naturalists, which served as a foundation for shell midden studies by archaeologists after the Civil War.


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