Variation in Lepidopteran Occurrence in Hemlock-Dominated and Deciduous-Dominated Forests of Central Appalachia

Eastern hemlock, (Tsuga canadensis Carrière, Pinaceae), is threatened with extirpation by an exotic invasive herbivore, the hemlock woolly adelgid, (Adelges tsugae Annand, Homoptera: Adelgidae). Given this threat, a broader and more detailed knowledge of the community associated with eastern hem- lock is merited. As Lepidoptera are important members of forest communities, this study was initiated to determine the relative occurrence of Lepidoptera in hemlock-dominated and deciduous-dominated habitats by evaluating abundance, species richness, temporal variation, and composition overlap. Lepidoptera were surveyed using blacklight traps from May – August 2010 at two collection sites in the Appalachian region of eastern Kentucky. The first collection site was within a forest stand dominated by mixed deciduous species, the second site possessed an overstory of eastern hemlock. Lepidoptera ≥ 20 mm in wingspan were identified and enumerated, yielding a total of 1,020 individuals of ≥ 137 species and 18 families. The total number of Lepidoptera captured in May and June was fewer than in July and August (P ≤ 0.05). The composition of the assemblage varied between collection sites as well as seasonally; 85 species were identified at the deciduous site and 107 species were identified at the hemlock site. While 27 species were recorded only at the deciduous site, 49 species were unique to the hemlock site. Of those unique to the hemlock site, five species were either detritivores or conifer specialists. These data demonstrate the importance of both deciduous and hemlock-dominated forest habitats for many species of Lepidoptera in Appalachia. Our study forms a foundation for understanding species richness patterns of Lepidoptera in hemlock forests in North America and is a useful baseline for comparisons of richness and diversity post invasion by the hemlock woolly adelgid

The Stroboscopic Effect

Consider a straight row of equally spaced white dots on a black belt running at a constant velocity v over two pulleys. Let the dot spacing be D0. Suppose that the belt is in a darkened room so that even when the belt is at rest the dots are invisible. Let the moving belt be periodically illuminated by some source of intermittent and approximately instantaneous illumination of constant frequency B

A Curve of Moisture Condensation on Glass Wool

Experimental results of Professor F. T. Trouton relating to equilibrium vapor pressure and total mass of water vapor fed to glass wool that had previously been thoroughly dried, showed an interesting drop in the curve at about half saturation pressure. The character of the curve appeared to afford grounds for a theory, proposed by Trouton, which supposed the condensation to have taken place in two modes, or states, which he called the alpha and the beta states. After thorough drying, employing the three agencies of continued vacuum, phosphorus pentoxide, and a temperature of about 160°, moisture in the alpha state was supposed to condense on the dried surface first. The alpha condensation required relatively only a small amount of water

The Absence of Liberation or Absorption of Electrons during a Change from the Conduction to the Non-conducting State

Metallic selenium in the crystalline form is an electrical conductor. In the amorphous form, which may be produced by melting a selenium crystal, the substance is an electrical insulator. If, as supposed, electrical conductivity in metals is due to free electrons, then in the change from the conducting to the non-conducting state there must be a disappearance of free electrons. This disappearance could be accounted for by a liberation of electrons into the space surrounding the substance, or by a recombination of free electrons with positive residues to form the neutral molecules of the insulator. In this paper is described an experiment to test the question of liberation of electrons during a change from the conducting to the non-conducting state

The Stroboscopic Effect by Direct Reflection of Light from Vibrating Mirrors.

A very simple and convenient method of producing the stroboscopic effect is to reflect light directly from a vibrating mirror upon a stroboscopic screen. The mirror may be such as is afforded by a vibrating membrane which is itself reflecting or has a suitable mirror attached either directly or indirectly to it

A Table of the Total Number of Stroboscopic Velocity Curves for Any of the Natural Numbers from 1 to 500 Inclusive Taken as a Limiting Value of n and m

The stroboscopic velocity equation is v8 = (A - n/m’B)Do , where n/m is a fraction at lowest terms. Since there are as many stroboscopic velocity curves as there are different values of n/m this fraction may be referred to as the stroboscopic parameter

The Sublimation Curve for Selenium Crystals of the Hexagonal System

The type of apparatus used in the present work on the vapor tension of selenium, as well as the method, is due originally to Knudsen. The apparatus in the form in which Knudsen used it was modified somewhat by Egerton. Egerton\u27s experimental scheme has been followed essentially in the present work

Precontact Conduction Currents

During some work in which capacity measurements were made of plane conducting plates (silver films) in air at very short distances, the writer was able to take some incidental readings of small currents that passed between the plates when they apparently lacked several wave lengths of being in contact. Three sets of measurements were taken in one evening. Figure 1 of figure 38 shows the electrometer deflection plotted with the time. The characteristic shape of the curves suggests an exponential relation