Abundance of Insects Inhabiting the Male Strobili of Red Pine

(excerpt) Southwood (1973) concluded that pollen feeding was probably the first step in the development of the phytophagous habit in insects, because pollen, compared with plant foliage, is rich in nutrients and low in sewndary defense substances. Surprisingly, little is known about insects that feed mainly on pollen. For example, in a bibliography of insects that feed on reproductive structures of North American conifers (Barcia and Merkel, 1972), less than three per cent of 719 references pertained to pollen feeders. This note reports on the kinds and abundance of insects found inhabiting clusters of fresh staminate or male strobili (MS) of 60- to 65-year-old red pine trees in two seed production areas (SPAs) in northern Minnesota

Interview with Karl Mattson, August 10, 2011

Karl Mattson was interviewed on August 10, 2011 by Michael Birkner about his life starting with his earliest memories. This interview is part 1 of a 2 part interview. Length of Interview: 46 minutes Collection Note: This oral history was selected from the Oral History Collection maintained by Special Collections & College Archives. Transcripts are available for browsing in the Special Collections Reading Room, 4th floor, Musselman Library. GettDigital contains the complete listing of oral histories done from 1978 to the present. To view this list and to access selected digital versions please visit -- http://gettysburg.cdmhost.com/cdm/landingpage/collection/p16274coll

Negligible Feeding Responses by Birds to Variations in Abundance of the Budworm, \u3ci\u3eChoristoneura Pinus\u3c/i\u3e (Lepidoptera: Tortricidae)

(excerpts) Recent studies have emphasized that to evaluate the potential importance of any predators in prey regulation it is necessary to consider their functional (feeding) and numerical responses to variations in prey abundance (Holling 1959, Buckner 1966, 1967). For example, preliminary data from a study of bird predation on the jack pine budworm (Choristoneura pinus Freeman) in Michigan indicated that budworm consumption by the common resident birds in jack pine (Pinus banksiana Lambert) forests was only weakly related to observed budworm abundance (Mattson et al. 1968). This note reports further evidence to substantiate the preliminary data

Degree-Day Summation and Hatching of the Forest Tent Caterpillar, \u3ci\u3eMalacosoma Disstria\u3c/i\u3e (Lepidoptera: Lasiocampidae)

(excerpt) The forest tent caterpillar, Malacosoma disstria (Htibner), is a common defoliater of deciduous trees throughout most of the United States and Canada. It is a well known outbreak species, whose populations erupt periodically (every 10 to 16 years) when forest conditions are suitable. Typical outbreaks last three to six years in a given geographic area and then collapse as quickly as they arise. This note documents the relation between forest tent caterpillar egg hatching in the field and heat accumulation (degree-days) leading up to hatch. This information will permit (a) predicting the date on which eggs will hatch by summing degree days during the insect\u27s overwintering period, and (b) comparing with populations in other years and areas. The data came from an outbreak in northern Minnesota that began near International Falls in 1966 and collapsed in 1972 (Witter et al., 1975)

Study to determine an improved method for Apollo propellant system decontamination and propellant tank drying Summary report

Vapor phase cleaning method for Apollo propellant system decontamination and propellant tank dryin

Modified bubble level senses pitch and roll angles over wide range

Bubble level sensor with fiber-optic field flattener is simple, rugged, small, and impervious to temperature and vibration effects. Pitch angles from -15 deg to +40 deg and roll angles of +30 deg are determined within 0.5 deg

RXTE and BeppoSAX Observations of MCG -5-23-16: Reflection From Distant Cold Material

We examine the spectral variability of the Seyfert 1.9 galaxy MCG -5-23-16 using RXTE and BeppoSAX observations spanning 2 years from April 1996 to April 1998. During the first year the X-ray source brightens by a factor of ~25% on timescales of days to months. During this time, the reprocessed continuum emission seen with RXTE does not respond measurably to the continuum increase. However, by the end of the second year during the BeppoSAX epoch the X-ray source has faded again. This time, the reprocessed emission has also faded, indicating that the reprocessed flux has responded to the continuum. If these effects are caused by time delays due to the distance between the X-ray source and the reprocessing region, we derive a light crossing time of between ~1 light day and ~1.5 light years. This corresponds to a distance of 0.001 pc to 0.55 pc, which implies that the reprocessed emission originates between 3x10^15 cm and 1.6x10^18 cm from the X-ray source. In other words, the reprocessing in MCG -5-23-16 is not dominated by the inner regions of a standard accretion disk.Comment: Accepted for publication in ApJ. 17 pages, 8 figure

Epitaxial Growth of an n-type Ferromagnetic Semiconductor CdCr2Se4 on GaAs(001) and GaP(001)

We report the epitaxial growth of CdCr2Se4, an n-type ferromagnetic semiconductor, on both GaAs and GaP(001) substrates, and describe the structural, magnetic and electronic properties. Magnetometry data confirm ferromagnetic order with a Curie temperature of 130 K, as in the bulk material. The magnetization exhibits hysteretic behavior with significant remanence, and an in-plane easy axis with a coercive field of ~125 Oe. Temperature dependent transport data show that the films are semiconducting in character and n-type as grown, with room temperature carrier concentrations of n ~ 1 x 10^18 cm-3.Comment: 12 pages, 3 figure

Adult Female Spruce Bedworm, \u3ci\u3eChoristoneura Fumiferana\u3c/i\u3e (Lepidoptera: Tortricidae), Dry Weight in Relationship to Pupal Fresh Weight and Case Diameter

(excerpt) The weights of adult insects are often measured in production and population studies in order to estimate such variables as growth rates, food conversion efficiencies, fecundity, and others. For the eastern spruce budworm, Choristoneura fumiferana (Clemens), both pupal fresh weights and pupal case diameters have been measured as indicators of adult fecundity and adult dry weights (Miller 1957). However, there are no reports explicitly showing the relationship between these metric pupal variables and adult dry weights. This is the goal of this note

Earth-like sand fluxes on Mars

Strong and sustained winds on Mars have been considered rare, on the basis of surface meteorology measurements and global circulation models, raising the question of whether the abundant dunes and evidence for wind erosion seen on the planet are a current process. Recent studies showed sand activity, but could not determine whether entire dunes were moving—implying large sand fluxes—or whether more localized and surficial changes had occurred. Here we present measurements of the migration rate of sand ripples and dune lee fronts at the Nili Patera dune field. We show that the dunes are near steady state, with their entire volumes composed of mobile sand. The dunes have unexpectedly high sand fluxes, similar, for example, to those in Victoria Valley, Antarctica, implying that rates of landscape modification on Mars and Earth are similar