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The ED50 of a strain of Serratia marcescens for microinjected instar III and IV gypsy moth larvae was 7.5 and 14.5 viable cells, respectively. Percentage and rate of mortality were found to be highly variable among replicates of the same instar and between instars in free-feeding bioassays. Mortality in second instar larvae occurred before ecdysis, whereas practically no mortality occurred in third and fourth instars until the molting period. Neither Boivin endotoxin preparations nor culture filtrates were toxic to instar III larvae when administered per os or by microinjection. Histological evidence indicated that the microorganism invaded the hemocoel of healthy or predisposed insects through the gut wall. The rapid multiplication of the bacterium in the hemocoel of infected insects, followed by death in the absence of extensive tissue damage, indicated mortality was due to a septicemia. The histological and biological evidence presented indicated that the microorganism would be less than effective if utilized as a conventional microbial insecticide. © 1976.

A gram-negative bacillus, pathogenic for gypsy moth larvae, was characterized culturally, morphologically, and physiologically as a member of the Serratia group of the family Enterobacteriaceae. The microorganism lacked the pigmentation characteristic of the group but was generally distinguished from closely related members of the family by its inability to produce gas from glucose, inositol, glycerol, and cellobiose; its rapid liquefaction of gelatin; and its failure to ferment raffinose or arabinose. The microorganism displayed lecithinase, deoxyribonuclease, and chitinase activity. The percentage of G + C in DNA from this bacterium was within the range reported for known strains of Serratia marcescens. © 1976.

1. 1. The influence of thermal acclimation on cable constants of the median giant axon of earthworms, Lumbricus terrestris L., has been studied using standard intracellular stimulating and recording techniques. 2. 2. Acute cooling of axons from warm-acclimated worms resulted in changes in cable constants, some of which were partially compensated for (reversed) after cold acclimation. 3. 3. Of special interest is the relative behavior of specific axoplasm resistance in response to acute temperature change in warm- and cold-acclimated worms. 4. 4. The results suggest that thermal acclimation alters the properties of the axoplasm and that the resulting changes in cable constants contribute to compensatory adjustments in nerve conduction velocity after acclimation. © 1973.

Growth and survival of scaled sardine, Harengula pensacolae, larvae were evaluated in laboratory rearing experiments at temperatures ranging from 21 to 35 C. Fertilized eggs were obtained in plankton collections made near Miami, Florida, in summer 1971. Larvae were reared for 15 days after hatching in temperature-controlled, 75-liter aquaria. Hatching success was high at all temperatures but larvae did not survive at 35 C, and survival was poor at 21-23 C. Survival was best at temperatures between 26 and 32 C. Mean daily growth increments ranged from 0.056 mm at 21-23 C to 1.035 mm at 32 C. Growth in relation to temperature was expressed by the equation Y = -0.8474 + 0.0537X, where Y equals daily growth increment and X equals temperature. Larval behavior was normal at 26 to 33.5 C. Critical high and low temperatures for larval survival were 35 C and approximately 20 C. © 1972 by the American Fisheries Society.

The most commonly used measurement of radiation damage to seeds is seedling height, the mean height a lot of seeds attains at some time during exponential growth. If planted immediately post-irradiation, seeds of a dose lot give a normal height distribution, but if stored before planting give very abnormal and even bimodal height distributions. By within-seed comparisons of chromosome abnormality (from roots excised at 24-36 hr) with height (attained by 7-9 days) in irradiated barley seeds, it is shown that damage to height and to chromosomes are closely correlated, even within a treatment in which great heterogeneity occurs. The two effects have equal radiosensitivity, but different shoulders to their dose curves. Seedling height is not depressed until 25-30 per cent of the cells bear chromosomal abnormalities. The heterogeneity observed is not due to a between-seed heterogeneity in dose or in oxygen content, and probably not in moisture. These experiments show that the heterogeneity arises from factors that operate on post-irradiation (indirect) storage damage, but are without effect on during-irradiation damage (direct). © 1969 Pergamon Press Ltd.

Potential environmental impacts on wildlife result from siting and construction (short-term impacts) and habitat removal and fragmentation (long-term impacts) as a consequence of transportation corridor construction. Especially in rural districts, wildlife migration corridors and dispersal orientation are altered or destroyed and wildlife populations and their gene pools are isolated. This significantly weakens the wildlife community. Prudent selection of construction corridors reduces fragmentation impacts by maximizing preserved fragment sizes, and by running parallel to, not through, natural areas. Corridor width determines the degree to which wildlife movement is restricted except that culverts, underpasses, overpasses, and one-way gates, can aid wildlife in cross movements. Minimum underpass dimensions for large wildlife should be no smaller than 14 ft×14 ft and should include natural substratum inverts. Rail corridors have four characteristics that minimize adverse environmental impacts. The railbed is dry, ballast fillters runoff, there is little runoff beyond the toe of slope, and drainage ditches serve to control sheet flow and erosion, sediment movement, and uncontrolled channel flow. Rail corridors usually occupy smaller land areas because they are narrower and are more feasible to elevate so as to allow free movement of wildlife across the corridor. © 1993 Springer-Verlag New York Inc.

The food and habitat niches of two nesting species of hawks Accipiter spp were studied in an extensively forested area of the Eastern Deciduous Forest Biome Nesting habitat was quantitated at 19 Cooper s hawk A cooperu nests and 16 northern goshawk A gentilis nests There was no significant trend for Cooper's hawks to nest in less mature forests than northern goshawks as reported previously for western North America Forest habitats did not differ markedly except that shrub cover was greater at Cooper's hawk nest sites, which were also on flatter terrain and closer to roads, forest openings, and human habitation However, these few differences resulted m reducing habitat‐niche overlap considerably (0 538), as was calculated using principal components analysis Mean prey weight was significantly larger for the northern goshawk which follows its 2 2‐fold body weight advantage over Cooper's hawk Although bird prey was of primary importance to both Accipiter, goshawks took twice the proportion of mammals compared to their smaller congener Food‐niche overlap was lowest by prey species overlap (0 470), followed by prey size class overlap (0 529), and highest by vertical foraging zone overlap (0 816) The Cooper's hawk showed the greatest niche breadth for both food and habitat niches indicating it as more of a generalist Overall, niche complementarity of food and habitat dimensions resulted in niche overdispersion along food and habitat dimensions with a total niche overlap (0 504) that was below the competition threshold These results suggested that competition (past and current) was responsible for segregating niches Copyright © 1992, Wiley Blackwell. All rights reserved

We tested the efficacy of DNA barcodes in identifying mayfly species primarily from the northeastern United States and central Canada. We sequenced a 630-base-pair segment of the mitochondrial gene, cytochrome c oxidase 1 (COI), from 1 individual of each of 80 species to create a reference sequence profile. We used these reference sequences to identify 70 additional specimens representing 32 of the species that were in the profile. DNA barcodes correctly identified 69 of the 70 test specimens. The sole exception was an individual identified morphologically as Maccaffertium modestum that showed deep genetic divergence from other M. modestum specimens. Mean sequence divergence within species was 1%, whereas mean divergence among congeneric species was an order of magnitude greater (18%). We conclude that DNA barcoding can provide a powerful tool for mayfly species identification. © 2005 by The North American Benthological Society.

We observed 16 instances of caching behavior by Northern Saw-whet Owls in southern Connecticut between 30 October and 29 March over a 23-year period 1982 to 2004. Caches consisted of a single prey item in 13 instances and two prey items in three instances. Prey was cached either directly beneath the owl or from 5-28 cm distant, always on the same branch on which the owl was roosting. Observations of cached prey marked in the morning suggested that it was consumed after 14:30 in the afternoon of the same day. Such a delay indicated a true cache rather than delayed feeding.

We collected prey remains from 25 Peregrine Falcon (Falco peregrinus) territories across Arizona from 1977 to 1988 yielding 58 eyrie-years of data. Along with 793 individual birds (107 species and six additional genera), we found seven mammals and nine insects. In addition, two nestling peregrines were consumed. We found a larger dependence upon White-throated Swifts (Aeronautes saxatalis) and birds on migration in northern Arizona, while in southeastern and central Arizona average prey mass was greater and columbiforms formed the largest dietary component. In northern, central, and southeastern Arizona, 74, 66, and 56 avian prey taxa, respectively, were recorded. We used capture-recapture modeling to estimate totals of 111 ± 9.5, 113 ± 10.5, and 86 ± 7.9 (SE) avian taxa taken in these same three areas. These values are counterintuitive inasmuch as the southeast has the richest avifauna. For the entire study area, 156 ± 9.3 avian taxa were estimated to be taken by peregrines.

Larval stages have been associated for all of the known species of Eurylophella in eastern North America except for E. coxalis. The larva of E. coxalis is described herein from a reared series of specimens. Adults are redescribed and eggs are described for the 1st time, as are notes on larval habitat and behavior. Association of E. coxalis completes our knowledge of the life stages of a presumed different species, Dentatella bartoni, which was previously known only from the larval stage. This larva is now determined to be the larval stage of E. coxalis. Further, characters used to diagnose Dentatella danutae have shown that this taxon is not different from what has been called D. bartoni. Thus, Dentatella bartoni (Allen) and D. danutae McCafferty are now placed as subjective junior synonyms of E. coxalis. A conservative criterion requiring that apomorphic characters be discernable in both larval and adult life stages is proposed for recognizing mayfly genera when knowledge of life stages and/or the phylogenetic nature of diagnostic characters is incomplete. Field and laboratory observations of live E. coxalis larvae show this species to be associated with cold, swift, alkaline streams containing coarse inorganic substrates with well-developed periphyton.

Kv3.1, a voltage-dependent potassium channel, has two forms, -a and -b, which differ in expression during development and at the onset of function in the auditory system. To determine whether cochlear nerve input could affect the expression of these two forms, cultures of the developing cochlear nucleus were explanted in the absence of the cochlear nerve at the beginning of cell migration (Hamburger-Hamilton stage 28-30), while neuroblasts continued to migrate onto the culture substrate. After 8, 15, and 22 days in vitro (three survival groups), cultures were immunostained with antibodies recognizing either both forms of Kv3.1 or only the -b form. Only young and newly migrated nerve cells were sampled. In the three survival groups, all nerve cells expressed Kv3.1, among which only 50% or less expressed the -b form. Some of the more differentiated multipolar cells expressed the -b form, but most were labeled with the antibody that recognizes both forms. Thus, in the absence of peripheral input, both forms of Kv3.1 appear at stages very early in development, although not all cells necessarily coexpress both forms. These results agree with other observations in the chick embryo in situ. They are consistent with previous work implicating Kv3.1 in cell migration during early development.

Hemigrapsus sanguineus Asian Shore Crab is an introduced but now common crab found intertidally along the Connecticut coastline. Little is known of its subtidal occurrence. This species was found to be seasonally abundant subtidally, at depths varying from 1.33.9 m, during a 2-year study conducted within a commercial marina in Clinton Harbor, CT. Hemigrapsus sanguineus was trapped at three subtidal locations, with highest concentrations observed during the winter. A total of 2020 crabs were caught: 1255 males, 741 females, and 24 crabs that were 9 mm or smaller and sexually indistinguishable. Large males with carapace widths between 4548 mm were captured at all three locations. These sizes are among the largest reported for this species. This work documents year-round use of subtidal habitat by Asian Shore Crab in Long Island Sound.