Capsicum oleoresin: development of an in-soil repellent for pocket gophers

A pre- and post-monitoring study was conducted of the potential use of capsicum oleoresin as an in-soil repellent for northern pocket gophers (Thomomys talpoides). Pocket gophers were captured in irrigated alfalfa (Medicago sativa L), affixed with radio transmitters, and monitored daily for location. Six plots (4.87 × 4.87m) each were randomly assigned to capsicum oleoresin and soybean oil treatments; these were set up based upon the centers of initial core areas of gophers. Mean (±SD) volumes of capsicum oleoresin and water and soybean oil and water mixtures (10 + 90 by volume) dispensed onto plots equaled 178.5 (±4.7) and 175.7 (±14.0) liters, respectively. Movements (m) of the radio-transmitted gophers from plot centers were computed for four daily readings (i.e., 0801–1000, 1101–1300, 1501–1700 and 1801–2000 h). Spectrophotometric analysis of soil samples from capsicum oleoresin plots validated the presence of capsicum on plots and the absence of capsicum on placebo- and off-plot locations. Analysis of variance for movement distances of gophers yielded a Date main effect [F(11, 103) = 2.08, P ≤ 0.03] and a Date × Reading (time) interaction [F(32, 299) = 3.21, P ≤ 0.01]. Results showed that gophers were located farther from plot centers for the 0801–1000 and 1501–1700 h telemetry readings for ≤3days postchemical application—a probable ‘disturbance’ effect rather than a chemical-induced avoidance. In a prior laboratory study, capsicum oleoresin and soil treatments of 1.5% w/w capsicum caused nearly a 50% decrease in soil contact time by gophers relative to placebo-exposed control animals. This implies that procedural variables warrant revision before abandoning this approach. The potential for soil insertion of repellents as a technique for expelling pocket gophers from territories and some methodological changes for future research of the technique are discussed

The emerging structure of the Extended Evolutionary Synthesis: where does Evo-Devo fit in?

The Extended Evolutionary Synthesis (EES) debate is gaining ground in contemporary evolutionary biology. In parallel, a number of philosophical standpoints have emerged in an attempt to clarify what exactly is represented by the EES. For Massimo Pigliucci, we are in the wake of the newest instantiation of a persisting Kuhnian paradigm; in contrast, Telmo Pievani has contended that the transition to an EES could be best represented as a progressive reformation of a prior Lakatosian scientific research program, with the extension of its Neo-Darwinian core and the addition of a brand-new protective belt of assumptions and auxiliary hypotheses. Here, we argue that those philosophical vantage points are not the only ways to interpret what current proposals to ‘extend’ the Modern Synthesis-derived ‘standard evolutionary theory’ (SET) entail in terms of theoretical change in evolutionary biology. We specifically propose the image of the emergent EES as a vast network of models and interweaved representations that, instantiated in diverse practices, are connected and related in multiple ways. Under that assumption, the EES could be articulated around a paraconsistent network of evolutionary theories (including some elements of the SET), as well as models, practices and representation systems of contemporary evolutionary biology, with edges and nodes that change their position and centrality as a consequence of the co-construction and stabilization of facts and historical discussions revolving around the epistemic goals of this area of the life sciences. We then critically examine the purported structure of the EES—published by Laland and collaborators in 2015—in light of our own network-based proposal. Finally, we consider which epistemic units of Evo-Devo are present or still missing from the EES, in preparation for further analyses of the topic of explanatory integration in this conceptual framework

Gut Flora Metabolism of Phosphatidylcholine Promotes Cardiovascular Disease

Metabolomics studies hold promise for the discovery of pathways linked to disease processes. Cardiovascular disease (CVD) represents the leading cause of death and morbidity worldwide. Here we used a metabolomics approach to generate unbiased small-molecule metabolic profiles in plasma that predict risk for CVD. Three metabolites of the dietary lipid phosphatidylcholine—choline, trimethylamine N-oxide (TMAO) and betaine—were identified and then shown to predict risk for CVD in an independent large clinical cohort. Dietary supplementation of mice with choline, TMAO or betaine promoted upregulation of multiple macrophage scavenger receptors linked to atherosclerosis, and supplementation with choline or TMAO promoted atherosclerosis. Studies using germ-free mice confirmed a critical role for dietary choline and gut flora in TMAO production, augmented macrophage cholesterol accumulation and foam cell formation. Suppression of intestinal microflora in atherosclerosis-prone mice inhibited dietary-choline-enhanced atherosclerosis. Genetic variations controlling expression of flavin monooxygenases, an enzymatic source of TMAO, segregated with atherosclerosis in hyperlipidaemic mice. Discovery of a relationship between gut-flora-dependent metabolism of dietary phosphatidylcholine and CVD pathogenesis provides opportunities for the development of new diagnostic tests and therapeutic approaches for atherosclerotic heart disease

A REVIEW OF CHEMICAL AND PARTICLE MARKING AGENTS USED FOR STUDYING VERTEBRATE PESTS

A wide variety of chemicals including dyes, stains, inks, drugs, fluorescent and non-fluorescent particles, and radioisotopes have been used as markers to identify free-ranging mammals and birds. Markers are useful for studying: (1) home ranges, migration patterns, and population dynamics; (2) bait acceptance, palatability, and exposure of target animals via different baiting techniques for delivering toxicants, chemosterilants, or vaccines; and (3) exposure of non-target animals to control techniques. Five general classes of markers with specific marking capabilities are available for use: (1) dyes, stains, and inks that may be either fluorescent or non-fluorescent which stain the gastro-intestinal tract and its contents, urine, fecal droppings, or hair; (2) inert particles, either fluorescent or non-fluorescent, that can be detected in the gastro-intestinal tract and feces, and can be applied with an adhesive spray to birds\u27 feathers; (3) tetracyclines that can be detected as a yellow fluorescence in bones and teeth; (4) blood markers that can be detected in the plasma or sera (e.g., iophenoxic acid or mirex); and (5) radioisotopes that have various patterns of tissue distribution depending upon the isotope used

REPELLENTS TO REDUCE CABLE GNAWING BY WILD NORWAY RATS

Rodents gnaw communications and power cables, resulting in service interruptions, fires, and other safety concerns. Commensal rodents such as the Norway rat (Rattus norvegicus) have been implicated in many of these situations. Two chemical repellents (capsicum oleoresin+apsaicin and denatonium benzoate) at 2.0% mass/mass concentrations in a polybutene carrier (Indopol-controlw) ere evaluated for repellent efficacy compared to a plastic mesh physical barrier material (Vexa*) and the polybutene carrier (placebo) alone using groups of individually caged wild Norway rats. The materials were applied to short lengths of communications cable (RG-8U) with the repellents enclosed in electrical shrink tubing around the samples and the plastic mesh attached to the samples for 7 days of continuous rat exposure. Measures of damage taken after rat exposure included mass of cable material damaged, volume loss to gnawing, depth of gnaw penetration, width of gnawing, and a qualitative index of damage based upon visual appearance. Using a stepwise discriminant analysis, we found less damage (P \u3c 0.05) using the volume loss measure (cc) for the capsaicin and for the denatonium groups than for the polybutane-carrier (placebo) group. Other measures of gnawing damage did not improve statistical comparisons of the repellents. For all 5 measures of damage, there was a consistent rank order pattern among the means with capsaicin \u3c denatonium \u3c Vexar \u3c Indopol-control

Repellents to Reduce Cable Gnawing by Northern Pocket Gophers

There is a continuing need to develop improved repellent formulations to protect buried cable installations from damage by problem wildlife. We evaluated 2.0% mass/mass levels of capsaicin and denatonium benzoate in a polybutene carrier material (Indopol®) and an aboveground, rodent-deer plastic mesh barrier (Vexar®) for reducing gnawing by northern pocket gophers (Thomomys talpoides) on communications cable (RG-8U). When treatments were applied as surface coatings, neither capsaicin nor denatonium samples were lower (P \u3e 0.05) in measnres of cable damage compared to control (Indopol® alone) or samples treated with Vexar® plastic mesh. When the test was repeated with a new group of 24 gophers (n = 6/group in each of 4 groups) but with the 2.0% capsaicin, 2.0% denatoniuin benzoate, and Indopol® enclosed with electrical shrink tubing, there was less damage for the capsaicin samples (P \u3c 0.05) on mass, depth of cut, width, and volume of cable chewed when compared to samples treated with the Vexar® and Indopol®. Denatonium benzoate treatment also prodnced repellent effects (P \u3c 0.05) on the width measure when compared to Vexar® samples. In addition, the denatonium benzoate samples were damaged less than Indopol® samples, although not significantly, as measured by mass loss and depth of gnawing. Therefore, we concluded that although capsaicin and denatoneum benzoate appeared to be completely ineffective when applied as a surface coating to cable, the same agents became effective cable gnawing repellents when encased in electrical shrink tubing. This encasing procedure demonstrated quite clearly that the means for applying the repellent agent are an all-important aspect of developing effective products to control gnawing damage by northern pocket gophers

BEHAVIORAL RESPONSE OF QUELEA TO METHIOCARB (MCSUROL)*

The small African weaver finch commonly known as Quelea (Quelea quelea) has been reported (Crook and Ward, 1968) to be one of the most numerous and destructive birds in the world and is found extensively throughout Africa (DeGrazio, 1974). Quelea have been associated with damage to many agricultural crops including millet, grain sorghum, rice, and wheat. Because current population control programs in Africa have not reduced damage except in a few local areas (Crook and Ward, 1968), more effective damage control methods need to be Inves- tigated. One promising method, protection of the agricultural crop with a chemical repellent, methiocarb, has been demonstrated to be highly effective (Guarino, 1972). Small scale efficacy demonstrations in Tanzania (DeGrazio, 1974) with three pounds of methiocarb per acre to protect maturing rice and wheat have reduced Quelea damage by about 90 percent. Methiocarb is thought to produce a post-ingestional effect in the affected birds (Guarino, 1972). Rogers (1974) has presented some evidence that methiocarb, unlike a highly bitter-tasting compound (sucrose octaacetate), affects feeding activity of Red-winged Blackbirds (Ageliaus phoenlceus), but some time delay is required for affectation and subsequent feeding aversion. The development of the repellent (or aversion) response for methiocarb was similar to the aversive response shown to lithium chloride (LiCl), a salt that has been traditionally used to study conditioned aversion in rats (Nachman, 1963). This aversion effect is then thought to become quickly associated with the taste of methiocarb or treated food material (Crase and DeHaven, 1976). Schafer, Brunton, and Lockyer (1977) observed that most of the seven bird species they tested [Robins (Turdus migratorius), Brown-headed Cowbirds (Molothrus ater), White-crowned Sparrows (zonotrlchia leucophrys). House Sparrows (Passer domesticus), Starlings (sturnus vulgaris), Grackles (Quiscalus qaiscula), and Red-winged Blackbirds] displayed more food aversion and longer-lasting conditioning to methiocarb when compared with thiram (TMTD), a taste repellent. Both repellent materials were placed on food particles at levels slightly lower than the R-50 for Red-winged Blackbirds (Schafer and Brunton, 1971). To more effectively predict field application rates for protecting cereal grains from Quelea damage in Africa, we felt it necessary to compare the sensitivity of Quelea to methiocarb with sensitivities reported for other bird species (Schafer and Brunton, 1971). In addition, we wanted to determine the relative importance of taste versus visual feeding cues that could become associated with methiocarb exposure in Quelea. Knowledge gained from these studies could lead to an improved application method that would enhance the long-term repellent action of methiocarb with low level methiocarb treatments in conjunction with other stimuli. Aversive cues could also be used to alter food-searching behavior (Crase and DeHaven, 1976) so that Quelea repelled from agricultural crops would more quickly seek alternate natural foods such as grass or weed seeds and Insects

Impacts of small mammals and birds on low-tillage, dryland crops

During 2000–2001, small mammals, birds, and potential corn/soybean damage were studied at a low-tillage, non-irrigated agricultural research site in the Colorado Piedmont. A small mammal surveyinvolved four trapping sessions and 18, 12-live-trap grids each. Within years, two grids each were placed at random, fixed locations in experimental corn, fallow, millet, pea, soybean, sunflower, and wheat plots at the site; two off-plot grids each were set at random, fixed locations \u3c100m from the north and south edge of these plots. In 2001, periodic bird observations were conducted, and damage to corn and soybean plants was assessed. Capture rates were low during all trap sessions (range 0.1%–3.3%, Χ̅ = 2:2%). Sixty-three small mammals were captured and 39 were recaptured. Captures included deer mouse (Peromyscus maniculatus), northern grasshopper mouse (Onychomys leucogaster), thirteen-lined ground squirrel (Spermophilus tridecemlineatus), and western harvest mouse (Reithrodontomys megalotis). Deer mice accounted for 56 of the initial captures (88.9%). In-crop captures (n =15) and recaptures (n = 16) were most frequent in wheat plots. Bird counts were low and included horned lark (Eremophila alpestris), killdeer plover (Charadrius vociferus), lark bunting (Calamospiza melanocorys), mountain plover (Charadrius montanus), mourning dove (Zenaida macroura), and western meadowlark (Sturnella neglecta). No direct seed removal, sprout removal, or plant clipping bysmall mammals or birds was observed, but some clipping of soybean plants was attributed to deer (Odocoileus virginianus and O. hemionus) and jack rabbits (Lepus townsendii or L. californicus). Plant debris accumulation is viewed as a keyfactor determining small mammal abundance and potential damage in low-till agriculture