A proposed mechanism for enhanced water-conservation in egg clutches of the Mexican Kingsnake, Lampropeltis mexicana (Serpentes: Colubridae)

A postura de ovos em um substrato úmido minimiza o estresse hídrico de ovos de répteis com casca coriácea, pois permite que absorvam água através da casca permeável. Esse ganho de água contribui para a redução da perda de água em ovos agregados. Demostramos aqui essa característica de conservação de água em ovos da serpente Lampropeltis mexicana em um experimento de balanco hídrico investigando tanto desovas naturais como ovos arranjados experimentalmente em grupos. As taxas de perda de água dos ovos continuam a diminuir à medida que mais ovos são adicionados ao agregado, com um limiar de aproximadamente 15 ovos. Não há redução adicional da taxa de perda de água em um agregado de 20 ovos, número maior que o tamanho típico máximo da desova natural dessa espécie. Correntes de ar seco dirigidas sobre a desova provocam o desaparecimento dessa característica de conservação de água, mas esta reaparece quando o ar está imóvel (desligando-se a corrente de ar). Essa é a primeira vez que um aumento na pressão de vapor de água em um agregado de ovos é demonstrado experimentalmente; os resultados sugerem que a postura de ovos agregados pode beneficiar o desenvolvimento por meio da conservação de umidade.Laying eggs on a wet substrate minimizes water stress for flexible-shelled reptile eggs because they absorb water through the permeable shell. This water gain contributes to reduced water-loss in aggregated eggs. This water-conserving feature is demonstrated in eggs of Lampropeltis mexicana in a water-balance experiment investigating both naturally laid clutches and eggs in arranged clusters. Water-loss rates of eggs decrease as more eggs are added to the aggregation, with a threshold at approximately 15 eggs. There is no further reduction in water-loss rate for eggs in an aggregation of 20, which exceeds the typical maximum for natural clutch size in this species. Blowing dry air over the egg clutch causes this water-conserving feature to disappear, but it re-appears when the air is still (air current turned off). This is the first time that an increase in water-vapor pressure in an aggregation of eggs has been demonstrated experimentally; the results suggest that laying aggregations of eggs may benefit development through moisture conservation

Expanding Distribution into the Midwest by the Lone Star Tick is Facilitated by Recognizing Excreta of Previously Established Ticks

The southeastern lone star tick, Amblyomma americanum, has recently appeared in our field sweeps. This new tick in our area brings the potential for diseases, such as ehrlichiosis, tularemia, and Southern rash illness borreliosis. Favorable habitats are indicated by excreta of ticks that are already established, with the excreta acting as an assembly pheromone that retains ticks in areas with proper temperature, moisture, and suitable hosts. Our hypothesis is that excreta from different tick species may function as an assembly pheromone for lone star ticks, which may have contributed toward lone star ticks establishing here. Clustering responses by lone star ticks on excreta of ticks from different tick species was tested using six-sector Petri dish attraction bioassays with an added relative humidity component. Dry 33% RH conditions elicited greater clustering (higher speed, more ticks involved) than under humid 93% RH, mostly by female adults and nymphs and only a few larvae. Greatest response was to excreta of black-legged tick Ixodes scapularis. Other excreta that was attractive and resulted in clustering, but less intense, was Gulf Coast tick A. maculatum, American dog tick Dermacentor variabilis, and brown dog tick Rhipicephalus sanguineus. The conclusion is that lone star ticks can recognize assembly pheromone of other ticks, migration probably occurs by adults during dry weather, and arrival of the Lyme disease vector I. scapularis seems likely

Feeding on Different Types of Pollen Enhances Suitability for Release of the Red Mite as a Biological Control Agent Against a Variety of Plant Pests

The red mite Balaustium murorum, readily consumes aphids, scale insects, white flies, spider mites, and their eggs, making this mite useful in classical biological control programs. This mite is also a pollen-feeder, switching from pollen to prey as prey becomes available through the spring. This study tests the hypothesis that specific plants may dictate where red mites establish, which may be important where these mites could be used for plant pest control. Accordingly, mites in six-sector Petri plate attraction bioassays with pollen that was collected from different plants and then staining the pollen with Evans blue as a tracer was used to examine feeding rates. All mite stages (larvae, deutonymphs, and females) ingested pollen grains whole, as evidenced by blue coloration in the gut, and from a variety of sources: tulip, pear, maple, crabapple, viburnum and narcissus cultivars. Larvae were the most aggressive feeders, based on speed of clearance of piles of pollen, amount consumed, and number of mites feeding on pollen at any one time; activity by deutonymphs and females was not as vigorous. There was no positive attraction to fed mites, thus suggesting that mites encounter pollen at random and not by an aggregation pheromone released by others. The conclusion of this experiment is that many pollen-producing plants can contribute toward setting up these mites in a new geographic application

Control Measures For Reducing Amount of Allergenic Molds Carried by Seed Beetles in a Science Classroom Setting

Manageable body size, inability to fly, simple life history, hardiness, and ease of handling have quickly made the seed beetle, Callosobruchus maculatus, a staple for hands-on projects and in biology lessons taught nationwide from elementary school classrooms to undergraduate biology laboratories. Working with insects and their debris routinely results in mold-related allergies, as is well-known to people that work with insects (essentially what the students would be doing), with symptoms ranging from skin irritation to watery eyes, sneezing, difficulty breathing, and in severe cases anaphylaxis. Based on the premise that the beetle colony may be a rich source of allergenic molds, our goal was to culture fungi for identification and enumeration from live beetles, dead beetles, and their storage containers of mung beans and cowpeas. Beetle colonies from elementary schools, university insectary, and commercial supplier were sampled. Many fungi representing nine genera were recovered, including Aspergillus, mainly A. niger, Alternaria, Rhizopus and Mucor, all of which are medically significant and found in all sites (similar Simpson index) sampled. The largest difference was observed in colonies where beetles fed and hatched from mung beans than cowpeas, noting a 2/3 reduction in total molds when beetles were raised on mung beans. We also noted nearly double the mold level in older cultures than newer ones. Our conclusion is that disposing of old, used seeds and rearing on mung beans are two steps that can be taken to reduce allergenic molds and make using these beetles more safe for students

Cave Crickets Have No Evidence of Carrying the Fungus That Causes White-Nose Syndrome in Bats from Small Caves in the Cumberland Plateau

We report absence of Pseudogymnoascus destructans, reputed fungal agent of white-nose syndrome in bats, in surveys of fungal components and percentage composition of cave crickets Hadenoecus (at least in the caves we sampled). This survey was done to test the hypothesis that cave crickets may carry P. destructans based on observations that P. destructans has recently been found to be a regular cave inhabitant in soil in caves with or without bats, and crickets and bats are in close proximity by occupying similar sites on cave ceilings and bells. This survey included crickets that differed by the extent that they travel outside for foraging, to examine how their movements and ability to function outside impact the fungi they carry. Incubation conditions for fungus culturing were 12oC and darkness, consistent with cave conditions and psychrophilic nature of P. destructans, on three different agar media. Ability to function was inferred by determining water balance characteristics. H. cumberlandicus (Kentucky) featured a slow water loss rate, low cuticular permeability, and a large fungus load; thus, they can function outside the cave longer and are exposed to more fungal spores in their foraging habitat. Higher water loss rates, larger cuticular permeabilities, and lower fungal loads characterized H. opilionoides (Tennessee) and H. jonesi (Alabama) that are more cave-adapted, seldom venturing out, thereby coating themselves with less fungi, because they are more prone to desiccation. There was little difference in Simpson index of fungal components, with all crickets having similar fungal composition: dominated by probiotic Aspergillus and Penicillium, and smaller amounts of Cladosporium, Fusarium, Mucor and Rhizopus. We conclude that the role of cricket fungi, with large proportion of probiotic fungi, is to protect them from potential pathogens and there is extra protection for crickets that venture outside more frequently

Chalkbrood Fungal Infection as a Signal of Health-Related Problems, Poor Nutrition, and Distress in Honey Bee Colonies

Larvae of the honey bee (Apis mellifera) can get infected and killed by the fungus Ascosphaera apis, which consumes the larva from inside out, then dries, creating a mummy, so-called chalkbrood. A warm or chilling shock to the brood accentuates the disease. Recently, beekeepers have reported increased chalkbrood in their colonies. Examining record books of these colonies indicate treatment with high fructose corn syrup (HFCS), antibiotics, and miticides. To examine the link that may exist between chalkbrood and treatments applied to colonies, growth rate of A. apis was determined by fungus culture under strong chalkbrood-inducing temperatures on agar supplemented with crushed bee larvae as a mock-infection. Implementing chilling, or warming cues caused no particular growth rate enhancement of A. apis, while miticides had a negative effect on growth, sometimes killing the fungus. HFCS and antibiotics, alone and mixed, did not positively or negatively alter growth of A. apis. We conclude that chalkbrood is not a pathogenic consequence of HFCS, antibiotics, miticides, or temperature shocks, but rather is related to the bee where these treatments signal other health problems that make the bee more prone to infection

A proposed mechanism for enhanced water-conservation in egg clutches of the Mexican Kingsnake, Lampropeltis mexicana (Serpentes: Colubridae)

Laying eggs on a wet substrate minimizes water stress for flexible-shelled reptile eggs because they absorb water through the permeable shell. This water gain contributes to reduced water-loss in aggregated eggs. This water-conserving feature is demonstrated in eggs of Lampropeltis mexicana in a water-balance experiment investigating both naturally laid clutches and eggs in arranged clusters. Water-loss rates of eggs decrease as more eggs are added to the aggregation, with a threshold at approximately 15 eggs. There is no further reduction in water-loss rate for eggs in an aggregation of 20, which exceeds the typical maximum for natural clutch size in this species. Blowing dry air over the egg clutch causes this waterconserving feature to disappear, but it re-appears when the air is still (air current turned off). This is the first time that an increase in water-vapor pressure in an aggregation of eggs has been demonstrated experimentally; the results suggest that laying aggregations of eggs may benefit development through moisture conservation

In vitro evaluation of sugar syrups, antibiotics, and miticides on growth of honey bee pathogen, Ascosphaera apis: Emphasis for chalkbrood prevention is on keeping bees healthy

International audienceTo examine the link between chalkbrood and treatments applied to honey bee (Apis mellifera) colonies, growth of Ascosphaera apis was determined under chalkbrood-inducing conditions on agar containing crushed bee larvae as a mock infection. Treatments were tested at concentrations in the field, representative of beekeeping practice (at least in the USA). A chilling or warming stress known to heighten chalkbrood caused no growth enhancement of A. apis. Miticides had a negative effect; formic acid killed A. apis and oxalic acid reduced growth by 70 %. High-fructose corn syrups and sucrose syrup undiluted, a 50:50 mixture, alone, and with antibiotics did not alter growth of A. apis. We conclude that chalkbrood does not develop from a temperature- or treatment-induced activation of A. apis. Sugar syrups, miticides, and antibiotics point out other health problems that make bees prone to infection by A. apis. Thus, chalkbrood opportunistically infects bees under other forms of stress

Enhancing glucose flux into sweat by increasing paracellular permeability of the sweat gland

<div><p>Non-invasive wearable biosensors provide real-time, continuous, and actionable health information. However, difficulties detecting diluted biomarkers in excreted biofluids limit practical applications. Most biomarkers of interest are transported paracellularly into excreted biofluids from biomarker-rich blood and interstitial fluid during normal modulation of cellular tight junctions. Calcium chelators are reversible tight junction modulators that have been shown to increase absorption across the intestinal epithelium. However, calcium chelators have not yet been shown to improve the extraction of biomarkers. Here we show that for glucose, a paracellularly transported biomarker, the flux into sweat can be increased by >10x using citrate, a calcium chelator, in combination with electroosmosis. Our results demonstrate a method of increasing glucose flux through the sweat gland epithelium, thereby increasing the concentration in sweat. Future work should examine if this method enhances flux for other paracellularly transported biomarkers to make it possible to detect more biomarkers with currently available biosensors.</p></div