Oviposition,larval survival and leaf damage by the willow leaf blotch miner,Micrurapteryx salicifoliella,in relation to leaf trichomes across 10 Salix species

1. Foliar trichomes clearly reduce chewing damage and efficiency of movement by some insect herbivores, but the effect of trichomes on insect oviposition is less well characterised. Trichomes are likely to have particularly strong, negative effects on species that require secure attachment of the egg to the leaf epidermis for successful transition to the feeding stage – a group that includes many leaf mining insects. 2. One such species, Micrurapteryx salicifoliella, must initially enter leaf cells directly from an egg adhered to the cuticle, but later instars can move between leaves and initiate new mines from the leaf exterior. 3. Natural patterns of occurrence by M. salicifoliella were quantified on 10 sympatric Salix species varying in trichome expression to test whether trichomes were associated with reduced oviposition, larval survival and leaf damage. 4. Mean egg density and leaf mining damage were negatively related to mean trichome density across Salix species. Survival of M. salicifoliella from egg to pupa was positively related to trichome density, suggesting that initiation of new mines by late‐instar larvae was not adversely affected by trichomes. There was no evidence that trichomes benefited leaf miner larvae indirectly by decreasing density‐dependent mortality; rather, the positive relationship between trichome density and larval survival may reflect less effective chemical defence by Salix species expressing high trichome density. 5. The results suggest that foliar trichomes serve as an effective defence against M. salicifoliella by deterring oviposition, but do not reduce the survivorship of those individuals that successfully transition from egg to larva.     

Puncture-Resistance of Gloves for Handling Bats

ABSTRACT We quantified protection given by a variety of gloves against bat bites by using steel indenters to simulate teeth and measuring forces needed to puncture the gloves. Level of protection given by gloves was compared to expected bite forces and tooth sharpness of bats. Cotton, plastic-coated synthetic fabric, and proprietary materials advertised as puncture- and cut-resistant were easy to penetrate compared to leather gloves. Split leather gives the highest level of protection, but with reduced dexterity. These are best for handling larger bats (>40 g) or if higher safety is preferred. Deerskin gives reasonable protection without much loss in dexterity for handling bats <40 g.     

Population biology of swift (Apus apus) ectoparasites in relation to host reproductive success

Abstract.

• 1 We censused ectoparasite populations of adult and nestling swifts over the course of the host's breeding season. Nearly all of the birds were infested with chewing lice and two-thirds of the nests were infested with louse flies. Feather mites were observed but not quantified.
• 2 Lice and louse flies both showed aggregated distributions among hosts. Louse eggs, hatched lice and adult louse flies had negative binomial distributions, whereas the aggregated distribution of louse fly pupae was not adequately described by negative binomial or Poisson models.
• 3 Transmission of lice from parents to offspring was documented. A comparison of the age structure of lice on parents and offspring indicated that most transmission was by nymphal lice.
• 4 Host reproductive success and survival appeared to be independent of the number of lice or louse flies. Neither parasite correlated with the number, body mass, or date of fledging of young birds, nor with the overwinter survival of adults. We caution, however, that experimental manipulations of parasite load are required for a definitive test of the impact of ectoparasites on evolutionary fitness components.

     

Gram-Chromotrope: a New Technique that Enhances Detection of Microsporidial Spores in Clinical Samples

We have developed a new staining procedure that combines the traditional Gram staining for bacteria and the Weber's chromotrope staining method, the standard technique for the detection of microsporidia spores in clinical Specimens. This “Gram-chromotrope” staining technique enhances the staining characteristics of microsporidia spores and facilitates the easy detection and differentiation of spores from other microorganisms that are found in clinical specimens, especially stool samples. This new technique is fast, reliable, and simple to perform, and can be easily adapted for use in clinical laboratories.     

Changes in the Architecture of Cancellous Bone in the Femora of Developing Mice as a Result of Short Duration Hypergravity

SYNOPSIS. Mice were used as a model system to demonstrate theeffects of increased loading on the trabecular bone in the developingproximal femur. A two-dimensional free body diagram revealedthat because the femur is normally held in a horizontal positionduring support, functional loading resulted in a net posteriorbending moment and a muscle generated axial compressive loadthat was 7.7 times the normal support weight for that limb.Experimental treatment consisted of four times normal gravityfor 10 min, six times per day for 30 days in addition to unrestrainednormal exercise. Unrestrained normal exercise served as thecontrol. An animal whose foot was amputated by his mother shortlyafter birth was used as a less than normal load example forcomparison with the hypergravity and control groups. All groupswere treated for 30 days. Two areas of trabecular bone wereexamined: a proximal central webbing area that may be underpredominantly tensile loading much of the time, and a more distalarea near the third trochanter that presumably experiences bendingstresses when the animal is exposed to normal activity or hypergravity.Results indicate that: 1) The central webbing area appears tohave a similar mass of bone regardless of loading conditions;however, with increased loading the trabeculae become orientedin directions that approximate directions of presumed principaltensile stresses. 2) There is no genetically predetermined amountof bony tissue in the third trochanter area; when the limb isrelatively unloaded no trabeculae are present, as the loadingincreases trabecular bone is formed. In the hypergravity group,trabeculae in the area of the third trochanter increased inlength and complexity and became more centrally positioned inthe lumen of the femur, a position that presumably would allowthe femur to better resist bending moments. These results demonstratethat short duration, high intensity functional loading can stimulategrowth of trabecular bone, and further, specific types of functionalloading can be correlated with specific architectural changes.     

Laboratory observations on the effect of humidity on the persistence of infectivity of conidia of the aphid pathogen Erynia neoaphidis

Conidia of the aphid pathogen Erynia neoaphidis on detached bean leaves and glass coverslips maintained at 20°C and at humidities from 40 to 100% r.h. lost their infectivity for pea aphids at a rate dependent on the humidity. Infectivity declined most rapidly in inocula kept on leaves at 70% r.h. and persisted longest in those at 40 and 50% r. h. That of inocula on coverslips declined most rapidly at 77% r.h. and persisted longest in those kept at 40% r.h. Even after 21 days a little infectivity was retained by conidia stored at 50% r.h. on leaves and 40% r.h. on coverslips.     

Comparison of the Surface Proteins and Glycoproteins On Erythrocytes of Calves Before and During Infection With Babesia Bovis

The surface proteins and glycoproteins on red cells from normal and Babesia bovis-infected calf blood have been compared. Several radiolabeling probes were used to label specifically external membrane molecules which were then separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and identified by autoradiography or fluorography. No differences were observed among the Coomassie Blue-stained membrane proteins of erythrocytes from individual uninfected calves. Comparison of red cells from these animals also indicated no qualitative differences in the surface proteins with accessible tyrosyl residues labeled by lactoperoxidase-catalyzed radioiodnation, although some quantitative variation in the uptake of radioactivity into particular proteins was observed. the major radioiodinated bands on normal bovine erythrocytes had Mr of 165, 130, 90, and 45 kiloDaltons. However, labeling of surface glycoproteins by the periodate/[³H]NaBH₄ and galactose oxidase (± neuraminidase)/[³H]NaBH₄ methods showed significant differences in the surface proteins of red cells from individual uninfected calves. of 14 animals tested, 5 had major labeled glycoproteins of unique Mr. No changes were observed in radioiodinated surface proteins of total red cell samples from infected calves with 0.5-6% parasitemia. Radioiodination of concentrated infected red cells from the same samples (concentrated by selective hypotonic lysis of uninfected erythrocytes in KC1) resulted in the labeling of 3 new surface proteins, with Mr of 118, 115, and 60 kiloDaltons. the same new ¹²⁵I-labeled bands were identified on infected cells from 3 avirulent strains of B. bovis used in vaccine production. Furthermore, in concentrated infected cells there was very poor radiolabeling of major bands strongly labeled on uninfected cells (Mr 165, 130, and 90 kiloDaltons), suggesting parasite-induced loss of these proteins. Although there were some differences in ³H-labeled surface glycoproteins of red cells from normal and. B. bovis -infected blood, they were restricted to minor labeled bands and were not seen consistently. the labeled surface glycoproteins of concentrated infected cells were very similar to those of the uninfected red blood cells from infected blood.