Modifier gene study of meconium ileus in cystic fibrosis: statistical considerations and gene mapping results

Cystic fibrosis (CF) is a monogenic disease due to mutations in the CFTR gene. Yet, variability in CF disease presentation is presumed to be affected by modifier genes, such as those recently demonstrated for the pulmonary aspect. Here, we conduct a modifier gene study for meconium ileus (MI), an intestinal obstruction that occurs in 16–20% of CF newborns, providing linkage and association results from large family and case–control samples. Linkage analysis of modifier traits is different than linkage analysis of primary traits on which a sample was ascertained. Here, we articulate a source of confounding unique to modifier gene studies and provide an example of how one might overcome the confounding in the context of linkage studies. Our linkage analysis provided evidence of a MI locus on chromosome 12p13.3, which was segregating in up to 80% of MI families with at least one affected offspring (HLOD = 2.9). Fine mapping of the 12p13.3 region in a large case–control sample of pancreatic insufficient Canadian CF patients with and without MI pointed to the involvement of ADIPOR2 in MI (p = 0.002). This marker was substantially out of Hardy–Weinberg equilibrium in the cases only, and provided evidence of a cohort effect. The association with rs9300298 in the ADIPOR2 gene at the 12p13.3 locus was replicated in an independent sample of CF families. A protective locus, using the phenotype of no-MI, mapped to 4q13.3 (HLOD = 3.19), with substantial heterogeneity. A candidate gene in the region, SLC4A4, provided preliminary evidence of association (p = 0.002), warranting further follow-up studies. Our linkage approach was used to direct our fine-mapping studies, which uncovered two potential modifier genes worthy of follow-up.     

An Investigation of Factors Influencing Bear Spray Performance

Several studies have documented the effectiveness of bear spray in protecting users from aggressive bears. Bear spray failures, however, have also been reported along with speculation regarding the influences of temperature, wind, repeated canister use, and canister age on spray efficacy. We designed lab and field experiments to document the influence that temperature, wind, repeated discharges from the same canister, and canister age have on bear spray performance. To determine the influence of temperature on spray performance, we recorded canister head pressures at temperatures ranging from −23°C to 25°C and found a strong, positive linear relationship. Even at the lowest temperature tested (−23°C), bear spray had a range >4 m, though the plume was narrow and the spray was not well aerosolized. As canister temperature increased, head pressure, plume distance, and dispersion increased. We used computational fluid dynamics modeling and simulated the effect that headwinds, crosswinds, and tailwinds of varying speeds had on spray performance. Even under high headwind and crosswind scenarios (>10 m/sec), sprays reached targets that were approximately 2 m directly in front of the user. Crosswinds affected spray plume distance similar to headwinds, but the effect was not as pronounced. Tailwinds improved spray performance with respect to speed and distance. By weighing unused canisters ≤18 years old, brands tested lost weight ranging from 0.65 g/year to 1.92 g/year, presumably because of propellant that escaped canister seals. We also documented that bear spray head pressure declines in a logarithmic, not linear, fashion; over half of a new (7-sec spray time) canister's pressure was lost in the first 1 second of spray. We recommend not test-firing cans, keeping cans warm when in the cold, and retiring them when ≥4 years of age. Our results provide no compelling reason to not carry bear spray in all areas where bears occur, even if it is windy or cold. © 2020 The Wildlife Society.     

Mites (Acari,Mesostigmata) in boreal Scots pine forest floors: effect of distance to stumps

Coarse woody debris (CWD) is a basic component of forest ecosystems and it plays a crucial role in species-poor boreal forests. Generally, previous studies have focused on differences between the forest floor and decaying logs of various tree species. The impact of distance to CWD has been investigated mainly for forest-floor snails and some groups of macrofauna, but not yet for mesostigmatid mites communities. We hypothesized that the effect of CWD decreases with increasing distance from CWD. To test this hypothesis we conducted a study in relatively species-poor Finnish boreal forest (at ca. 100 km northwest of Helsinki). In total, 81 samples were collected in 2007 from nine Scots pine (Pinus sylvestris) stumps, three microhabitats (CWD, soil/litter at 0.5 m from a stump and soil/litter at 1.5 m from a stump) and in three main directions (9 stumps × 3 microhabitats × 3 directions). Overall, 1965 mesostigmatid mites were collected representing 24 species. The mean number of mite species collected was significantly different between decaying stumps and forest litter; however, there was no significant difference between the litter samples at 0.5 and 1.5 m distance. The evenness index was significantly lower for samples collected from stumps than for litter in close (0.5 m) or far (1.5 m) distance. The most frequently encountered mite species were Veigaia nemorensis, Parazercon radiatus and Zercon zelawaiensis.     

Assessment of movements and habitat use of <Emphasis Type="Italic">Salmo opimus</Emphasis> in Fırnız stream,river Ceyhan of Turkey using radio telemetry techniques

This study was carried out to provide information about movement and habitat use by an endemic Salmonid species (Salmo opimus Turan et al. Ichthyol Explor Freshw 23: 219–236, Turan et al. 2012) in F?rn?z Stream, a tributary of River Ceyhan in Turkey, using manual tracking as a radio telemetry technique. During the study, 19 of the 23 tagged trout were relocated by eight to 20 times (mean: 15 relocations per fish) in F?rn?z Stream. The time between the tracking surveys and relocations varied from 21 to 44 days (mean: 30 days) and the mean distance between relocations was 151 m (26 to 881 m). Tagged trout showed a distribution within a distance of 9350 m in F?rn?z Stream. 95% of the relocations clustered at a distance of 4500 m, while 75 and 50% of them were distributed at a distance of 1935 m and 1488 m, respectively. The linear home range of the individual ranged from 199 to 5087 m (mean 792 m), whereas mean 95% Kernel Density Home Range (KDHR), 75% KDHR, and mean core range (50% KDHR), were 632 m, 477 m and 290 m, respectively. The depths and velocities of the locations where tagged trout occurred varied from 20 to 185 cm (mean depth: 43 cm) and 11 to 240 cm/s (mean velocity: 45.9 cm/s). There was no correlation between fish size and depth and fish size and velocity. Hydropower stations and trout farms negatively affected movement of the brown trout in the stream. The fish passage in F?rn?z Hydropower Station (HPP) is inefficient due to low water mark downstream. Thus, all the obstructions that prevent fish movements must be arranged to enable fish passage in F?rn?z Stream in order to preserve the brown trout population in the stream.     

Edge effects in a three-dimensional world: height in the canopy modulates edge effects on the epiphyte Sarmienta repens (Gesneriaceae)

In fragmented landscapes, the sharp transitions between remnant habitats and those created by human disturbances result in “edge effects”. Changes in microhabitat characteristics (for example, the height at which epiphytic plants grow on their host trees) may, however, modulate these effects. We evaluated how distance to the edge and height on the host tree affect seed germination and adult occurrence of the austral-forest epiphyte Sarmienta repens. The negative effect of edges on germination and adult occurrence was modulated by a vertical gradient (height) with contrasting effects on seed germination and survival to adulthood. Seed germination was affected by both height and distance to the forest edge, increasing away from forest edges for plants growing on trees in mid-story (3–6 m) and canopy zones (6–12 m) but being unaffected by the distance to the edge for plants located in understory zones (<3 m above the ground). Adult occurrence, in contrast, increased with both height and distance to the edge. As a result, seeds deposited near edges germinated best at a microhabitat (understory zone) inadequate for subsequent survival. Our results stress the importance of maintaining intact forest areas, free from edge influences and hosting large trees, to preserve the rich epiphytic flora characteristic of humid forests.     

Unraveling the complex genetic model for cystic fibrosis: pleiotropic effects of modifier genes on early cystic fibrosis-related morbidities

The existence of pleiotropy in disorders with multi-organ involvement can suggest therapeutic targets that could ameliorate overall disease severity. Here we assessed pleiotropy of modifier genes in cystic fibrosis (CF). CF, caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene, affects the lungs, liver, pancreas and intestines. However, modifier genes contribute to variable disease severity across affected organs, even in individuals with the same CFTR genotype. We sought to determine whether SLC26A9, SLC9A3 and SLC6A14, that contribute to meconium ileus in CF, are pleiotropic for other early-affecting CF co-morbidities. In the Canadian CF population, we assessed evidence for pleiotropic effects on (1) pediatric lung disease severity (n = 815), (2) age at first acquisition of Pseudomonas aeruginosa (P. aeruginosa) (n = 730), and (3) prenatal pancreatic damage measured by immunoreactive trypsinogen (n = 126). A multiple-phenotype analytic strategy assessed evidence for pleiotropy in the presence of phenotypic correlation. We required the same alleles to be associated with detrimental effects. SLC26A9 was pleiotropic for meconium ileus and pancreatic damage (p = 0.002 at rs7512462), SLC9A3 for meconium ileus and lung disease (p = 1.5 × 10^?6 at rs17563161), and SLC6A14 for meconium ileus and both lung disease and age at first P. aeruginosa infection (p = 0.0002 and p = 0.006 at rs3788766, respectively). The meconium ileus risk alleles in SLC26A9, SLC9A3 and SLC6A14 are pleiotropic, increasing risk for other early CF co-morbidities. Furthermore, co-morbidities affecting the same organ tended to associate with the same genes. The existence of pleiotropy within this single disorder suggests that complementary therapeutic strategies to augment solute transport will benefit multiple CF-associated tissues.     

High-level soluble expression of one model olfactory receptor (ODR-10) in Escherichia coli cell-free system

High-level production of G protein-coupled receptors (GPCRs) is usually difficult to achieve in heterologous cell systems. The inherent hydrophobicity of these receptors could cause aggregation and possible cytotoxicity. Cell-free (CF) expression has become a highly promising tool for the fast and efficient production of integral membrane proteins. Here we reported the CF production of an olfactory receptor from Caenorhabditis elegans, odorant response abnormal protein 10 (ODR-10), a member of GPCRs, using the Escherichia coli extracts. Different expression vectors were investigated and 175 μg/ml total ODR-10 was achieved with pIVEX2.4c. To obtain soluble ODR-10, different detergents and liposome with varied concentrations were respectively added into the CF system. High-level expression of soluble ODR-10 (150 μg/ml) was attained with the addition of 1.5 % polyoxyethylene-(20)-cetyl-ether (Brij58) into the CF system. Furthermore, the yield of total ODR-10 was improved to 350 μg/ml by supplementing liposomes into the CF system, and the maximal concentration of the soluble receptor (102 μg/ml) was achieved in this liposome-assisted CF system. Both strategies produced ODR-10 efficiently by using CF system, and the direct reconstitution of the in vitro expressed receptor into liposomes will be preferred for its potential applications in many areas.     

Nitrogen biogeochemistry of a mature Scots pine forest subjected to high nitrogen loads

Nitrogen (N) biogeochemistry of a mature Scots pine (Pinus sylvestris L.) stand subjected to an average total atmospheric N deposition of 48 kg ha^?1 year^?1 was studied during the period 1992–2007. The annual amount of dissolved inorganic nitrogen (DIN) in throughfall (TF) averaged 34 kg ha^?1 year^?1 over the 16-year monitoring period. The throughfall fluxes contained also considerable amounts of dissolved organic nitrogen (DON) (5–8.5 kg N ha^?1 year^?1), which should be incorporated in the estimate of N flux using throughfall collectors. Throughfall DIN fluxes declined at a rate of ?0.9 kg N ha^?1 year^?1, mainly due to the decreasing TF fluxes of ammonium (NH₄), which accounted for 70% to TF DIN. The decrease in TF DIN was accompanied by a decrease in DIN leaching in the seepage water (?1.6 kg N ha^?1 year^?1), which occurred exclusively as nitrate (NO₃ ^?). Nitrate losses in the leachate of the forest floor (LFH) equalled the TF NO₃ ^? delivered to the LFH-layer. On the contrary, about half of the TF NH₄ ⁺ was retained within the LFH-layer. Approximately 60% of the TF DIN fluxes were leached indicating that N inputs were far in excess of the N requirements of the forest. For DON, losses were only substantial from the LFH-layer, but no DON was leached in the seepage water. Despite the high N losses through nitrate leaching and NO _x emission, the forest was still accumulating N, especially in the aggrading LFH-layer. The forest stand, on the contrary, was found to be a poor N sink.     

Establishment of a turbot fin cell line and its susceptibility to turbot reddish body iridovirus

A turbot, Scophthalmus maximus, fin (TF) cell line was established and susceptibility to turbot reddish body iridovirus (TRBIV) was determined in this study. Primary culture of TF cells was initiated from fin tissue pieces partially digested with trypsin, collagenase II and hyaluronidase. Digested tissue pieces were cultured at 24 °C in Leibovitz-15 medium (pH 7.2), supplemented with 20% fetal bovine serum, carboxymethyl chitosan, N-acetylglucosamine hydrochloride, basic fibroblast growth factor and epidermal growth factor. The cultured TF cells, in fibroblast shape, proliferated to 100% confluency 50 days later. A TF cell line, with a population doubling time of 45.6 h at passage 80, has been established and subcultured to passage 133. Chromosome analyses indicated that the TF cells exhibited chromosomal aneuploidy with a modal chromosome number of 44 which displayed the normal diploid karyotype of S. maximus at least up to passage 80. TRBIV susceptibility testing demonstrated that cytopathic effect and propagated viral particles were observed in TF cells after TRBIV infection. In conclusion, a continuous TRBIV susceptible TF cell line has been established successfully, and the cell line may serve as a valuable tool for studies of cell-virus interactions and has applications for different kinds of cytotechnological studies as well.     

Thinning affects Pinus sylvestris needle decomposition rates and chemistry differently depending on site conditions

Changes in mass and chemical composition of Pinus sylvestris senescent needles were studied over a 5 year period in Mediterranean (MF) and Continental forests (CF) in the Pyrenees under varying levels of thinning (P0: reference, no thinning; P20: removal of 20% basal area, P30: removal of 30% basal area). Decomposition rates were higher in MF (k = 0.423 year^?1) than in CF (k = 0.245 year^?1). However, the maximum decomposition limit was higher in MF (87.9%) compared to CF (78.1%). The relative importance and timing of rainfall, and cellulose and lignin abundance on the decomposition process was similar among both sites. However, air temperature and degree-days only affected CF (the colder site) during the initial stages of decomposition, while litter moisture was significant only in MF (the drier site) in the latter stages of decomposition. Nutrient and carbon dynamics showed temporal patterns similar to those reported in higher latitudes (except for Ca), however, indicators of N mineralization such as C/N and lignin/N at the study sites were lower than values reported in the literature. Decreases in decomposition rates after thinning were higher in MF than in CF, indicating that this ecosystem could, in the short term, be more sensitive to human intervention. Thinning had similar temporary qualitative effects at both sites, slowing decomposition, increasing N and P immobilization and decreasing Ca immobilization. However, quantitative effects of thinning were site dependent in that the magnitude of nutrient immobilization was higher in CF. A conceptual model is presented to explain effects of thinning on litter N dynamics. These temporary changes are not trivial as nutrient immobilization and accumulated organic matter losses over a thinning cycle may affect tree growth particularly during short rotations and intensive fast-growing plantations. Under similar nutrient availability conditions, sites where nutrient release occurs faster may show higher post-thinning tree growth rates.     

Microencapsulation by spray drying of nitrogen-fixing bacteria associated with lupin nodules

Plant growth promoting bacteria and nitrogen-fixing bacteria (NFB) used for crop inoculation have important biotechnological potential as a sustainable fertilization tool. However, the main limitation of this technology is the low inoculum survival rate under field conditions. Microencapsulation of bacterial cells in polymer matrices provides a controlled release and greater protection against environmental conditions. In this context, the aim of this study was to isolate and characterize putative NFB associated with lupin nodules and to evaluate their microencapsulation by spray drying. For this purpose, 21 putative NFB were isolated from lupin nodules and characterized (16S rRNA genes). Microencapsulation of bacterial cells by spray drying was studied using a mixture of sodium alginate:maltodextrin at different ratios (0:15, 1:14, 2:13) and concentrations (15 and 30 % solids) as the wall material. The microcapsules were observed under scanning electron microscopy to verify their suitable morphology. Results showed the association between lupin nodules of diverse known NFB and nodule-forming bacteria belonging to Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria and Bacteroidetes. In microencapsulation assays, the 1:14 ratio of sodium alginate:maltodextrin (15 % solids) showed the highest cell survival rate (79 %), with a microcapsule yield of 27 % and spherical microcapsules of 5–50 µm in diameter. In conclusion, diverse putative NFB genera and nodule-forming bacteria are associated with the nodules of lupine plants grown in soils in southern Chile, and their microencapsulation by spray drying using sodium alginate:maltodextrin represents a scalable process to generate a biofertilizer as an alternative to traditional nitrogen fertilization.     

Minor habituation to repeated experimental approaches in Scandinavian wolves

Large carnivores may become dangerous if they habituate to humans. We repeatedly approached wild wolves Canis lupus throughout a year to test their individual response to human encounters (N?=?141 trials). None of the at least 25 wolves present during the study visually or vocally exposed themselves. The wolves fled at a mean distance of 248?±?SE 11 m (range, 35–488 m). Their tolerance was most strongly influenced by the presence of site-dependent pups, while the distance at which they were initially alerted was most strongly influenced by detectability of human (wind and noise). The mean alert distance was 324?±?19 m in the first and 264?±?17 m in subsequent within-day trials, while tolerance distances showed no such trend, neither within a day nor throughout the year. The study indicates a high level of individual plasticity, making habituation difficult to predict.     

Determining the influence of environmental and patient specific factors on the polymicrobial communities of the cystic fibrosis airway

The aim of this study was to investigate the polymicrobial communities in an adult Cystic Fibrosis population stratified by gender and the most common CFTR mutation, F508del. In this pilot study, DNA was extracted from sputum samples of 29 adult patients (16 male: 13 female) with an F508del mutation in a stable clinical state. Universal primers were used to amplify DNA from bacterial and fungal communities and the resulting fragments were analysed by denaturing gradient gel electrophoresis. Bacterial profiles showed a significant effect of gender (P = 0.046) and P. aeruginosa carriage (P = 0.034) on community structure. Bacterial communities were found to be randomly assembled. Fungal community analysis found that F508del homozygous patients had a greater diversity than heterozygous patients (P = 0.007). This study indicates that the bacterial lung communities of adult CF patients are randomly assembled but have distinct gender based differences. Furthermore, the fungal communities colonising the CF lung are more diverse in F508 homozygotes. This is the first paper to identify a reduced bacterial diversity in female patients with CF and to implicate more severe CFTR genotypes with increased risk of infection with multiple fungal species.     

Early Clonal Survival and Growth of Poplars Grown on North Carolina Piedmont and Mountain Marginal Lands

The western half of North Carolina has abundant marginal pasturelands that vary greatly in altitude. Studies have demonstrated high Populus productivity on coastal plains and eastern Piedmont regions. Our objective was to identify best-performing Populus clones on marginal pasturelands representing upper Piedmont (Salisbury, 215 m above sea level, m.a.s.l.), northern Blue Ridge Mountains (Laurel Springs, 975 m.a.s.l.), and southern Blue Ridge Mountains (Mills River, 630 m.a.s.l.). At Salisbury, height and basal diameter (BD) were significantly related to clones (p?<?0.0001), and some clones were affected by clone-spacing interaction while spacing affected aboveground wood volume significantly (p?<?0.0001). At Mills River, clonal survival (p?<?0.0011), height, and volume (p?<?0.0051) varied with contrasting significance of some clonal differences between spacings. At Laurel Springs, survival varied among clones in 1 m?×?1 m spacing (p?=?0.003) but not 2 m?×?2 m spacing while heights and volumes differed in both spacings (p?<?0.0058). Clone 185 was consistently in the top 10 % for height, BD, and survival at all sites and spacings while other clones performed variably. Height-BD regressions were affected by clones, spacing, and sites. Volume had no clear correlations with precipitation, photosynthetically active radiation, temperature, and altitude across sites while height correlated with precipitation. Our results compared favorably with published results in other US regions, and show short rotation poplars have efficacy in Piedmont and mountain regions if the right clones in terms of growth/productivity, survival, and disease resistance are selected. Larger clonal performance variations are expected as competition increases, and highlight importance of experimentally determining suitable clones for specific sites.     

A modified rinsing method for the determination of the S,W–S and D + U fraction of protein and starch in feedstuff within the in situ technique

A modified rinsing method for the in situ technique was developed to separate, isolate and characterise the soluble (S), the insoluble washout (W–S) and the non-washout fractions (D + U) within one procedure. For non-incubated bags (t = 0 h), this method was compared with the conventional, Combined Fractionation (CF) method that measures the D + U and S fractions in separate steps and subsequently calculates the W–S fraction. The modified method was based on rinsing of nylon bags in a closed vessel containing a buffer solution (pH 6.2) during 1 h, where shaking speeds of 40, 100, and 160 strokes per minutes (spm) were evaluated, and tested for six feed ingredients (faba beans, maize, oats, peas, soya beans and wheat) and four forages (two ryegrass silages and two maize silages). The average recoveries as the sum of all fractions were 0.972 ± 0.041 for N and 0.990 ± 0.050 for starch (mean ± s.d.). The mean W–S fraction increased with increasing shaking speed and varied between 0.017 (N) and 0.083 (starch) at 40 spm and 0.078 (N) and 0.303 (starch) at 160 spm, respectively. For ryegrass silages, the W–S fraction was absent at all shaking speeds, but was present in the CF method. The modified method, in particular at 40 and 100 spm, reduced the loss of small particles during rinsing, resulting in lower W–S and higher D + U fractions for N and starch compared with the CF method. For soya beans and ryegrass silage, the modified method reduced the S fraction of N compared with the CF method. The results obtained at 160 spm showed the best comparison with those from the CF method. The W–S fraction of the feedstuff obtained at 160 spm contained mainly particles smaller than 40 μm (0.908 ± 0.086). In most feedstuff, starch was the most abundant chemical component in the W–S fraction and its content (726 ± 75 g/kg DM) was higher than in the D + U fraction (405 ± 177 g/kg DM). Alkaline-soluble proteins were the dominant N-containing components in the W–S fraction of dry feed ingredients and its relative content (0.79 ± 0.18 of total N in W–S) was higher than in the D + U fraction (0.59 ± 0.07 of total N in D + U) for all feedstuff except maize. The molecular weight distribution of the alkaline-soluble proteins differed between the W–S and the D + U fractions of all dry feed ingredients, except soya beans and wheat.     

Characterization of <Emphasis Type="Italic">Staphylococcus aureus</Emphasis> isolates from pediatric patients with cystic fibrosis

Staphylococcus aureus is one of the major respiratory pathogens associated with cystic fibrosis (CF) patients. In this study, we collected sputum and isolated fifty S. aureus isolates from CF patients with the median age of 9.5 years old. Then we determined the profiles of these isolates by antibiotic susceptibility testing, examining their cytotoxicity and ability to internalize into an epithelial cell line (A549), as well as multiple loci sequencing typing. Predominant CF S. aureus isolates were resistant to penicillin; however, these isolates were sensitive to various antibiotics, such as vancomycin and minocycline. Different CF S. aureus isolates showed distinct cytotoxic activities, and 90 % of CF S. aureus isolates possessed the enterotoxin genes, sea and hlg. Moreover, we found that multiple different CF S. aureus isolates appeared to have the distinct capacity of invading A549 cells. ST5 (14 %), ST30 (14 %), and ST8 (10 %) were prevalent ST types in these isolates. Further analysis revealed that ST5 and ST30 isolates were less toxic than ST8 and ST15 isolates, and that the ST5, ST15, ST59, and ST87 types of CF S. aureus were less capable of invading A549 cells. Our results suggest that the ST typing method may be useful in predicting cytotoxicity and the invading capacity of S. aureus isolates from patients with CF.     

Effects of adjuvant and conidial concentration on the efficacy of <Emphasis Type="Italic">Beauveria bassiana</Emphasis> for the control of the two spotted spider mite, <Emphasis Type="Italic">Tetranychus urticae</Emphasis>

Greenhouse experiments were conducted on various crops (cucumber, tomato, eggplant, green bean) to ascertain the effects of Break-thru^® (polyether-polymethylsiloxane-copolymer, a silicone surfactant) and an oil emulsion, on Beauveria bassiana (Balsamo) Vuillemin (Bb) applications for the control of the two spotted spider mite, Tetranychus urticae Koch. The objectives were to compare a) the efficacy of Bb control when applied in aqueous Break-thru^® or an oil emulsion; b) the effects of various concentrations of Bb conidia, as affected by each surfactant; and c) the effects of Break-thru^® on the activity of the fungus. Conidia were suspended either in an aqueous Break-thru^® or an emulsifiable formulation at different conidial concentrations (1.05 × 10⁶, 2.1 × 10⁶ and 4.2 × 10⁶ conidia ml^?1) and sprayed onto leaves 2 weeks after artificial pest inoculation. Two sprays were performed, with an interval of one week from one spray to another, and T. urticae population counts (both motile and egg stages) were made on plant leaves 7 days after each spray. Bb conidia in Break-thru^® were more efficacious than conidia in emulsifiable formulation. With the highest rate of conidia (4.2 × 10⁶ conidia ml^?1), mortality of adult mites ranged from 60 ± 4.2 (mean ± SE) to 85.7 ± 4.3% in the Break-thru^® suspension and 39.4 ± 7 to 61.3 ± 6% in the oil emulsion. Leaf damage index was also substantially reduced from 70% in the unsprayed control to 40% by the application of Bb conidia at the highest rate with Break-thru^®. Break-thru^® can be combined with Bb in the integrated management of T. urticae and Isolate R444 is a promising candidate for the control of the pest.     

Dispersal Capacity and Behavior of Nymphal Stages of Halyomorpha halys (Hemiptera: Pentatomidae) Evaluated Under Laboratory and Field Conditions

The invasive brown marmorated stink bug, Halyomorpha halys (Stål) (Hemiptera: Pentatomidae), is a highly polyphagous and mobile pest causing crop damage aggregated at the perimeters of crop fields. Understanding the dispersal biology of H. halys is critical for the development of reliable monitoring and management strategies. In this study, dispersal ecology of H. halys nymphs was studied under laboratory and field conditions. In the laboratory, horizontal and vertical walking capacity was quantified for mobile nymphal stages (i.e., 2nd through 5th instars) and compared with adults. There was a significant difference in the horizontal distance moved by H. halys among the life stages tested. Third instars exhibited significantly greater walking distances compared with adults; horizontal walking distances by other nymphal stages were not significantly different from adults. A similar pattern was observed from vertical climbing tests of H. halys. Third and 4th instars climbed significantly greater distances compared with 2nd instars and adults, while distances climbed by 5th instars were intermediate. In the field, the walking distance of 3rd and 5th instar nymphs on mowed grass was quantified based on direct observation of individuals for 30 min. Under these conditions, 5th instars moved nearly two-fold greater distances compared with 3rd instars, but surface temperature affected both nymphal stages similarly. Shorter bouts of movement were common at surface temperatures below 25 °C, whereas individuals showed longer walking distances above 25 °C. In mark-release-recapture studies, 4th and 5th instars were released and recaptured in traps baited with attractive pheromonal-based stimuli to estimate dispersal rates under field conditions. When insects were released 5 m from traps, both instars were first recaptured within 2 h after release, with the recapture rates of 54 and 69 % for 4th and 5th instars over 24 h, respectively. When insects were released 20 m from traps, 4th and 5th instars were first recaptured in less than 5 h, with the recapture rates of 27 and 51 %, respectively. The results of this study indicate that H. halys nymphs have strong dispersal capacity with which populations can easily move among host plants and other attractive stimuli at farmscape levels.     

Short-distance pollen dispersal and high self-pollination in a bat-pollinated neotropical tree

We investigated pollen dispersal and breeding structure in the tropical tree species Caryocar brasiliense Camb. (Caryocaraceae), using genetic data from ten microsatellite loci. All adult trees (101) within a patch of 8.3 ha were sampled, and from these adults 18 open-pollinated maternal progeny arrays were analyzed (280 seeds from 265 fruits). Most fruits presented only one seed (median equal to 1.000) and mean number of ripened seeds per fruit was 1.053 (SD?=?0.828). Our results showed that C. brasiliense presents a mixed-mating system, with 11.4% of self-pollination, multilocus outcrossing rate of t _m?=?0.891?±?0.025, and high probability of full-sibship within progeny arrays (r _p?=?0.135?±?0.032). Outcrossing rate and self-pollination varied significantly among mother trees. We could detect a maximum pollen dispersal distance of ～500 m and a mean pollen dispersal distance of ～132 m. However, most pollination events (80%) occurred at distances less than 200 m. Our results also indicated that pollen dispersal is restricted to a neighborhood of 5.4 ha with rare events of immigration (～1% N _e m?=?0.35). C. brasiliense also presents a significant but weak spatial genetic structure (Sp?=?0.0116), and extension of pollen dispersal distance was greater than seed dispersal (N _b?=?86.20 m). These results are most likely due to the foraging behavior of pollinators that may have limited flight range. The highly within-population synchronous flowering, high population density, and clumped distribution reinforce pollinator behavior and affect residence time leading to a short-distance pollen dispersal.     

Pattern of immigration of the sorghum plant bug Stenotus rubrovittatus (Hemiptera: Miridae) into paddy fields from a large source habitat

Evaluation of the landscape-level movement of Stenotus rubrovittatus (Matsumura), a major rice pest in Japan, is essential for establishing management strategies. We assessed the immigration timing and the average dispersal distance from a bank slope covered with Italian ryegrass Lolium multiflorum Lam. to paddy fields by periodic sampling in two regions in Chiba Prefecture. The immigrant densities in paddy fields increased exponentially as they approached the bank slope as a large-scale habitat of the insect. The relationship between immigrant density and distance from the source habitat fit an empirical model and theoretical model well. The theoretical model estimated the average dispersal distance during immigration: that of females was 72.0 and 92.1 m and that of males was 122.0 and 112.9 m in the respective regions. In addition, the average dispersal distance of males increased 7 days or later after the rice heading date despite the steady dispersal distance of females.