DISSEMINATION OF HOWARDULA SP. NEMATODES BY ADULT TOBACCO FLEA BEETLES (COLEOPTERA: CHRYSOMELIDAE)

1977 ◽  
Vol 109 (9) ◽  
pp. 1283-1285 ◽  
Author(s):  
Kent D. Elsey
Keyword(s):  
Adult Male ◽  
Average Rate ◽  
Flea Beetle ◽  
Nematode Parasite ◽  
Free Living ◽  
Flea Beetles ◽  
The Mean

AbstractA Howardula sp. nematode parasite of the tobacco flea beetle, Epitrix hirtipennis (Melsheimer), was able to utilize the adult male to disseminate juveniles. At 27°C the mean total number of juveniles released per beetle was 369 for female beetles and 377 for males at an average rate of ca. 37 per day from both sexes. A cooler temperature retarded the onset of dissemination but did not affect the rate of release. Fifty-nine per cent of the free-living nematodes survived for 5–6 days, but none survived beyond 13 days. Seventy-nine per cent of the free-living nematodes were female.

THE SPATIAL DISTRIBUTION OF SPRING AND SUMMER POPULATIONS OF ADULT POTATO FLEA BEETLES, EPITRIX CUCUMERIS (HARRIS) (COLEOPTERA: CHRYSOMELIDAE), ON SMALL PLOTS OF POTATOES

1989 ◽  
Vol 121 (12) ◽  
pp. 1097-1101 ◽  
Author(s):  
Jeff G. Stewart ◽  
Leith S. Thompson
Keyword(s):  
Spatial Distribution ◽  
Flea Beetle ◽  
Regression Equations ◽  
Flea Beetles ◽  
Mean Crowding ◽  
The Mean ◽  
Potato Flea Beetle

AbstractThe spatial distribution of spring and summer populations of the potato flea beetle, Epitrix cucumeris (Harris) (Coleoptera: Chrysomelidae), on potatoes (“Superior” variety) was studied in 1987 and 1988. Slopes of the regression of mean crowding on the mean number of adults per plant were not significantly different from 1.0 except for summer populations in 1988. The y-intercepts of these regression equations were not significantly different from 0, suggesting that adults of the potato flea beetle are not aggregated. The ratios of mean crowding to mean number of adults per plant were 0.81 for spring populations and 1.02 for summer populations, also indicating that the populations were not highly aggregated. With a level of precision of 0.25, 10 samples per plot were appropriate when more than 2.8 adults per plant were present in the spring and when more than 7.2 adults per plant were present in the summer.

PATTERNS OF FEEDING INJURY TO POTATO BY THE POTATO FLEA BEETLE (COLEOPTERA: CHRYSOMELIDAE) IN MANITOBA

1996 ◽  
Vol 128 (5) ◽  
pp. 791-804
Author(s):  
S.F. Pernal ◽  
D.G. Senanayake ◽  
N.J. Holliday
Keyword(s):  
Vertical Distribution ◽  
Repeated Measures ◽  
Seasonal Pattern ◽  
Flea Beetle ◽  
Control Measures ◽  
Potato Plants ◽  
Flea Beetles ◽  
The Mean ◽  
The Vertical Distribution ◽  
Potato Flea Beetle

AbstractThe amount and distribution of foliar feeding injury by adult potato flea beetles, Epitrix cucumeris (Harris), were examined on individually caged potato plants grown in field plots in Manitoba. Plants were either maintained as uninfested controls, or were exposed throughout the growing season to different insect densities that mimicked the natural seasonal pattern of infestation. In 1984, a trial was conducted using cv. ‘Norland’ exposed to four different densities of potato flea beetles. In 1989 and 1990, cv. ‘Russet Burbank’ was exposed to potato flea beetles, and in some treatments, plants were exposed to early summer infestations of Colorado potato beetles, Leptinotarsa decemlineata (Say). In each trial, during the late summer period of high potato flea beetle density, the amount and distribution of flea beetle feeding injury were assessed at weekly intervals. Counts of feeding punctures in single leaflets were made from leaves in the upper, middle, and lower third of each caged plant, and these data were subjected to repeated measures analysis of variance. In each of the 3 years, increasing the number of flea beetles increased the mean number of feeding punctures per leaflet in an approximately linear fashion; however, the number of punctures per beetle varied between cultivars and years. In 1984 and 1990, the number of feeding punctures per leaflet was least in the upper third of the plants, and greater in the lower, or middle and lower, third of plants. However, in 1989, the vertical distribution of feeding punctures was relatively even. Previous feeding by Colorado potato beetles increased the mean number of flea beetle feeding punctures per leaflet and changed the vertical distribution of feeding punctures. Rainfall and temperature were correlated with patterns of flea beetle injury; injury was concentrated on lower leaflets during weeks of greater rainfall, and upper leaflets were injured most during weeks with higher average temperatures. It is concluded that flea beetles exhibit preferences for feeding in specific portions of potato plants, and that these preferences change in response to previous defoliation and are influenced by meteorological conditions. Consequently, counting feeding punctures would not be a reliable method of assessing whether control measures for potato flea beetles are justified.

HAPTEN-RADIOIMMUNOASSAY OF PLASMA OESTRADIOL

1973 ◽  
Vol 72 (2) ◽  
pp. 330-344 ◽  
Author(s):  
Peter Doerr
Keyword(s):  
Adult Male ◽  
Normal Values ◽  
Normal Adult ◽  
Adult Males ◽  
Reagent Blank ◽  
Keyhole Limpet Haemocyanin ◽  
Ether Extraction ◽  
The Mean ◽  
Assay Precision ◽  
Plasma Oestradiol

ABSTRACT A hapten-radioimmunoassay for plasma oestradiol is described and information about the reliability of the method is given in detail. Oestradiol-3-hemisuccinate coupled to keyhole limpet haemocyanin is used for immunization of rabbits. The antiserum utilized for the assay is characterized by its titer, affinity and specificity. Following ether extraction and NaOH-light petroleum partition oestradiol is separated from crossreacting oestrogens by TLC. Oxidation of oestradiol on the plate is prevented by mercaptoethanol. To separate free and antibody bound ligand 250 μg dextran-coated charcoal per tube is used in the presence of bovine serum gammaglobulin (1 mg/ml). The between-assay precision based on 15 different determinations of control samples from normal adult male plasma was 9.4% (C. V.). The mean reagent blank value of 31 determinations was equivalent to 0.3 pg oestradiol and the detection limit in terms of the 99% confidence limit for a single blank value, was equivalent to 4.3 pg oestradiol. A procedure for detecting plasma blanks is described. Plasma oestradiol is separated from approximately all concomitant substances originally present in the sample by enzymatic conversion into oestrone and a second TLC. No plasma blanks could be detected with respect to normal adult male plasma. Normal values for adult males based on 51 subjects were characterized by a median of 17.2 pg/ml and the 95 percentiles of 9.5–27.6.

scholarly journals Objective measurement of physical activity in Macaca fascicularis

1982 ◽  
Vol 16 (3) ◽  
pp. 240-243
Author(s):  
Wayne T. Corbett ◽  
Harry M. Schey ◽  
A. W. Green
Keyword(s):  
Physical Activity ◽  
Standard Deviation ◽  
Macaca Fascicularis ◽  
Living Environment ◽  
Activity Levels ◽  
Free Living ◽  
Activity Measurements ◽  
Active Intermediate ◽  
The Mean ◽  
The Relationship

The mean and standard deviation over 24 h for 3 groups of animals - active, intermediate and inactive - in physical activity units were 10948 ± 3360, 2611 ± 1973 and 484 ± 316 respectively. The differences were significant ( P = 0·004), demonstrating the ability of the method to distinguish between groups that can be visibly differentiated. The small within-animal physical activity standard deviation (18·85 PAU) obtained in another group, suggests that it also yields reliable physical activity measurements for non-human primates. The monitoring device used can discriminate between individual nonhuman primate physical activity levels in a free-living environment and does not alter daily behaviour. This makes possible the study of the relationship between physical activity and atherosclerosis in nonhuman primates.

Statistical analysis of nematode counts from interlaboratory proficiency tests

Nematology ◽  
2014 ◽  
Vol 16 (2) ◽  
pp. 229-243 ◽  
Author(s):  
Wim Van Den Berg ◽  
Olaf Hartsema ◽  
Loes J.M.F. Den Nijs
Keyword(s):  
Statistical Analysis ◽  
Proficiency Test ◽  
Meta Analysis ◽  
Proficiency Tests ◽  
Free Living ◽  
Accuracy And Precision ◽  
Mean And Variance ◽  
The Mean ◽  
Interaction Variance

A series of proficiency tests on potato cyst nematode (PCN; ) and free-living stages of Meloidogyne and Pratylenchus () were investigated to determine the accuracy and precision of the nematode counts and to gain insights into possible trends and potential improvements. In each test, each participating laboratory received ten samples of soil collected from naturally infested fields and well mixed before distribution. The variance between the counts from the ten samples, estimated per test and laboratory, was constant for PCN cysts and free-living stages of Meloidogyne spp. and Pratylenchus spp. during the period monitored. However, during the initial years, the variance between the samples showed a downward trend for PCN living juveniles. The variance between the laboratories, estimated per test, was constant for PCN cysts over the period 1994-2010. For PCN living juveniles the variance between laboratory means declined from 1994-2000 and from 2000 it was more or less constant, which coincided with the introduction of a well-described new methodology. For Meloidogyne spp. and Pratylenchus spp., from 1998-2005 the variance between laboratory means was more or less constant or increased. From 2006, all participating laboratories incubated the organic matter and the variance between the laboratories was stable and below the levels observed during 2003-2005. After discarding data from initial years with unstable variances of the nematode counts, a meta-analysis was carried out on the remaining data using HGLMs to model the mean and variance of the counts simultaneously. The within-laboratory variance for the ten samples and the interaction variance of test and laboratory were estimated and combined to percentage coefficient of variation (%CV) per laboratory. For PCN cysts, %CV per laboratory ranged from 12.6 to 41.6 and for PCN juveniles in sandy soil from 24.4 to 67.4 and in loamy soil from 37.9 to 102.0. For Meloidogyne spp., %CV ranged from 53.2 to 84.4 and for Pratylenchus spp. from 24.3 to 90.6. The quality of a proficiency test is largely defined by random distribution of the nematodes over the samples allocated, statistical analysis of the data and communication of the results to participating laboratories. This study provides insights into the accuracy and precision at laboratories in recent years and the effect of concerted actions during the period in which the proficiency tests were conducted.

scholarly journals Energy expenditure of free-living reindeer estimated by the doubly labelled water method

Rangifer ◽  
2000 ◽  
Vol 20 (2-3) ◽  
pp. 211 ◽  
Author(s):  
Geir Gotaas ◽  
Eric Milne ◽  
Paul Haggarty ◽  
Nicholas J.C. Tyler
Keyword(s):  
Energy Expenditure ◽  
Rangifer Tarandus ◽  
Water Flux ◽  
Co2 Production ◽  
Wild Ungulates ◽  
Free Living ◽  
Doubly Labelled Water ◽  
Svalbard Reindeer ◽  
Mountain Pasture ◽  
The Mean

The doubly labelled water (DLW) method was used to measure total energy expenditure (TEE) in three male reindeer (Rangifer tarandus tarandus) aged 22 months in winter (February) while the animals were living unrestricted at natural mountain pasture in northern Norway (69°20'N). The concentrations of 2H and l8O were measured in water extracted from samples of faeces collecred from the animals 0.4 and 11.2 days after injection of the isotopes. Calculated rates of water flux and CO2-production were adjusted to compensate for estimated losses of 2H in faecal solids and in methane produced by microbial fermentation of forage in the rumen. The mean specific TEE in the three animals was 3.057 W.kg-1 (range 2.436 - 3.728 W.kg1). This value is 64% higher than TEE measured by the DLW method in four captive, non-pregnant adult female reindeer in winter and probably mainly reflects higher levels of locomotor activity in the free-living animals. Previous estimates of TEE in free-living Rangifer in winter based on factorial models range from 3.038 W.kg-1 in female woodland caribou (R. t. caribou) to 1.813 W.kg-1 in female Svalbard reindeer (R. t. platyrhynchus). Thus, it seems that existing factorial models are unlikely to overestimate TEE in reindeer/caribou: they may, instead, be unduly conservative. While the present study serves as a general validation of the factorial approach, we suggest that the route to progress in the understanding of field energetics in wild ungulates is via application of the DLW method.

scholarly journals Quantifying the Feeding Periods Required by Corn Flea Beetles to Acquire and Transmit Pantoea stewartii

Plant Disease ◽  
2006 ◽  
Vol 90 (3) ◽  
pp. 319-324 ◽  
Author(s):  
B. Menelas ◽  
C. C. Block ◽  
P. D. Esker ◽  
F. W. Nutter
Keyword(s):  
Nalidixic Acid ◽  
Growth Models ◽  
Flea Beetle ◽  
Feeding Time ◽  
Feeding Period ◽  
Selective Media ◽  
Pantoea Stewartii ◽  
Flea Beetles ◽  
Time Required ◽  
The Relationship

The feeding periods required by corn flea beetles to acquire and transmit Pantoea stewartii were investigated in the Stewart's disease of corn pathosystem. To quantify the effect of acquisition feeding period on percentage of acquisition, field-collected corn beetles were allowed to feed for 6, 12, 24 36, 48, and 72 h on corn seedlings previously inoculated with a rifampicin- and nalidixic acid-restraint strain of P. stewartii. Acquisition of P. stewartii by corn flea beetles was considered positive if the rifampicin- and nalidixic acid-marked strain was recovered on selective media. To quantity the effect of transmission feeding period on percent transmission of P. stewartii by corn flea beetles, P. stewartii- infested corn flea beetles were allowed to feed on healthy corn seedlings for periods of 3, 6, 12, 24, 36, 48, and 72 h. After the appropriate transmission feeding period, leaf tissues surrounding the sites of feeding scars were cultured for the presence of the P. stewartii-marked strain. Transmission of P. stewartii was considered positive if the marked strain was recovered on selective media. Acquisition of P. stewartii occurred within 6 h and the percentage of corn flea beetles that had acquired P. stewartii after 72 h ranged from 68 to 94%. The change in P. stewartii acquisition by corn flea beetles (Y) with respect to acquisition feeding period (X) was best described by the Gompertz model, with R2 values ranging from 91 to 99%. The mean time for acquisition by 50% of the corn flea beetles was 36.5 ± 11.6 h. The minimum transmission feeding time required for corn flea beetles to transmit P. stewartii following a 48-h acquisition feeding period was less than 3 h. The percent transmission of P. stewartii by corn flea beetles was nearly 100% after a 48-h transmission feeding period and was 100% by 72 h. Among population growth models evaluated, the monomolecular model best described the relationship between percent transmission (Y) and transmission feeding periods (X), with R 2 values of up to 84%. However, a nonlinear form of the monomolecular model better quantified the relationship between percent transmission and transmission feeding period, because pseudo-R2 values ranged between 98.1 and 99.5%. The predicted transmission feeding time required for 50% of P. stewartii-infested corn flea beetles to transmit the pathogen was 7.6 ± 0.87 h. These results suggest that the corn flea beetle is a highly efficient vector that can quickly acquire and transmit P. stewartii, thereby requiring insecticide seed treatments and foliar insecticides that act quickly to prevent corn flea beetles from acquiring and transmitting P. stewartii to corn plants.

Assessment of the MyWellness Key accelerometer in people with type 2 diabetes

2015 ◽  
Vol 40 (11) ◽  
pp. 1193-1198 ◽  
Author(s):  
Samantha Kate McGinley ◽  
Marni J. Armstrong ◽  
Farah Khandwala ◽  
Silvano Zanuso ◽  
Ronald J. Sigal
Keyword(s):  
Type 2 Diabetes ◽  
Normal Weight ◽  
Moderate Intensity ◽  
Exercise Session ◽  
Free Living ◽  
The Mean ◽  
Moderate Intensity Activity ◽  
The Right ◽  
Treadmill Protocol

Accelerometers are designed to measure physical activity (PA) objectively. The MyWellness Key (MWK) accelerometer has been validated primarily in younger, normal-weight populations. The aims of this study were to examine the accuracy of the MWK against directly measured lab-based exercise and free-living PA in people with type 2 diabetes, many of whom are older and overweight or obese. Thirty-five participants with type 2 diabetes completed the protocol, which included a laboratory-based session and a free-living phase. In the laboratory visit, participants completed a structured treadmill protocol wearing MWKs on each hip (all subjects) and bra cup (women only). The speed where each MWK switched from recording light- to moderate-intensity activity was determined for each MWK worn. In the free-living phase, participants wore the MWK for all waking hours for 2 weeks, and recorded exercise in PA diaries immediately after each exercise session. The mean cut-points between low (“Free”) and moderate (“Play”) intensity for the right and left waist-worn MWKs were 4.1 ± 0.5 km/h and 5.0 ± 0.9 km/h for the bra-mounted MWK; ideal cut-point would be 4.0 km/h. In the free-living phase, the Spearman correlation between PA according to PA diary and the waist-worn MWK was 0.81 (95% confidence interval (CI): 0.76, 0.85; P < 0.001), but only 0.66 (95% CI: 0.53, 0.77; P < 0.001) when on the bra. In conclusion, the waist-worn MWK measured PA volume accurately, and was acceptably accurate at discriminating between low- and moderate-intensity PA in people with type 2 diabetes. The MWK underestimated PA volume and intensity when worn on a bra.

Growth and Normal Puberty

PEDIATRICS ◽  
1998 ◽  
Vol 102 (Supplement_3) ◽  
pp. 507-511 ◽  
Author(s):  
Val Abbassi
Keyword(s):  
Adult Height ◽  
Average Rate ◽  
Final Height ◽  
Peak Height ◽  
Height Velocity ◽  
Peak Height Velocity ◽  
Pubertal Stage ◽  
Pubertal Growth ◽  
Velocity Peak ◽  
The Mean

We reviewed the growth characteristics of American boys and girls from published studies, including age at takeoff, age at peak height velocity, peak height velocity, duration of puberty, and the magnitude of the pubertal contribution to adult height. Age at takeoff is highly variable and sex-dependent. The mean takeoff age in children growing at an average rate is ∼11 years in boys and 9 years in girls, and peak height velocity occurs at a mean age of 13.5 years and 11.5 years, respectively, in these children. Whole-year peak height velocity is 9.5 cm/y in boys and 8.3 cm/y in girls, with slight variations in the different studies. The contribution of pubertal growth to final height is ∼30 to 31 cm in boys, accounting for 17% to 18% of the final height, and 27.5 to 29 cm in girls, accounting for 17% of the final height. The magnitude of pubertal growth has a negative correlation with age at takeoff, but no correlation with final height. Age at takeoff, however, correlates highly with pubertal stage, but correlates negatively with duration of puberty.

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