TOXICITY OF PERMETHRIN, AZINPHOSMETHYL, AND METHOMYL TO PHOLETESOR ORNIGIS (WEED) AND PHOLETESOR PEDIAS NIXON (HYMENOPTERA: BRACONIDAE), PARASITES OF THE SPOTTED TENTIFORM LEAFMINER, PHYLLONORYCTER BLANCARDELLA (FABR.) (LEPIDOPTERA: GRACILLARIIDAE)

1991 ◽  
Vol 123 (6) ◽  
pp. 1175-1182
Author(s):  
P.A. Fisher ◽  
J.E. Laing ◽  
D.J. Pree
Keyword(s):  
Consistent Difference ◽  
Pyrethroid Insecticides ◽  
Phyllonorycter Blancardella ◽  
The Difference ◽  
Pholetesor Ornigis ◽  
Laboratory Bioassays

AbstractThe toxicity of the insecticides permethrin, azinphosmethyl, and methomyl to adult Pholetesor ornigis (Weed) and P. pedias Nixon was evaluated in laboratory bioassays. Older P. pedias (2 and 3 days old) were more susceptible than younger parasites (1 day old) to permethrin. Azinphosmethyl was slightly more toxic to female P. ornigis than to male P. ornigis or to P. pedias. There was no consistent difference in the response of adult P. ornigis compared with P. pedias exposed to permethrin or methomyl on treated paper disks. Methomyl was twice as toxic as either azinphosmethyl or permethrin. Male P. ornigis were less susceptible than female P. ornigis to permethrin, but the difference was significant in only one of four populations tested. Male P. ornigis were less susceptible than females to azinphosmethyl. In 1986, populations of P. ornigis which had been exposed previously to pyrethroid insecticides were less susceptible to permethrin than P. ornigis from orchards where pyrethroids had never been applied. The response of both Pholetesor spp. to permethrin varied significantly from 1986 to 1987.

RELATIVE TOXICITY OF SIX INSECTICIDES TO MALE AND FEMALE PHOLETESOR ORNIGIS (WEED) (HYMENOPTERA: BRACONIDAE), A PARASITE OF THE SPOTTED TENTIFORM LEAFMINER, PHYLLONORYCTER BLANCARDELLA (FABR.) (LEPIDOPTERA: GRACILLARIIDAE)

1987 ◽  
Vol 119 (2) ◽  
pp. 153-157 ◽  
Author(s):  
R.M. Trimble ◽  
D.J. Pree
Keyword(s):  
Sexual Difference ◽  
Relative Toxicity ◽  
Control Potential ◽  
Pyrethroid Insecticides ◽  
Male And Female ◽  
Biological Control Potential ◽  
Phyllonorycter Blancardella ◽  
Low Levels ◽  
Two Populations ◽  
Pholetesor Ornigis

AbstractThe susceptibility of male and female Pholetesor ornigis (Weed) to the pyrethroid insecticides permethrin, fenvalerate, and deltamethrin, the organophosphorous insecticides azinphosmethyl and phosmet, and the carbamate insecticide methomyl, was compared in the laboratory using two populations from Norfolk County, Ontario. Female P. ornigis were more susceptible than males to permethrin. There was no sexual difference in the susceptibility of P. ornigis to the other five insecticides tested. The implications of these results for the biological control potential of P. ornigis in commercial apple orchards are discussed. The results obtained for permethrin, fenvalerate, azinphosmethyl, and methomyl were compared with those obtained in a study completed 6 years earlier using P. ornigis from another location in Ontario; the results suggest that P. ornigis from Norfolk County have low levels of resistance to permethrin (3.3-fold), fenvalerate (2.2-fold), and methomyl (4.1-fold).

scholarly journals ELECTROKINETIC PHENOMENA

1931 ◽  
Vol 14 (5) ◽  
pp. 563-573 ◽  
Author(s):  
H. A. Abramson ◽  
E. B. Grossman
Keyword(s):  
Streaming Potential ◽  
Experimental Comparison ◽  
Consistent Difference ◽  
Real Difference ◽  
Electrokinetic Phenomena ◽  
Egg Albumin ◽  
Streaming Potentials ◽  
The Difference

1. The conditions are described which are necessary for the comparison of certain types of electrokinetic potentials. An experimental comparison is made of (a) electrophoresis of quartz particles covered with egg albumin; and (b) similar experiments by Briggs on streaming potentials. A slight, consistent, difference is found between the electrophoretic potential and the streaming potential. This difference is probably due to the difference in the protein preparations used rather than to real difference in the electrophoretic and streaming potentials. 2. Data are given which facilitate the measurements and enhance the precision of the estimation of electrical mobilities of microscopic particles.

ABUNDANCE AND PHENOLOGY OF PARASITOIDS OF THE SPOTTED TENTIFORM LEAFMINER, PHYLLONORYCTER BLANCARDELLA (LEPIDOPTERA: GRACILLARIIDAE), IN CONNECTICUT

1984 ◽  
Vol 116 (3) ◽  
pp. 443-449 ◽  
Author(s):  
Chris T. Maier
Keyword(s):  
Pest Management ◽  
New Records ◽  
Critical Role ◽  
Seasonal Abundance ◽  
Relative Importance ◽  
Parasitoid Species ◽  
Native Parasitoids ◽  
Emergence Patterns ◽  
Phyllonorycter Blancardella ◽  
Pholetesor Ornigis

AbstractParasitoids of the trivoltine spotted tentiform leafminer, Phyllonorycter blancardella (Fabr.), were studied in Connecticut apple orchards to determine their relative importance, emergence patterns, and seasonal abundance. Sixteen parasitoid species, including 12 eulophids, emerged from mines formed by 4th- and 5th-instar leafminer larvae. The species were primary, secondary, or facultative secondary parasitoids. Five were new records. The braconid Pholetesor ornigis (Weed) was the most abundant in the first and third leafminer generations, and the eulophid Sympiesis marylandensis Girault was the most abundant in the second generation. Ratios of parasitoids to Phyllonorycter spp. were generally higher in samples from unsprayed trees than in those from sprayed trees. Major parasitoids usually emerged 1 to 4 wk before their larval hosts became plentiful. Sweep samples indicated relatively high abundance of one or both major parasitoids during the first and second leafminer generations. Monitoring of parasitoids and the judicious use of insecticides may have a critical role in pest management programs utilizing native parasitoids of leafminers.

The Body Temperature of Tenebrionid Beetles in the Namib Desert of Southern Africa

1971 ◽  
Vol 55 (1) ◽  
pp. 253-272
Author(s):  
E. B. EDNEY
Keyword(s):  
Heat Balance ◽  
Muscular Activity ◽  
Selective Advantage ◽  
Short Wave ◽  
The Body ◽  
Wave Radiation ◽  
Consistent Difference ◽  
Angle Of Incidence ◽  
Lethal Temperatures ◽  
The Difference

1. In direct sunshine the abdomen of living Onymacris brincki, which is covered by white elytra, was 3-4 °C cooler than its thorax, while in the same conditions the abdomen and thorax of O. rugatipemtis, which is an entirely black beetle, had the same temperature. Since similar effects were observed in dead beetles, the warmer thorax was not due to muscular activity. When the white elytra of brincki were covered with carbon black, its abdominal temperature rose to equal that of rugatipenntis. Models, made of pieces of black and white elytra, showed similar effects. 2. The smaller species Stenocara eburnea (with white elytra) showed a smaller and less consistent temperature depression when compared with the similar-sized species S. depressa (which is black). Abdomens of O. rugatipennis, O. laeviceps and Physosterna cribripes (all large black beetles) were from 3-5 °C wanner than O. brincki, but showed no consistent difference among themselves. 3. When O. rugatipennis was oriented head-on to the sun in its natural environment its thorax was about 4 °C cooler than when its long axis was normal to the sun's rays. Beetles exposed to sunshine were 12-15 °C warmer than they were in the shade. When transferred from one to the other, the greater part of temperature equilibration occurred in about 2 min and equilibration was complete in about 4 min. 4. Observation suggested that beetles thermoregulate by moving between sunshine and shade. Measurements showed that a beetle exposed to alternating periods of 10 sec in sunshine and 30 sec in shade reached a steady temperature of about 33 °C, while the reverse conditions (10 sec in the shade and 30 sec in sunshine) led to a temperature of about 38 °C. In continuous alternations thoracic temperatures remained constant within about 1 °C. 5. Laboratory experiments in which the angle of incidence of the sun's rays was varied through 180° confirmed the field results and showed that white elytra lower the abdominal temperature of living and dead beetles. 6. Upper lethal temperatures for 30 min in saturated air varied from 50 °C for the desert tenebrionid Onymacris plana to 42.5 °C for the mesic species Trigonopus capicola. In general, upper lethal temperatures correlated well with habitat and habit. 7. Making certain assumptions, analysis of the heat balance of beetles during one exposure in sunshine suggests that the difference between the white elytra of brincki and the black ones of rugatipennis as regards the amount of short-wave radiation reflected is 0.227 cal cm-2 min-1, and further, that the reflectivities of the two surfaces are 79% and 38% respectively. 8. The selective advantage of white elytra probably has little to do with heat balance; the vivid contrast between white and black suggests that the pattern may be aposematic.

scholarly journals Hymenopterous parasites associated with Phyllonorycter blancardella [Lepidoptera: Gracillariidae] in Nova Scotia and Quebec

2005 ◽  
Vol 82 (2) ◽  
pp. 65-71 ◽  
Author(s):  
S.D. Bishop ◽  
R.F. Smith ◽  
C. Vincent ◽  
H. Goulet ◽  
J. Huber ◽  
...  
Keyword(s):  
Nova Scotia ◽  
North America ◽  
Relative Abundance ◽  
Parasite Species ◽  
New Records ◽  
Apple Orchards ◽  
Phyllonorycter Blancardella ◽  
Abundance And Diversity ◽  
Prevalent Species ◽  
Pholetesor Ornigis

Mined leaves were collected in commercial and unsprayed (no insecticides) apple orchards of Quebec and Nova Scotia to determine the relative abundance and diversity of parasites of the spotted tentiform leafminer, Phyllonorycter blancardella [Lepidoptera: Gracillariidae]. In Quebec, 29 species of leafminer parasites were recovered, belonging to 7 families: Aphelinidae, Braconidae, Chalcidae, Eulophidae, Ichneumonidae, Pteromalidae and Scelionidae. The most prevalent species were Pholetesor ornigis (67%), Sympiesis marylandensis (11%), S. serviceicornis (7%), Pnigalio maculipes (1.5%), Tetrasticus spp. (1.2%), while all other species accounted for < 1.0%. Pholetesor pedias, a braconid released in 1983 at Frelighsburg, Quebec, was not found in the 1984 and 1985 surveys. In Nova Scotia, 19 parasite species were recovered, belonging to 5 families : Braconidae, Encyrtidae, Eulophidae, Ichneumonidae and Pteromalidae. The most prevalent species were: Pholetesor ornigis (52%), Pnigalio maculipes (14%), Sympiesis serviceicornis (12%), S. marylandensis (9.5%), Sympiesis spp. (5%), Horismenus fraternus (1.8%), Paraleurocerus sp. (1.3%), Stictopisthus flaviceps (1.1%), while all other species accounted for < 1%. Seven and five species of hyperparasites were recovered in Nova Scotia and Quebec, respectively. New records for North America for the spotted tentiform leafminer as a host are : Sticopisthus bilineatus, S. flaviceps, Euderis sp., Pnigalio epilobii, P. pallipes and Paraleurocerus bicoloripes.

RESISTANCE OF THE SPOTTED TENTIFORM LEAFMINER, PHYLLONORYCTER BLANCARDELLA (LEPIDOPTERA: GRACILLARIIDAE), TO ORGANOPHOSPHOROUS INSECTICIDES IN SOUTHERN ONTARIO

1980 ◽  
Vol 112 (5) ◽  
pp. 469-474 ◽  
Author(s):  
D. J. Pree ◽  
E. A. C. Hagley ◽  
C. M. Simpson ◽  
A. Hikichi
Keyword(s):  
Synthetic Pyrethroid ◽  
Cross Resistance ◽  
Pyrethroid Insecticides ◽  
Southern Ontario ◽  
Phyllonorycter Blancardella ◽  
Organophosphorous Insecticides

AbstractPopulations of the spotted tentiform leafminer, Phyllonorycter blancardella (Fabr.), from sprayed orchards across southern Ontario were found highly resistant (about 160-fold at LC50) to azinphosmethyl. Cross resistance to phosmet and partial cross resistance to diazinon were also indicated. All populations were highly susceptible to several synthetic pyrethroid insecticides. Resistant populations were controlled with pyrethroid insecticides applied when eggs were first found or by methomyl applied at about 50% hatch.

EFFECTS OF PYRETHROID INSECTICIDES ON EGGS AND LARVAE OF RESISTANT AND SUSCEPTIBLE POPULATIONS OF SPOTTED TENTIFORM LEAFMINER

1986 ◽  
Vol 118 (11) ◽  
pp. 1123-1130 ◽  
Author(s):  
D.B. Marshall ◽  
D.J. Pree
Keyword(s):  
Pyrethroid Insecticides ◽  
Larval Stages ◽  
Resistant Strains ◽  
Phyllonorycter Blancardella ◽  
Low Levels ◽  
Susceptible Populations ◽  
Eggs And Larvae

AbstractResistance to pyrethroid insecticides, identified previously in adults of Phyllonorycter blancardella (Fabr.), was shown to extend to both egg and larval stages. Eggs of both resistant and susceptible strains were more susceptible than larvae to various pyrethroid insecticides. Eggs treated 0–2 days post oviposition were more susceptible than 4- to 6-day-old eggs and/or larvae for both strains. Older larvae, especially from resistant strains, were less susceptible than early instars. For eggs and 1st-instar larvae, differences between resistant and susceptible strains were largely overcome by treatment with higher concentrations of permethrin. In the field, low levels of resistance were overcome by applications of permethrin at 212.5 g AI/ha diluted in 3370 L water/ha timed for first hatch of eggs.

scholarly journals Does group assessment impact BME attainment?

2016 ◽  
Author(s):  
Natasha Hill ◽  
James Denholm Price ◽  
Nigel Atkins ◽  
Luis Tojal Dourado ◽  
Owuraku Nimoh ◽  
...  
Keyword(s):  
Student Satisfaction ◽  
Group Work ◽  
Consistent Difference ◽  
Group Assessment ◽  
League Tables ◽  
Attainment Gap ◽  
The Difference ◽  
Assessment Of Student Learning ◽  
Mixed Groups ◽  
Minority Ethnic

Assessment of student learning is fundamental in Higher Education (HE) reflecting academic standards and impacting on student satisfaction, position in league tables and graduate employment.  Nonetheless, there is a BME (Black and Minority Ethnic) attainment gap, the difference in the proportion of BME and White students who attain a first class or 2.1 honours degree (even when controlled for prior attainment and entry profile), which is persistent across the HE sector. As assessment strategies play an essential role in determining degree attainment, we have reviewed the role of group assessment and whether this form of assessment specifically impacts on the BME attainment gap. Overall, this study provided evidence that assessed group work does not adversely impact BME students. In addition, the performance in BME/non-BME/mixed groups did not suggest any consistent difference, suggesting that the demographic composition of groups does not affect BME performance. Therefore, group work would appear to be an inclusive form of assessment that does not appear to lead or contribute to exacerbating the BME attainment gap.Keywords: Group assessment; attainment; Black and Minority Ethnic

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