GRAIN APHIDS IN NEW BRUNSWICK: II. COMPARATIVE DEVELOPMENT IN THE GREENHOUSE OF THREE APHID SPECIES ON FOUR KINDS OF GRASSES

1964 ◽  
Vol 42 (5) ◽  
pp. 741-744 ◽  
Author(s):  
Jean B. Adams ◽  
Margaret E. Drew

The development of three grain-infesting aphids, Rhopalosiphum padi (L.), Macrosiphum avenae (Fab.), and Rhopalosiphum maidis (Fitch), was studied on four members of the Gramineae: Avena, Triticum, Hordeum, and Poa, in the greenhouse. Wingless R. padi developed most rapidly irrespective of host. In general, winged forms took longer to mature than wingless forms of all species except R. maidis on Avena. Hordeum was the preferred host of all species and on this host R. padi produced per adult 59 nymphs, R. maidis 49, and M. avenae 37. The mean length of life of all species on all hosts was 28.8 days but wide variations occurred on different hosts. Neither R. padi nor R. maidis accepted Poa, nor did R. maidis survive on Triticum under our conditions.

1976 ◽  
Vol 108 (10) ◽  
pp. 1069-1078 ◽  
Author(s):  
Jean B. Adams ◽  
M. E. Drew ◽  
M. E. MacGillivray

AbstractGauze covers placed over the entrance of one air intake louver (1.52 m × 1.52 m, ht. 11.85 m, air passage 3055.8 cu.m/min) on the penthouse of the Research Station, from May until December, during a 3-year period, trapped more than 150 aphid species. In addition a considerable amount of intercepted aphid material was identified to genus only. A total of 31,482 specimens were trapped over the period.Five species, Rhopalosiphum maidis (Fitch), Rhopalosiphum padi (Linnaeus), Mindarus abietinus Koch, Alhis craccae Linnaeus, and Capitophorus eleagni (del Guercio), predominated in all years. In 1967 and 1968 more than 100 specimens each of Pterocallis alnifoliae (Fitch), Tinocallis ulmifolii Monell, Myzocallis occultus Richards, Prociphilus americanus (Walker), Capitophorus hippophaes (Walker), Hayhurstia atriplicis (Linnaeus), Thuleaphis rumexicolens (Patch), and Myzus persicae (Sulzer) were trapped each year.Once potential development temperatures were reached there was little correlation between mean temperatures and aphid numbers up until frost.The earliest interception was 6 May; general dispersal was under way by 6 June and continued until late November, despite preceding October frost.


1964 ◽  
Vol 42 (5) ◽  
pp. 735-740 ◽  
Author(s):  
Jean B. Adams ◽  
Margaret E. Drew

Commonly three species of aphids infest oats in New Brunswick, Canada. These aphids are Rhopalosiphum padi (L.), Macrosiphum avenae (Fab.), and Rhopalosiphum maidis (Fitch), named in the order of their abundance. Over a 5-year period (1959–1963 incl.) infestations varied from peaks of less than 1 aphid to 250 aphids per tiller. The aphids infested the crop for approximately 7 weeks, from the time the plants were 3 in. high until the panicles had emerged. When the panicle stage was reached (normally in the fourth or fifth week of the infestation), a winged generation of aphids developed and dispersed from the oats, resulting in an abrupt decline in the population.


1961 ◽  
Vol 39 (4) ◽  
pp. 495-503 ◽  
Author(s):  
G. B. Orlob

The occurrence, distribution, and biology of various cereal and grass aphids were noted in New Brunswick during 1960. Because of the similarity of Rhopalosiphum padi (L.) overwintering on Pruneae, and R. fitchii (Sanderson) hibernating on Pomeae, summer forms of these aphids are referred to as the R. padi-fitchii complex. An aphid from Phleum pratense L., very similar and closely related to Schizaphis graminum (Rondani), is described as S. graminum phlei ssp. n. Circumstantial evidence indicates that early spring migrants of Rhopalosiphum maidis (Fitch) and Macrosiphum avenue (Fabricius) did not originate in the province.


2018 ◽  
Author(s):  
Natalia Banasik ◽  
Dariusz Jemielniak ◽  
Wojciech P?dzich

BACKGROUND There have been mixed results of the studies checking whether prayers do actually extend the life duration of the people prayed for. Most studies on the topic included a small number of prayers and most of them focused on people already struggling with a medical condition. Intercessory prayer’s influence on health is of scholarly interest, yet it is unclear if its effect may be dependent on the number of prayers for a named individual received per annum. OBJECTIVE We sought to examine if there is a noticeable increased longevity effect of intercessory prayer for a named individual’s well-being, if he receives a very high number of prayers per annum for an extended period. METHODS We retrieved and conducted a statistical analysis of the data about the length of life for 857 Roman Catholic bishops, 500 Catholic priests, and 3038 male academics from the US, France, Italy, Poland, Brazil, and Mexico. We obtained information for these individuals who died between 1988 and 2018 from Wikidata, and conducted an observational cohort study. Bishops were chosen for the study, as they receive millions of individual prayers for well being, according to conservative estimates. RESULTS There was a main effect for occupation F(2, 4391) = 4.07, p = .017, ηp 2 = .002, with pairwise comparisons indicating significant differences between the mean life duration of bishops (M=30489) and of priests (M=29894), but none between the academic teachers (M=30147) and either of the other groups. A comparison analysis between bishops from the largest and the smallest dioceses showed no significant difference t(67.31)=1.61, p = .11. Our main outcome measure is covariance of the mean length of life in each of the categories: bishops, priests, academic teachers, controlled for nationality. CONCLUSIONS The first analysis proved that bishops live longer than priests, but due to a marginal effect size this result should be treated with caution. No difference was found between the mean length of life of bishops from the largest and the smallest dioceses. We found no difference between bishops and male academics. These results show that the impact of intercessory prayers on longevity is not observable.


BMJ ◽  
1896 ◽  
Vol 2 (1867) ◽  
pp. 1045-1045
Keyword(s):  
The Mean ◽  

Plant Disease ◽  
2007 ◽  
Vol 91 (10) ◽  
pp. 1305-1309 ◽  
Author(s):  
Khalil I. Al-Mughrabi ◽  
Rick D. Peters ◽  
H. W. (Bud) Platt ◽  
Gilles Moreau ◽  
Appanna Vikram ◽  
...  

The efficacy of metalaxyl-m (Ridomil Gold 480EC) and phosphite (Phostrol) applied at planting in-furrow against pink rot (Phytophthora erythroseptica) of potato (Solanum tuberosum) ‘Shepody’ and ‘Russet Burbank’ was evaluated in field trials conducted in 2005 and 2006 in Florenceville, New Brunswick, Canada. Inoculum made from a metalaxyl-m-sensitive isolate of P. erythroseptica from New Brunswick was applied either in-furrow as a vermiculite slurry at planting or as a zoospore drench in soils adjacent to potato plants in late August. After harvest, the number and weight of tubers showing pink rot symptoms were assessed and expressed as percentages of the total tuber number and total weight of tubers. Metalaxyl-m applied in-furrow was significantly more effective against pink rot than phosphite. The mean percentage of diseased tubers as a percentage of total tuber weight was 1.5% (2005) and 1.2% (2006) for metalaxyl-m-treated plots and 9.6% (2005) and 2.8% (2006) for phosphite-treated plots, a percentage similar to that obtained in inoculated control plots with no fungicide treatment. The mean percentage of diseased tubers expressed as a percentage of the total number of tubers was 1.7% (2005) and 1.3% (2006) for metalaxyl-m-treated plots and 10.1% (2005) and 3.1% (2006) for phosphite-treated plots. Disease incidence was significantly higher using the late-season inoculation technique (respective means in 2005 and 2006 were 9.9 and 3.8% diseased tubers, by weight, and 10.6 and 3.9%, by number) than with the in-furrow inoculation method (respective means in 2005 and 2006 were 3.3 and 0.7% by weight, and 3.7 and 1.3%, by number). The potato cv. Shepody was significantly more susceptible to pink rot (9.9 and 3.3% diseased tubers, by weight, in 2005 and 2006, respectively, and 10.6 and 3.9%, by number) than Russet Burbank (respective means in 2005 and 2006 were 3.4,% and 1.2%, by weight, and 3.7,% and 1.2%, by number). Our findings indicate that metalaxyl applied in-furrow at planting is a viable option for control of pink rot caused by metalaxyl-sensitive strains of P. erythroseptica, whereas phosphite was ineffective.


1972 ◽  
Vol 104 (8) ◽  
pp. 1197-1207 ◽  
Author(s):  
R. F. Morris

AbstractThe number of predators inhabiting nests of Hyphantria cunea Drury was recorded annually for 13 years in four areas in New Brunswick and two areas on the coast of Nova Scotia. The most common groups were the pentatomids and spiders, which sometimes reproduced within the nests, but the mean number per nest was low in relation to the number of H. cunea larvae in the colonies. The rate of predation on fifth-instar larvae was low. Small or timid predators appeared to prey largely on moribund larvae or small saprophagans during the principal defoliating instars of H. cunea.No relationship could be detected between the number of larvae reaching the fifth instar and the number of predators in the colony; nor could any functional or numerical response of the predators to either the initial number of larvae per colony or the population density of colonies be found. It is concluded that the influence of the nest-inhabiting predators is small and relatively stable, and may be treated as a constant in the development of models to explain the population dynamics of H. cunea.H. cunea is a pest in parts of Europe and Asia, where it has been accidentally introduced from North America. The introduction to other continents of the North American predator, Podisus maculiventiis (Say), is discussed briefly.


2007 ◽  
Vol 139 (6) ◽  
pp. 850-863 ◽  
Author(s):  
Samuel M. Migui ◽  
Robert J. Lamb

AbstractThe susceptibilities of genetically diverse Canadian spring wheats, Triticum aestivum L. and Triticum durum Desf., to three aphid species, Rhopalosiphum padi (L.), Sitobion avenae (Fabricius), and Schizaphis graminum (Rondani), were investigated. Trophic interactions measured as changes in biomass of aphids and wheat plants were used to quantify levels of resistance, components of resistance, and impact of aphids on yield. Plants in field cages were infested with small numbers of aphids for 21 days at heading. These plants were usually more suitable for the development of S. avenae and S. graminum than of R. padi. Partial resistance, measured as seed production by infested plants as a proportion of that by a control, varied from 11% to 59% for different aphid species and wheat classes when all wheat plants were infested at the same stage. Cultivars within wheat classes responded similarly to each of the aphid species. None of the wheat cultivars showed agriculturally effective levels of antibiosis. The specific impact of each aphid species and wheat class varied from 5 to 15 mg of plant biomass lost for each milligram of biomass gained by the aphids. Canadian Western Red Spring wheat had a lower specific impact and therefore was more tolerant to aphids than the other two classes, but not tolerant enough to avoid economic damage at the aphid densities observed. Plants did not compensate for feeding damage after aphid feeding ceased, based on the higher specific impacts observed for mature plants than for plants that were heading. The interactions between aphids and plants show that current economic thresholds probably underestimate the damage caused by cereal aphids to Canadian spring wheat.


Insects ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 54 ◽  
Author(s):  
Ibtissem Ben Fekih ◽  
Annette Bruun Jensen ◽  
Sonia Boukhris-Bouhachem ◽  
Gabor Pozsgai ◽  
Salah Rezgui ◽  
...  

Pandora neoaphidis and Entomophthora planchoniana (phylum Entomophthoromycota) are important fungal pathogens on cereal aphids, Sitobion avenae and Rhopalosiphum padi. Here, we evaluated and compared for the first time the virulence of these two fungi, both produced in S. avenae cadavers, against the two aphid species subjected to the same exposure. Two laboratory bioassays were carried out using a method imitating entomophthoralean transmission in the field. Healthy colonies of the two aphid species were exposed to the same conidial shower of P. neoaphidis or E. planchoniana, in both cases from a cadaver of S. avenae. The experiments were performed under LD 18:6 h at 21 °C and a successful transmission was monitored for a period of nine days after initial exposure. Susceptibility of both S. avenae and R. padi to fungal infection showed a sigmoid trend. The fitted nonlinear model showed that the conspecific host, S. avenae, was more susceptible to E. planchoniana infection than the heterospecific host R. padi, was. In the case of P. neoaphidis, LT50 for S. avenae was 5.0 days compared to 5.9 days for R. padi. For E. planchoniana, the LT50 for S. avenae was 4.9 days, while the measured infection level in R. padi was always below 50 percent. Our results suggest that transmission from conspecific aphid host to heterospecific aphid host can occur in the field, but with expected highest transmission success to the conspecific host.


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