OCCURRENCE OF CHALKBROOD CAUSED BY ASCOSPHAERA AGGREGATA SKOU IN A NATIVE LEAFCUTTING BEE, MEGACHILE RELATIVA CRESSON (HYMENOPTERA: MEGACHILIDAE), IN SASKATCHEWAN

1990 ◽  
Vol 122 (6) ◽  
pp. 1269-1270 ◽  
Author(s):  
D.W. Goerzen ◽  
M.A. Erlandson ◽  
J. Bissett
Keyword(s):  
United States ◽  
Megachile Rotundata ◽  
Southern Alberta ◽  
Low Levels

The alfalfa leafcutting bee, Megachile rotundata (Fab.), is an important domesticated pollinator of alfalfa grown for seed in Canada. Chalkbrood, a disease caused by the fungus Ascosphaera aggregata Skou, has caused high mortalities in M. rotundata populations in the northwestern United States since 1972. Chalkbrood was found in Manitoba in 1982, Alberta in 1983, and Saskatchewan in 1984 (Richards 1985). Although subsequent surveys have indicated the presence of A. aggregata at high levels in some southern Alberta M. rotundata populations, the disease has been detected only sporadically and at low levels in Saskatchewan populations (Goerzen 1990).

OCCURRENCE OF CHALKBROOD CAUSED BY ASCOSPHAERA AGGREGATA SKOU IN A NATIVE LEAFCUTTING BEE, MEGACHILE PUGNATA SAY (HYMENOPTERA: MEGACHILIDAE), IN SASKATCHEWAN

1992 ◽  
Vol 124 (3) ◽  
pp. 557-558 ◽  
Author(s):  
D.W. Goerzen ◽  
L. Dumouchel ◽  
J. Bissett
Keyword(s):  
United States ◽  
Seed Production ◽  
Western Canada ◽  
Nest Material ◽  
Megachile Rotundata ◽  
Alfalfa Seed ◽  
Low Levels

The alfalfa leafcutting bee, Megachile rotundata (Fab.), is a domesticated pollinator important for alfalfa seed production in western Canada. Populations of M. rotundata are highly susceptible to chalkbrood, a disease caused by the fungus Ascosphaera aggregata Skou. The disease has caused high mortalities in M. rotundata populations in the northwestern United States since 1972. It was found in Manitoba in 1982, Alberta in 1983, and Saskatchewan in 1984 (Richards 1985). In subsequent surveys, A. aggregata has been detected only sporadically and at low levels of infection in Saskatchewan M. rotundata populations (Goerzen 1991). A previously reported observation of A. aggregata in the native leafcutting bee M. relativa Cresson (Goerzen et al. 1990) indicated that the disease is present in native leafcutting bee species which commonly immigrate into alfalfa leafcutting bee nest material.

scholarly journals Household COVID-19 risk and in-person schooling

Science ◽  
2021 ◽  
pp. eabh2939
Author(s):  
Justin Lessler ◽  
M. Kate Grabowski ◽  
Kyra H. Grantz ◽  
Elena Badillo-Goicoechea ◽  
C. Jessica E. Metcalf ◽  
...  
Keyword(s):  
United States ◽  
Online Survey ◽  
Positive Association ◽  
The United States ◽  
Mitigation Measures ◽  
Office Work ◽  
School Based ◽  
Increased Risk ◽  
Extra Curricular Activities ◽  
Low Levels

In-person schooling has proved contentious and difficult to study throughout the SARS-CoV-2 pandemic. Data from a massive online survey in the United States indicates an increased risk of COVID-19-related outcomes among respondents living with a child attending school in-person. School-based mitigation measures are associated with significant reductions in risk, particularly daily symptoms screens, teacher masking, and closure of extra-curricular activities. A positive association between in-person schooling and COVID-19 outcomes persists at low levels of mitigation, but when seven or more mitigation measures are reported, a significant relationship is no longer observed. Among teachers, working outside the home was associated with an increase in COVID-19-related outcomes, but this association is similar to other occupations (e.g., healthcare, office work). While in-person schooling is associated with household COVID-19 risk, this risk can likely be controlled with properly implemented school-based mitigation measures.

The United States Congress and Africanist Scholars

1991 ◽  
Vol 19 (2) ◽  
pp. 4-13
Author(s):  
David S. Wiley
Keyword(s):  
United States ◽  
Foreign Policy ◽  
The United States ◽  
African Studies ◽  
United States Congress ◽  
The Poor ◽  
Low Levels ◽  
The U.S

Linking scholars to the Congress is difficult primarily because of the weakness of Congressional interest in Africa, but also due to the low levels of interest among academics in both Congress and its Africa foreign policy and the poor resources of African studies in the U.S. to build a foundation of knowledge useful to the Congress.

Identifying Current Driver Rehabilitation Practices for Clients With Physical Impairments

2021 ◽  
Vol 75 (Supplement_2) ◽  
pp. 7512515346p1-7512515346p1
Author(s):  
W. Ben Mortenson ◽  
Brittany Langereis ◽  
Sarah Semeniuk ◽  
Lisa Kristalovich
Keyword(s):  
United States ◽  
Clinical Guidelines ◽  
The United States ◽  
Physical Impairments ◽  
Levels Of Evidence ◽  
Low Levels ◽  
Primary Author

Abstract Date Presented Accepted for AOTA INSPIRE 2021 but unable to be presented due to online event limitations. Currently, there is a lack of clinical guidelines to support clinicians working in driver rehabilitation. This study aimed to identify intervention practices and factors that influence driver rehabilitation recommendations by surveying driver rehabilitation specialists practicing across the United States and Canada. Results revealed both consistencies and inconsistencies in practice, which may be related to jurisdictional differences and relatively low levels of evidence in this area. Primary Author and Speaker: W. Ben Mortenson Contributing Authors: Brittany Langereis, Sarah Semeniuk, and Lisa Kristalovich

Is Social Anxiety Making Us Depressed?: A Social Evolutionary Hypothesis for Why SSRIs Work

2008 ◽  
Vol 10 (1) ◽  
pp. 16-30 ◽  
Author(s):  
Laura K. Kerr
Keyword(s):  
Mental Health ◽  
United States ◽  
Selective Serotonin Reuptake Inhibitors ◽  
Alternative Hypothesis ◽  
The United States ◽  
Global Competition ◽  
Low Levels ◽  
Chemical Imbalance ◽  
Developed Nations ◽  
Developed World

In the developed world, the use of selective serotonin reuptake inhibitors (SSRIs) has skyrocketed since 1988, when Prozac was first released in the United States. Biomedical psychiatry’s explanation for their success is an unsubstantiated hypothesis that claims SSRIs treat a chemical imbalance in people who suffer from low levels of the neurotransmitter serotonin. Using social evolutionary theory, this article provides an alternative hypothesis for why SSRIs work for some people. SSRIs’ success is attributed to their capacity to adapt people to the increased status anxiety occurring in developed nations grappling with the effects of unprecedented global competition. Biomedical psychiatry is depicted as adjusting patients to prevailing social norms rather than contributing to mental health.

scholarly journals Tilletia walkeri on Annual Ryegrass in Wheat Fields in the Southeastern United States

Plant Disease ◽  
1999 ◽  
Vol 83 (7) ◽  
pp. 685-689 ◽  
Author(s):  
Barry M. Cunfer ◽  
Lisa A. Castlebury
Keyword(s):  
United States ◽  
Lolium Multiflorum ◽  
Southeastern United States ◽  
Karnal Bunt ◽  
Annual Ryegrass ◽  
Wheat Seed ◽  
Tilletia Indica ◽  
Wheat Field ◽  
South Central ◽  
Low Levels

Surveys for Tilletia walkeri on annual ryegrass (Lolium multiflorum) were conducted during 1997 and 1998 in the southeastern United States, where suspect teliospores of the Karnal bunt fungus, Tilletia indica, were found in USDA-APHIS surveys of wheat (Triticum aestivum) seed in 1996. T. walkeri is morphologically similar to T. indica. Annual ryegrass is a common weed in wheat fields in the southeastern United States. Between April and June 1997, ryegrass seed samples were collected from 190 fields of wheat in 47 counties in Georgia and from 26 fields in 17 counties in Alabama and south-central Tennessee. In 1998, 70 samples were collected from 40 counties in the same regions of the three states. The teliospores from these samples were 23 to 45 μm in diameter (average about 33 μm) and ranged from light brown to dark reddish brown. They had coarse, widely spaced cerebriform ridges on the surface and were surrounded by a gelatinous sheath. The ryegrass bunt was identified as the recently described species T. walkeri, occurring on ryegrass seed from Australia and Oregon. In 1997, teliospores of T. walkeri were found in 13 samples from eight counties in central Georgia and from one field in Tennessee. In 1998, more teliospores and bunted seeds were found, possibly due to frequent rain in the region throughout the flowering period for ryegrass. Teliospores were found in 26/70 of the samples, and among these, only a small number of bunted seed were found in 12 of 13/70 samples. In one wheat field in Morgan County, Georgia, about 50% of the ryegrass seed collected was partially bunted, and a small percentage was completely bunted. Fields with teliospores were widely distributed and generally matched the locations where teliospores were found in APHIS wheat seed surveys in 1996 to 1998. T. walkeri occurs at very low levels on ryegrass in the Southeast and is the source of teliospores, initially identified as those of T. indica, associated with wheat seed in APHIS surveys. No bunted wheat seeds or teliospores of T. indica were found in the survey.

EFFECT OF ENVIRONMENT AND EQUIPMENT ON PRODUCTIVITY OF ALFALFA LEAFCUTTER BEES (HYMENOPTERA: MEGACHILIDAE) IN SOUTHERN ALBERTA, CANADA

1996 ◽  
Vol 128 (1) ◽  
pp. 47-56 ◽  
Author(s):  
K.W. Richards
Keyword(s):  
Environmental Variables ◽  
Total Cell ◽  
Significant Positive Effect ◽  
Megachile Rotundata ◽  
Southern Alberta ◽  
Temperature Heat ◽  
Leafcutter Bee ◽  
Nesting Material ◽  
Higher Temperature ◽  
Positive Effect

AbstractFour indicators of productivity and quality for the alfalfa leafcutter bee, Megachile rotundata (Fab.), were examined over a 3-year period and the influence of different shelter designs, nesting materials, and 34 environmental variables evaluated. A higher percentage of cocoons per total cells was produced in polystyrene nesting material than in pinewood nesting material. Both nesting materials had similar percentages of tunnels capped or containing cells and total numbers of cells per hive. Shelters with conspicuous orientation patterns or silhouettes had more tunnels capped per hive, tunnels with cells, and greater total cell production per hive than did other shelter designs. The time of maximum bee production varied greatly among the 3 years. Many environmental variables, especially those associated with higher temperature, heat units, and mean actual temperature, had a significant positive effect on bee productivity and cell quality. The information contained in this study may help delineate those climatic areas where this valuable alfalfa pollinator can be most effective, and may assist beekeepers in making management decisions that will improve their operations.

CHALCIDOID (HYMENOPTERA) PARASITES OF THE ALFALFA LEAF-CUTTER BEE, MEGACHILE ROTUNDATA, IN CANADA

1969 ◽  
Vol 101 (4) ◽  
pp. 418-422 ◽  
Author(s):  
Oswald Peck
Keyword(s):  
Megachile Rotundata ◽  
Parasitic Species ◽  
Water Traps ◽  
Southern Alberta ◽  
Alfalfa Leaf ◽  
Fourth Species

AbstractMegachile rotundata (F.) is a domesticated bee used to pollinate alfalfa in southern Alberta. There it may have four species of parasites, all chalcidoids. These parasites are removable by water traps before the hives are set in the field. Three of these parasites, Monodontomerus obscurus Westw., Dibrachys maculipennis Sz., and Pteromalus venustus Wlkr,, are European in origin. The first seems not to be established in Canada; the latter two have been reared from Canadian species of Megachile and thereby may prove a source of parasitism. The fourth species, Melittobia chalybii Ashm., is a widespread, nearctic, multivoltine species and is known as a laboratory pest of hymenopterous nests; it is likely to be the major parasite in rotundata nests. A key is given for the parasitic species.

Gall Aphids on Poplar in Alberta II. Periods of Emergence from Galls, Reproductive Capacities, and Predators of Aphids in Galls

1959 ◽  
Vol 91 (11) ◽  
pp. 680-685 ◽  
Author(s):  
A. M. Harper
Keyword(s):  
United States ◽  
Life Cycle ◽  
Economic Importance ◽  
Sugar Beets ◽  
Poplar Trees ◽  
Southern Alberta ◽  
Pemphigus Betae ◽  
Poplar Leaf

In southern Alberta there are several species of aphids that produce galls on poplar trees (Harper, 1959). These aphids are all in the subfamily Eriosomatinae and in the genera Pemphigus Hartig, Thecabius Koch, and Mordwilkoja Del. G. Two of the species are of economic importance, Pemphigus betae Doane, a pest of sugar beets in Alberta and parts of United States (Harper, 1957; Maxson, 1916; Parker, 1915), and Pemphigus populitransversus Riley, a serious pest of crucifers in Texas (Wene and White, 1953). Both species overwinter on poplar as eggs. In spring the fundatrix emerges from the egg and feeds on the poplar leaf, initiating a gall in which the winged fundatrigeniae are produced. During the summer the fundatrigeniae migrate to the secondary host where they produce the wingless alienicolae; in the fall these in turn produce the winged sexuparae, which migrate to the poplars where they produce the wingless sexuales. The female sexuales, after mating, deposit eggs on the poplars to complete the life cycle (Harper, 1957; Jones and Gillette, 1918; Parker, 1914).

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