COMPARISON OF TUMBLERS USED TO REMOVE DEBRIS FROM CELLS OF THE ALFALFA LEAFCUTTER BEE, MEGACHILE ROTUNDATA (HYMENOPTERA: MEGACHILIDAE)

1984 ◽  
Vol 116 (5) ◽  
pp. 719-723 ◽  
Author(s):  
K. W. Richards
Keyword(s):  
Megachile Rotundata ◽  
Initial Sample ◽  
Sample Weight ◽  
Leafcutter Bee ◽  
Initial Sample Weight

AbstractTumblers used to remove debris-feeding insects, predators of the leafcutter bee, excess leaf pieces, debris, and plant foliar molds from cells of the alfalfa leafcutter bee were compared. A hand-cranked tumbler removed significantly more material than did five motor-driven tumblers. It also removed more debris as the initial sample weight increased.

TOXICITY OF INSECTICIDES TO THE ALFALFA LEAFCUTTER BEE, MEGACHILE ROTUNDATA F. (HYMENOPTERA: MEGACHILIDAE), ESTABLISHED BY THREE EVALUATION METHODS

1988 ◽  
Vol 120 (4) ◽  
pp. 297-305 ◽  
Author(s):  
W. A. Charnetski
Keyword(s):  
Petri Dish ◽  
Evaluation Methods ◽  
Laboratory Evaluation ◽  
Evaluation Procedure ◽  
Megachile Rotundata ◽  
Field Cage ◽  
Male And Female ◽  
Significant Difference ◽  
Leafcutter Bee ◽  
Significant Mortality

AbstractThree methods—tube chambers (ventilated and unventilated), petri dish chambers, and field cages—were used to evaluate the toxicity of deltamethrin, trichlorfon, and methoxychlor deposits on alfalfa, Medicago sativa L., to 1- to 7-day-old alfalfa leafcutter bees, Megachile rotundata (F.), 24 and 48 h after exposure. In unventilated tube chambers, all three insecticides were significantly toxic to male bees after 24 and 48 h, but only deltamethrin and trichlorfon were significantly toxic to female bees after 24 h. In ventilated tube chambers, only deltamethrin was significantly toxic by contact and then only to male bees at 24 h. Significant vapor action was observed only for trichlorfon and only in unventilated tube chambers. By the petri dish method, only deltamethrin caused significant mortality to male and female bees. However, bee mortality increased significantly between 24 and 48 h. By the field cage method, there was no significant difference in mortality among treatments and controls within the 24- and 48-h evaluations. Bee mortality in the controls was much higher in the petri dish and field cage methods than in either of the two variations of the tube chamber method. The three evaluation methods are compared and the need for a standardized laboratory evaluation procedure is discussed.

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.

IMPACT OF DAMAGE BY THE DRIEDFRUIT MOTH, VITULA EDMANDSAE SERRATILINEELLA (LEPIDOPTERA: PYRALIDAE), A PEST OF THE ALFALFA LEAFCUTTER BEE, MEGACHILE ROTUNDATA (HYMENOPTERA: MEGACHILIDAE)

1983 ◽  
Vol 115 (12) ◽  
pp. 1549-1553 ◽  
Author(s):  
K. W. Richards
Keyword(s):  
Positive Relationship ◽  
Megachile Rotundata ◽  
Wood Material ◽  
Significant Positive Relationship ◽  
Leafcutter Bee ◽  
Lepidoptera Pyralidae ◽  
Nesting Material

AbstractLarvae of the driedfruit moth, Vitula edmandsae serratilineella Ragonot, enter uncapped tunnels in hives of the alfalfa leafcutter bee, Megachile rotundata F., and eat the pollen and nectar provisions of incomplete cells. Significantly more cocoons are destroyed in hives made of pine nesting material than in those made of polystyrene nesting material. However, significantly more tunnel walls are chewed into and through in the polystyrene than in the wood material. A significant positive relationship exists between the number of moth larvae per hive and the number of bee cells produced in that hive. After hives are removed from the field and placed in storage for the winter, most mature larvae leave the tunnels upon completion of feeding and aggregate in spaces between hives.

POSTDIAPAUSE DEVELOPMENT AND ADULT EMERGENCE OF PTEROMALUS VENUSTUS WALKER (HYMENOPTERA: PTEROMALIDAE) DURING ALFALFA LEAFCUTTER BEE INCUBATION

1987 ◽  
Vol 119 (5) ◽  
pp. 491-493 ◽  
Author(s):  
G.H. Whitfield ◽  
K.W. Richards
Keyword(s):  
Adult Emergence ◽  
The United States ◽  
Control Measures ◽  
Western Canada ◽  
Light Traps ◽  
Megachile Rotundata ◽  
Timing Control ◽  
Influence Of Temperature ◽  
Influence Of Temperature On ◽  
Leafcutter Bee

Pteromalus venustus Walker is the most common parasitoid associated with the alfalfa leafcutter bee, Megachile rotundata (F.), in western Canada (Richards 1984). Leafcutter beekeepers in Canada and the United States use several methods to control P. venustus during incubation of leafcutter bee larvae, including light traps (Hobbs 1973; Richards 1984), dipping the cells in an insecticide (Brindley 1976; Parker 1979), and placing dichlorvos resin strips in the incubator (Hill et al. 1984). Previously we described the influence of temperature on survival and rate of development of the egg, larval, and pupal stages of non-diapausing P. venustus (Whitfield and Richards 1985). Here we report on the influence of temperature on rate of postdiapause development in P. venustus during leafcutter bee incubation and consider the value of this information for timing control measures for this parasitoid.

NUMBER OF INSTARS OF LARVAE OF THE ALFALFA LEAFCUTTER BEE, MEGACHILE ROTUNDATA (F.) (HYMENOPTERA: MEGACHILIDAE)

1987 ◽  
Vol 119 (10) ◽  
pp. 859-865 ◽  
Author(s):  
G.H. Whitfield ◽  
K.W. Richards ◽  
T.M. Kveder
Keyword(s):  
Linear Regression ◽  
Frequency Distribution ◽  
Direct Observation ◽  
Field Studies ◽  
Accurate Method ◽  
Head Capsule ◽  
Physical Injury ◽  
Megachile Rotundata ◽  
Head Capsule Width ◽  
Leafcutter Bee

AbstractThe number of instars of larvae of the alfalfa leafcutter bee, Megachile rotundata (F.), was determined by direct observation, frequency distribution plots, and linear regression of head-capsule measurements. For all three methods, developmental polymorphism was observed; larvae were grouped according to the number of instars. The majority of larvae (77%) had four larval instars and the remainder had five. Mortality of bee larvae, apparently a result of physical injury during measurement of head-capsule width, was high but results were based on data for 259 individuals that completed development to the prepupal (= pharate pupa) stage. Direct observation of larval moults was found to be the only accurate method for determining instar designation but analysis of head-capsule width did describe the number of instars present in a population and provided estimates of head-capsule width for each instar. A morphological key for separation among four instars is presented as a practical alternative for instar determination in field studies.

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