CONTROLLING INSECT ENEMIES OF THE ALFALFA LEAF-CUTTER BEE, MEGACHILE ROTUNDATA

1968 ◽  
Vol 100 (7) ◽  
pp. 781-784 ◽  
Author(s):  
G. A. Hobbs

AbstractThe debris-feeding insects Trogoderma glabrum (Hbst.), Tribolium madens Charp., Cryptolestes ferrugineus (Steph.), and Vitula edmandsae Pack, were controlled by cleaning out die nests of Megachile rotundata L. annually and screening off the debris, and by discarding the cells of M. rotundata after emergence was complete. The chalcidoid parasites Monodontomerus obscurus Westw. and Pteromalus venustus Wlkr. and the depredators Coelioxys spp., were removed by light-trapping them in the incubators in which M. rotundata was being hatched. The removal was made possible because the incubation period of each of the indigenous enemies was considerably shorter than that of their exotic host.

1969 ◽  
Vol 101 (4) ◽  
pp. 418-422 ◽  
Author(s):  
Oswald Peck

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.


Genome ◽  
1996 ◽  
Vol 39 (4) ◽  
pp. 655-663 ◽  
Author(s):  
Rui Lu ◽  
Gerald H. Rank

RAPD analyses were performed on five geographically isolated populations of Megachile rotundata. We used haploid males of the alfalfa leaf-cutting bee, M. rotundata, to overcome the limitation of the dominance of RAPD markers in the determination of population genetic parameters. Sixteen primers gave rise to 130 polymorphic and 31 monomorphic bands. The unbiased estimators calculated in this study include within- and between-population heterozygosity, nucleotide divergence, and genetic distance. The genetic diversity (H = 0.32–0.35) was found to be about 10 times that of previous estimates (H = 0.033) based on allozyme data. Contrary to the data obtained at the protein level, our results suggest that Hymenoptera do not have a lower level of genetic variability at the DNA level compared with other insect species. Regardless of the different assumptions underlying the calculation of heterozygosity, divergence, and genetic distance, all five populations showed a parallel interrelationship for the three parameters. We conclude that RAPD markers are a convenient tool to estimate population genetic variation in haploid M. rotundata and that with an adequate sample size the technique is applicable to the evaluation of divergence in diploid populations. Key words : Megachile rotundata, RAPD, heterozygosity, genetic distance, nucleotide divergence.


1988 ◽  
Vol 66 (12) ◽  
pp. 2541-2560 ◽  
Author(s):  
John Bissett

Cultures and herbarium collections of the previously described species of Ascosphaera were studied. Additional observations are reported on Ascosphaera strains associated with the alfalfa leaf-cutting bee, Megachile rotundata (Fab.). Three new species of Ascosphaera are described, all occurring in brood cells of the alfalfa leaf-cutting bee. Ascosphaera larvis sp.nov., with short, ellipsoidal ascospores, was frequently associated with a chalkbrood-like disease in early-instar larvae. Ascosphaera pollenicola sp.nov., a homothallic species with subcylindric ascospores, most often occurred on pollen provisions in brood cells. Ascosphaera variegata sp.nov., with conspicuously mottled ascomatal walls, was isolated from pollen and also from larvae that had died from undetermined causes. Descriptions and an identification key are provided for the 11 species of Ascosphaera currently recognized.


2006 ◽  
Vol 36 (18) ◽  
pp. 59
Author(s):  
ERIK GOLDMAN
Keyword(s):  

1973 ◽  
Vol 29 (01) ◽  
pp. 183-189
Author(s):  
C. A Praga ◽  
E. M Pogliani

SummaryTemperature represents a very important variable in ADP-induced platelet aggregation.When low doses of ADP ( < 1 (μM) are used to induce platelet aggregation, the length of the incubation period of PRP in the cuvette holder of the aggregometer, thermostatted at 37° C, is very critical. Samples of the same PRP previously kept at room temperature, were incubated for increasing periods of time in the cuvette of the aggregometer before adding ADP, and a significant decrease of aggregation, proportional to the length of incubation, was observed. Stirring of the PRP during the incubation period made these changes more evident.To measure the exact temperature of the PRP during incubation in the aggre- gometer, a thermocouple device was used. While the temperature of the cuvette holder was stable at 37° C, the PRP temperature itself increased exponentially, taking about ten minutes from the beginning of the incubation to reach the value of 37° C. The above results have a practical significance in the reproducibility of the platelet aggregation test in vitro and acquire particular value when the effect of inhibitors of ADP induced platelet aggregation is studied.Experiments carried out with three anti-aggregating agents (acetyl salicyclic acid, dipyridamole and metergoline) have shown that the incubation conditions which influence both the effect of the drugs on platelets and the ADP breakdown in plasma must be strictly controlled.


1975 ◽  
Vol 34 (03) ◽  
pp. 780-794 ◽  
Author(s):  
Dianne M Kenney ◽  
Francis C Chao ◽  
James L Tullis ◽  
Gail S Conneely

SummaryThe uptake and binding of antimitotic alkaloid colchicine has been demonstrated in washed preparations of human platelets. A silicone oil technique was adapted so that both uptake and binding of 14C-colchicine were examined in the same platelet preparations. The time dependence and amount of colchicine taken up and bound by different platelet preparations during a 90 to 120 min incubation period were highly reproducible. Both colchicine uptake and binding by intact platelets, and colchicine binding by preparations of lysed platelets were specific and temperature dependent. Colchicine uptake was slowly reversible. Magnesium and GTP enhanced colchicine binding by lysed platelet preparations but calcium decreased binding.Exposure of platelets to either cold (4° C) or to thrombin, which disrupt platelet microtubules, produced significant increases in colchicine uptake and binding. The thrombin effect was maximal at 37° C and resulted in a greater increase in uptake and binding than that produced by either cold treatment alone or, by cold treatment followed by incubation with thrombin at 37° C. The amount of increase in uptake and binding produced by thrombin was independent of both thrombin (1–5 Units/109 platelets) and colchicine concentrations (1–50 × 10−6M).It is postulated that thrombin may initiate the formation, or make available, colchicine binding sites (microtubule subunits) within platelets.


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