SUMMER DIAPAUSE IN PHYLLONORYCTER BLANCARDELLA (FABR.) (LEPIDOPTERA: GRACILLARIIDAE) IN ONTARIO

1986 ◽  
Vol 118 (1) ◽  
pp. 17-28 ◽  
Author(s):  
J.E. Laing ◽  
J.M. Heraty ◽  
J.E. Corrigan

AbstractThe life stages of Phyllonorycter blancardella (Fabr.) were monitored in an orchard at Guelph, Ontario in 1981 and 1982 and the results showed discrepancies with the previous concept of a trivoltine species occurring throughout its range in eastern North America. Sleeve cages were used to monitor the development of the second, mid-summer generation of leaf miners in a low-maintenance orchard at Guelph in 1982 and 1984 and 2 commercial orchards at Simcoe, Ontario in 1984. The flight period of the first-generation adults occurred over approximately a 6-week period. From eggs laid early in the flight period, a large proportion of the larvae developed quickly and emerged to give a second-generation adult flight. As the flight period continued, there was an increase in the number of progeny whose development was delayed in the early instars. These larvae did not pupate until late fall and overwintered as pupae. Of the second-generation larvae, about 70–90% at Guelph and 35% at Simcoe had a delayed development (summer diapause) and formed a large proportion of the overwintering population.

2009 ◽  
Vol 2009 ◽  
pp. 1-5 ◽  
Author(s):  
Andrew K. Davis

Monarch butterflies are famous among insects for their unique migration in eastern North America to overwinter sites in Mexico and their bright orange wing color, which has an aposematic function. While capturing migrating monarchs in northeast Georgia, USA, I noticed that many appeared to have unusually deep orange wings. I initiated the current study to compare wing hues (obtained using image analysis of scanned wings) of migrants (captured in 2005 and 2008) to samples of breeding and overwintering monarchs. Consistent with initial observations, migrants had significantly lower orange hues (reflecting deeper, redder orange colors) than breeding and overwintering monarchs. There was also a difference in hue between sexes and a relationship with wing size, such that larger monarchs had deeper, redder hues. The reasons for the color difference of migrants are not apparent, but one possibility is that the longer-lived migrant generation has denser scalation to allow for scale loss over their lifespan. Alternatively, this effect could be confined to the subpopulation of monarchs in the Southeastern United States, which may not be well represented at the Mexican overwintering sites. In any case, this discovery highlights the many questions emerging on the significance of wing color variation in this species.


1982 ◽  
Vol 114 (2) ◽  
pp. 145-154 ◽  
Author(s):  
G. L. Ayre ◽  
W. J. Turnock ◽  
D. L. Struble

AbstractTests of intertrap variability in catches of moths of the clover cutworm, Scotogramma trifolii (Rottenberg), were conducted by placing two traps baited with an artifical sex attractant at 1 mi (1.6 km) intervals to form a grid covering 25 mi2 (64 km2) near Domain, Manitoba. The 50 traps (2/location) placed near the intersects of the grid were baited with a blend of Z-11-hexadecen-1-yl acetate and Z-11-hexadecen-1-ol. This blend was 98.6% species-specific for S. trifolii. Moth catches varied between traps and flights, but the ranking of the traps by catch was consistent during any given flight period. Up to 35 traps would be required within an area of 64 km2 (1 trap/1.8 km2) to give a population estimate within 20% of the true mean. Temperature influenced both the initiation of the flights and the number of moths caught at any given time, but there were no correlations between flights and precipitation or wind. Crop type influenced catches of S. trifolii only when moth populations were large. The catch of second generation moths averaged 9.8× the catch of first generation moths. The consistency of this relationship indicates that the annual differences in population density are controlled by variations in winter survival. The latter was linked to the induction of diapause which is governed by daylength during the larval development of the second generation.


1998 ◽  
Vol 16 (8) ◽  
pp. 2877-2885 ◽  
Author(s):  
H Takiuchi ◽  
J A Ajani

PURPOSE The second-generation oral anticancer agent UFT, a combination of uracil and tegafur (TGF), results in a higher fluorouracil (5-FU) concentration in the tumor tissues than is achieved by TGF or comparable doses of intravenous 5-fluorouracil. UFT has been extensively studied in Japan and has been in use in the Orient for many years, particularly for patients with gastric carcinoma. UFT has recently entered extensive investigations in North America and Europe. METHODS Relevant studies that have chronicled the establishment of UFT, its mechanism of action, preclinical toxicology, human pharmacokinetics, phase I studies, and activity against gastric carcinoma are described in detail. RESULTS The uracil in UFT slows degradation of 5-FU by dihydropyrimidine dehydrogenase (DPD), which results in sustained concentrations of 5-FU in blood and tumor tissues. UFT is well tolerated, but such toxic effects as nausea, vomiting, and diarrhea are dose- and schedule-dependent. In phase I pharmacokinetic studies, UFT given orally on a 28-day schedule resulted in blood concentrations comparable to those following low-dose continuous intravenous infusion of 5-FU. In patients with gastric carcinoma, UFT alone has a response rate of approximately 20%. In the adjuvant setting, UFT plus mitomycin appears superior to TGF plus mitomycin. In Japan, UFT is part of the standard adjuvant chemotherapy for gastric carcinoma. CONCLUSION UFT is one of the first second-generation oral 5-FU prodrugs under investigation in North America and Europe. The literature suggests UFT is well tolerated and has cellular pharmacokinetic superiority over the first-generation 5-FU prodrug TGF. UFT has a more favorable toxicity profile than intravenous 5-FU. The issues of efficacy, patient convenience, and quality of life need to be studied in controlled randomized trials.


1961 ◽  
Vol 93 (12) ◽  
pp. 1113-1140 ◽  
Author(s):  
L. Davies

Prosimulium fuscum Syme and Davies, P. mixtum S. and D. and P. fontanum S. and D. form a complex of closely-related and largely sympatric species formerly known in North America (Twinn, 1936; Stone and Jamnback, 1955) under the single name P. hirtipes Fries, a well known species in the northern Palaearctic. The first step in demonstrating the multiple nature of the forms grouped under this name in North America was taken by Rothfels (1956) who showed by study of rhe larval salivary gland chromosomes that at least three non-interbreeding forms were present in eastern Canada. L. Davies (1957a) concluded from a study of specimens of all life-stages that none of the North American forms agreed with European P. hirtipes. A further step in the process was afforded by the work of Syme and D. M. Davies (1958), which erected the three species named above as a result of anatomical study of cytologically defined material, and showed that adult females of P. fuscum and P. mixtum could be reliably separated, mainly by features of the genitalia. The present work may be considered as a further step in the study of the common Prosimulium of eastern North America, by providing information on their ecology, thus amplifying the cytological and anatomical conclusions arrived at in the papers cited above.


1964 ◽  
Vol 96 (8) ◽  
pp. 1117-1133 ◽  
Author(s):  
R. S. Forbes ◽  
L. Daviault

AbstractThe mountain-ash sawfly, Pristiphora geniculata (Htg.), a pest on Sorbus spp., is known to occur in Europe, Asia, and North America. It has two generations a year in eastern Canada but only one in northern Quebec. The first generation predominates. The sawfly overwinters as a larva in a cocoon in litter or soil. Adults emerge from late May to early July, and lay eggs in pockets between the epidermal lavers around the edges of leaflets. The eggs hatch in about a week and the larvae feed from two to three weeks. The second generation, which starts in late July, is usually small. Adults producing the first generation may come from both generations of the preceding year whereas adults producing the second generation stem only from the first. Parthenogenesis is facultative and arrhenotokous; about 61% of adults reared were females. The male larvae have four instars and the female five. Some larvae remain in diapause up to five years. Foliage consumption of female larvae was about 1.4 times that of male larvae.P. geniculata lacks adequate density-dependent control factors and an important limiting factor may be its scattered food supply. The introduction of parasites, predators, or disease organisms might be beneficial.


2018 ◽  
Vol 96 (12) ◽  
pp. 1353-1365 ◽  
Author(s):  
D.E. Meattey ◽  
S.R. McWilliams ◽  
P.W.C. Paton ◽  
C. Lepage ◽  
S.G. Gilliland ◽  
...  

Understanding full annual cycle movements of long-distance migrants is essential for delineating populations, assessing connectivity, evaluating crossover effects between life stages, and informing management strategies for vulnerable or declining species. We used implanted satellite transmitters to track up to 2 years of annual cycle movements of 52 adult female White-winged Scoters (Melanitta fusca (Linnaeus, 1758)) captured in the eastern United States and Canada. We used these data to document annual cycle phenology; delineate migration routes; identify primary areas used during winter, stopover, breeding, and molt; and assess the strength of migratory connectivity and spatial population structure. Most White-winged Scoters wintered along the Atlantic coast from Nova Scotia to southern New England, with some on Lake Ontario. White-winged Scoters followed four migration routes to breeding areas from Quebec to the Northwest Territories. Principal postbreeding molting areas were in James Bay and the St. Lawrence River estuary. Migration phenology was synchronous regardless of winter or breeding origin. Cluster analyses delineated two primary breeding areas: one molting area and one wintering area. White-winged Scoters demonstrated overall weak to moderate connectivity among life stages, with molting to wintering connectivity the strongest. Thus, White-winged Scoters that winter in eastern North America appear to constitute a single continuous population.


2020 ◽  
Vol 103 (4) ◽  
pp. 247-254
Author(s):  
Yu. V. Plugatar ◽  
А. К. Sharmagiy* ◽  
E. B. Balykina

Studies in the Crimea have shown that both on the southern coast and in the central foothill region, an adventive pest of plants of the genus Buxus - the boxwood fireweed (Cydalima perspectalis), develops in three generations. Caterpillars of the second - third instars hibernate; their emergence from diapause occurs in early April. The timing and duration of development of each of the three generations of the boxwood firefighter in the conditions of the Crimea were determined, the lifespan of the imago was determined, averaging about two weeks, with some individuals living for more than 20 days. The sex index in adults varies in different generations, depending on the living conditions. Thus, in the central foothill region in the first generation, the ratio of females and males reaches 2: 1, and in the second generation, both the proportion of males and melanistic individuals increases in comparison with typically colored butterflies. In each of the three generations, males emerged from pupae 3-5 days earlier than females. The fertility of melanistic females is higher than that of the typically colored. A spring-summer diapause was observed in caterpillars of II-III instars in the overwintered, first and second generations.


2016 ◽  
Vol 1 (1) ◽  
pp. 105-118
Author(s):  
Anita Pugliese ◽  
Julie Ray ◽  
Neli Esipova

This paper reports the results from Gallup’s global analysis of the likelihood of first-generation migrants, second-generation migrants and the native-born to send financial help in the form of money or goods to others inside or outside their respective country of residence. The findings in this paper are based on more than 450,000 interviews conducted through Gallup’s World Poll in 157 countries in 2012, 2013 and 2014. The sample includes more than 26,000 first-generation migrants and more than 20,000 second-generation migrants. The large sample enables Gallup to analyze first-generation migrants by the duration of their stay in their adopted country and compare their remittance behaviors with second-generation migrants and the native-born.


Author(s):  
Asaad Abdullwahab AbdulKarim ◽  
Waleed Massaher Hamad ◽  
Salah Ibrahim Hamadi

Abstract     The Frankfurt School is characterized by its critical nature and it is the result of the Marxist socialist thought as it contributed to the development of the German thought in particular and the Western thought in general through important ideas put forward by a number of pioneers in the various generations of the school and most notably through the leading pioneer in the first generation, Marcuse, and the leading pioneer of the second  generation, Habermas, whose political ideas had an important impact on global thinking and later became the basis of the attic of many critical ideas. In spite of the belief of the school members in the idea of the criticism of power and community, each had his own ideas that distinguish him from the others.


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