SPATIAL AND TEMPORAL VARIABILITY IN SEX ATTRACTANT TRAP CATCHES OF SCOTOGRAMMA TRIFOLII (LEPIDOPTERA: NOCTUIDAE) IN RELATION TO ITS BIOLOGY IN MANITOBA

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.

1982 ◽  
Vol 114 (11) ◽  
pp. 993-1001 ◽  
Author(s):  
G. L. Ayre ◽  
W. J. Turnock ◽  
D. L. Struble

AbstractTests of intertrap variability in catches of moths of the darksided and redbacked cutworms, Euxoa messoria (Harris) and E. ochrogaster (Guenée), were conducted by placing two traps for each species baited with synthetic sex attractants at 1.6 km (1 mi) intervals to form a grid covering 64 km2 (25 mi2) near Domain, Manitoba. These sex attractants were 93 and 99.6% species specific for E. messoria and E. ochrogaster respectively. Moth catches varied between traps and flights, but the ranking of the traps by catch for each species was consistent during any given flight period. Variability in intertrap catches of E. messoria indicated the moths were not evenly distributed throughout the test area and consequently a sex-attractant trap system with 1.6 km trap spacing is not suitable for monitoring population levels. For E. ochrogaster four traps within an area of 64 km2 would be required to give a population estimate within 20% of the true mean. The flights of E. messoria are not related to degree days and started abruptly and at the same time each year suggesting that development may be synchronized by the summer diapause of the prepupae. The flights of E. ochrogaster were related to degree day accumulations above a threshold temperature of 12.5 °C. Crops had no apparent influence on the distribution of moth catches for either species.


1983 ◽  
Vol 115 (12) ◽  
pp. 1573-1582 ◽  
Author(s):  
G. L. Ayre ◽  
W. J. Turnock ◽  
D. L. Struble

AbstractIntertrap variability in catches of moths of the cutworms Leucania commoides Guenée and Peridroma saucia (Hübner) was tested by placing two traps for each species baited with artificial sex attractants at 1.6 km (1 mi) intervals to form a grid covering 64 km2 (25 mi2) near Domain, Manitoba. During the flight periods of the test species the attractants were 86.5 and 93.6% species-specific for L. commoides and P. saucia respectively. Moth catches varied between traps and flights, but the ranking of the traps by catch for each species was consistent during any given flight of L. commoides and during the first flight of P. saucia. The low intertrap variability in numbers captured of both species indicated the moths were uniformly distributed in the area. For L. commoides 10 traps within an area of 64 km2 would be required to give a population estimate within 20% of the true mean and for P. saucia three traps would be needed. The flights of L. commoides started abruptly each year and appeared to be triggered by rainfall. Flights of P. saucia did not occur below 10 °C but otherwise weather had no apparent influence on the flights. It was concluded that the moths of this species are blown in from the south each spring. Neither species showed a consistent distributional relationship with crops.


1999 ◽  
Vol 89 (5) ◽  
pp. 455-463 ◽  
Author(s):  
D.A. Maelzer ◽  
M.P. Zalucki

AbstractRegression analyses of a long series of light-trap catches at Narrabri, Australia, were used to describe the seasonal dynamics of Helicoverpa armigera (Hübner). The size of the second generation was significantly related to the size of the first generation, to winter rainfall, which had a positive effect, and to spring rainfall which had a negative effect. These variables accounted for up to 96% of the variation in size of the second generation from year to year. Rainfall and crop hosts were also important for the size of the third generation. The area and tonnage of many potential host crops were significantly correlated with winter rain. When winter rain was omitted from the analysis, the sizes of both the second and third generations could be expressed as a function of the size of the previous generation and of the areas planted to lucerne, sorghum and maize. Lucerne and maize always had positive coefficients and sorghum a negative one. We extended our analysis to catches of H. punctigera (Wallengren), which declines in abundance after the second generation. Winter rain had a positive effect on the sizes of the second and third generations, and rain in spring or early summer had a negative effect. Only the area grown to lucerne had a positive effect on abundance. Forecasts of pest levels from a few months to a few weeks in advance are discussed, along with the improved understanding of the seasonal dynamics of both species and the significance of crops in the management of insecticide resistance for H. armigera.


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.


1987 ◽  
Vol 119 (6) ◽  
pp. 557-566 ◽  
Author(s):  
J.R. Byers ◽  
D.L. Struble ◽  
G.B. Schaalje

AbstractSex-attractant traps were used to monitor the relative abundances of eight species of cutworm and army worm moths at 81 locations in a 13 000-km2 (5000-mi2) area of southern Alberta from 1978 to 1983. Clover cutworm (Discestra trifolii (Hufn.)), variegated cutworm (Peridroma saucia (Hbn.)), bertha armyworm (Mamestra configurata Wlk.), and Leucania commoides Gn. were monitored during spring and early summer, and redbacked cutworm (Euxoa ochrogaster (Gn.)), darksided cutworm (Euxoa messoria (Harr.)), pale western cutworm (Agrotis orthogonia Morr.), and army cutworm (Euxoa auxiliaris (Grt.)) during late summer and fall.The ranking of moth catches among locations within years was highly consistent, indicating that the spatial pattern of abundance within the survey area remained stable during each flight period. The corollary is that differences in population levels among locations were being consistently detected. Most of the species also exhibited a considerable degree of consistency of pattern of abundance between consecutive years and to some extent over all years.Estimates of the variability associated with individual traps, between duplicate traps, and among locations were obtained for each species. The within-location variability was always much less than the among-location variability, indicating that a meaningful measure of the relative population level at each location was being obtained. When abundance levels approached economic thresholds the likelihood of moth catches in duplicate traps being within 20% of the mean catch for a location was usually greater than 80%. Year-to-year differences in mean trap catches were frequently significant at the 95% confidence level and the monitoring system could detect relatively small changes in population level between years. Season cumulative trap catches are a composite measure of abundance and the mate-searching activity of males. Weather conditions that restrict male activity are also likely to reduce oviposition by females. Cumulative trap catches may therefore be closely correlated with realized fecundity.


2018 ◽  
Vol 12 (4) ◽  
pp. 295
Author(s):  
Otong Zenal Arifin ◽  
Wahyulia Cahyanti ◽  
Anang Hari Kristanto

Suatu penelitian untuk melihat keragaman genetik tiga generasi ikan tambakan dalam program domestikasi telah dilakukan di Balai Riset Perikanan Budidaya Air Tawar dan Penyuluhan Perikanan, Bogor. Tujuan penelitian ini adalah untuk mengevaluasi keragaman genetik generasi tetua/awal (G0), generasi pertama (G1), dan generasi kedua (G2) dalam program domestikasi ikan tambakan. Pengujian keragaman genetik dilakukan dengan metode PCR-RAPD menggunakan tiga primer, yakni OPA-2, OPA-8, dan OPC-2. Hasil yang diperoleh menunjukkan adanya perbedaan jumlah (7-15) dan ukuran fragmen (200-2.800 bp) yang dihasilkan, dengan frekuensi kemunculan alel berkisar antara 0,00-1,00 dari 31 lokus. Enam fragmen dari OPC-2 (1.400 bp, 1.300 bp, 1.100 bp, 800 bp, 600 bp, 500 bp), lima fragmen dari OPA-2 (1.350 bp, 1.000 bp, 900 bp, 800 bp, 520 bp), dan dua fragmen dari OPA-8 (1.000 bp, 550 bp) merupakan fragmen marka spesifik ikan tambakan pada penelitian ini. Keragaman genetik ikan tambakan antar generasi tergolong rendah, dengan nilai persentase polimorfisme berkisar antara 6,45%-35,48% dan nilai heterozigositas berkisar antara 0,03-0,16. Terjadi penurunan polimorfisme dan heterozigositas dari generasi tetua/awal (G0) ke generasi pertama (G1) dan kembali naik pada generasi kedua (G2). Dalam program domestikasi, nilai efektif induk (Ne) sebaiknya lebih dari 100, dengan nilai laju inbreeding (F) tidak lebih dari 0,005.A study to examine the genetic diversity of three generations of kissing gourami under a domestication program has been conducted at the Research Institute for Freshwater Aquaculture and Fisheries Extension, Bogor. The purpose of this study was to evaluate the genetic diversity of the elder generation (G0), first generation (G1), and second generation (G2) of kissing gourami under the domestication program. The genetic diversity examination was conducted through a PCR-RAPD method using three primers, namely OPA-2, OPA-8, and OPC-2. The obtained results indicated a difference in the number (7-15) and size of the fragments (200-2.800 bp) with the frequency of allele occurrence ranged from 0.00 to 1.00 from 31 loci. Six fragments from OPC-2 (1,400 bp; 1,300 bp; 1,100 bp; 800 bp; 600 bp; 500 bp), five fragments from OPA-2 (1,350 bp; 1,000 bp; 900 bp; 800 bp; 520 bp), and two fragments from OPA-8 (1,000 bp; 550 bp) were considered as species-specific markers of kissing gourami. The genetic diversity among the generations of the kissing gourami was low, with the percentage of polymorphism ranged from 6.45% to 35.48% and the value of heterozygosity ranged from 0.03 to 0.16. There was a decrease in polymorphism and heterozygosity values from the elder generation (G0) to the first generation (G1) and increased again but on the second generation (G2). In addition, the effective breeding value (Ne) in a domestication program should be more than 100, and the average of inbreeding value (F) is less than 0.005.


1992 ◽  
Vol 124 (3) ◽  
pp. 541-551 ◽  
Author(s):  
G.H. Gerber ◽  
J. Walkof

AbstractThe phenology and reproductive status of adults of the redbacked cutworm, Euxoa ochrogaster (Guenée), were determined from blacklight (BLT) and sex-attractant (SAT) trap catches at four locations in southern Manitoba in 1987 through 1989. The flight period was of 9–12 weeks duration, extending from late June to early October. The first male and female moths were captured at about the same time in the BLT and SAT. The peak catches of the BLT occurred during the first 3 weeks of August (weeks 5 and 6 of the flight period) and those of the SAT about 1 week later. The SAT continued to capture male moths for 2–3 weeks after the last moths appeared in the BLT. Most females captured during the first 2–3 weeks of the flight period were virgins who had not yet initiated egg development. Most mating, egg development, and oviposition took place during a 3- to 4-week period that included the 2 weeks before, the same week as, and the week after the peak BLT catches (weeks 3–7 of the flight period); these activities occurred in the 3–4 weeks before the peak SAT catches. The data suggested that there was competition between SAT and females in attracting males and, consequently, the SAT catch data may not be providing accurate measurements of the sizes of breeding populations of males in the field. The BLT catches underestimated the length of the flight period by about 1.5–3 weeks.


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.


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