Effects of Moth Population Density and Pheromone Concentration on Mating Disruption of the Corn Earworm in Large Screened Cages12

1982 ◽  
Vol 75 (2) ◽  
pp. 333-336 ◽  
Author(s):  
J. E. Carpenter ◽  
A. N. Sparks ◽  
R. C. Gueldner
1986 ◽  
Vol 118 (8) ◽  
pp. 797-805 ◽  
Author(s):  
B.M. Ponder ◽  
L.R. Kipp ◽  
C. Bergh ◽  
G.C. Lonergan ◽  
W.D. Seabrook

AbstractFactors influencing spruce budworm (Choristoneura fumiferana) mating and mating suppression in an enclosed environment in the laboratory were investigated to develop a quantitative assay suited to statistical analysis. Mating in the absence of the two major components of spruce budworm sex pheromone (control) was not affected by changes in moth population density nor by increasing the experimental duration from 20 to 44 h. The proportions mated increased with an increase in the male:female ratio to 1.5:1 and when the experimental duration was prolonged to 68 h. Using a population density, sex ratio combination of 15:10 (male:female) the proportions of mated females decreased with increasing source concentrations of the two major spruce budworm sex pheromone components (95:5 E/Z-11–14-tetradecenal). This effect was diminished with increases in the population density and with extended test duration. Mating in the presence of pheromone remained lower than controls over all durations tested.


1997 ◽  
Vol 14 (3) ◽  
pp. 135-140 ◽  
Author(s):  
Kevin W. Thorpe ◽  
Richard L. Ridgway ◽  
Ralph E. Webb

Abstract Aerial applications of Bacillus thuringiensis Berliner subsp. kurstaki (74.1 billion international units/ha per application; single and double applications), diflubenzuron [69 g (ai)/ha], and no treatment were evaluated. Treatment effects were estimated from frass collections, defoliation, counts of pupae under burlap, and egg-mass counts. Estimates of larval density in the canopy 20 days after treatment ranged from 318.3 to 55.5 larvae per m² in the control- and diflubenzuron-treated plots, respectively. Larval density was reduced in all treatments, and was lowest in the plots treated with diflubenzuron and two applications of B. thuringiensis. Population density rapidly declined in the control plots, and by June 20, when larvae were predominantly in the fifth and sixth instars, no significant differences in larval density were detected among the treatments. Significantly less defoliation occurred to oak trees in the treated plots, but no differences were detected among the spray treatments. Counts of pupae under burlap, postseason egg-mass counts, and percent reduction in egg-mass density did not differ significantly among treatments or versus controls. These results suggest that diflubenzuron and double B. thuringiensis treatments caused higher levels of larval mortality than occurred with a single B. thuringiensis application, but that with a naturally declining gypsy moth population the final levels of damage were the same under all treatments. North. J. Appl. 14(3):135-140.


2008 ◽  
Vol 48 (4) ◽  
pp. 509-513 ◽  
Author(s):  
Hristina Kutinkova ◽  
Jörg Samietz ◽  
Vasiliy Dzhuvinov

Combination of Mating Disruption and Granulosis Virus for Control of Codling Moth in Bulgaria An application of mating disruption by use of Ecodian CP dispensers (ISAGRO, Italy) in combination with the granulosis virus product Carpovirusine 2000 (Arysta LifeScience, France) against Codling moth (CM), Cydia pomonella, was tested near Plovdiv, Central South Bulgaria. In 2007, the method was applied in an orchard where in the previous year fruit damage reached 18.7% and the CM population was high, as indicated by 3.83 diapausing larvae per tree. Carpovirusine was applied 11 times in the trial plot in combination with Ecodian CP dispensers installed twice during the season. Before harvest, fruit damage in the trial plot amounted to 0.9% and the overwintering population in autumn 2007 was only 0.46 larvae per tree. At the same time in the reference orchard, where 15 insecticide treatments were applied during the season, fruit damage before harvest reached 12.3% and the hibernating population was 7.97 larvae per tree. So, it has been confirmed that combination of both methods might be an effective tool for control of codling moth in the orchards with high population density and resistance to conventional insecticides. This study is being continued.


1978 ◽  
Vol 110 (9) ◽  
pp. 917-920 ◽  
Author(s):  
F. M. Stephen ◽  
G. W. Wallis

AbstractIn order to establish a functional relationship between damaged pine tips apparently infested with Nantucket pine tip moth, Rhyacionia frustrana (Comstock), and within-tip larval and pupal population, X-ray techniques were used to determine numbers of actually infested tips and the numbers of tip moth immatures contained therein. Linear relationships existed between these variables and changes in tip moth density. The effect of different plantations, tip moth generations, season, and tree age did not significantly alter the observed relationships. Approximately 40% of the damaged (i.e. apparently infested) tips were actually infested, and these tips contained an average of 1.4 tip moth immatures per tip. The equation Y = −.509 +.57X estimates the number of tip moth immatures, given the number of apparently damaged tips per tree (r2 =.71).


Insects ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 289
Author(s):  
Aitor Gavara ◽  
Sandra Vacas ◽  
Ismael Navarro ◽  
Jaime Primo ◽  
Vicente Navarro-Llopis

Mating disruption (MD) is widely used against the European grapevine moth (EGVM), Lobesia botrana (Denis and Schiffermüller; Lepidoptera: Tortricidae), by installing passive dispensers or aerosol devices. The present work reports a new sampling and quantification methodology to obtain absolute data about field airborne pheromone concentration based on air samplings and sensitive chromatographic-spectroscopic methods. Samplings were performed in fields treated with passive dispensers or aerosol devices at different moments throughout the crop cycle to study how they act and how the disruption is triggered. Moreover, pheromone adsorption and releasing capacity of vine leaves were studied to elucidate their role in the disruption. Although both types of dispensers were effective in limiting the damage inflicted by EGVM, they performed differently and provided different airborne pheromone concentration profiles. Results also proved that leaves were able to adsorb and release part of the airborne pheromone acting as subsequent and additional pheromone sources. This fact could explain the different concentration profiles. Moreover, our results suggest that lower pheromone emission than that of the current passive dispensers still could provide an adequate performance in the field. Competitive mechanisms involved in MD using both dispensers, the dynamics of the airborne pheromone throughout the time and the importance of the canopy are discussed.


2013 ◽  
Vol 21 (1) ◽  
pp. 65-70 ◽  
Author(s):  
Zofia Płuciennik

Abstract The series of experiments on codling moth (Cydia pomonella L.) control using mating disruption method were conducted in three experimental orchards during 2006-2010 growing seasons. The efficacy of two commercial pheromone preparations: Ecodian CP and Isomate CTT, in comparison to pesticides Calypso 480 SC and Appeal 04 PA, was evaluated on the base of percentage of damaged fruits, number of caterpillars collected during their migration for overwintering in bands of corrugated cardboard placed on tree trunk and number of moths caught in pheromone traps. Two thousands dispensers of Ecodian CP were used twice a season (at 6-week interval) on the area of 1 ha of the orchard. Five hundred of Isomate CTT dispensers were applied once a season on 1 ha of the orchard. In all the experiments, application of mating disruption method significantly reduced the level of apple damage; the control efficacy (calculated according to Abbott’s formula) ranged from 54.2% to 95.8%. The efficacy of chemical control ranged from 58.5% to 93.0%. The lower efficacy of mating disruption method was noticed in orchards with high codling moth population. The treatments also affected the number of caterpillars caught in bands of corrugated cardboard placed on tree trunk. In experiments where the codling moth was not controlled, the number of caterpillars per a band varied from 0.2 to 11.9 whereas in these where the pest was controlled chemically or by mating disruption method, their number varied from 1.4 to 2.8 specimens.


2012 ◽  
Vol 144 (3) ◽  
pp. 379-395 ◽  
Author(s):  
Marc Rhainds ◽  
Edward G. Kettela ◽  
Peter J. Silk

AbstractThe Canadian registration in 2007 of Disrupt SBW Micro-Flakes®, a pheromone-based product for control of spruce budworm,Choristoneura fumiferana(Clemens), paved the way for large-scale trials to test the practicality of mating disruption as a commercial pest management strategy. We review results from field and laboratory experiments on pheromone-based mating disruption of spruce budworm conducted from 1974 to 2008. Application of pheromone from the ground or the air consistently reduced the orientation of males toward pheromone sources. Mating disruption also reduced the mating success of caged or tethered females in 15 of 16 field studies where this parameter was recorded, but had only a limited effect on the mating success of feral females. No consistent difference in the density of egg masses in control and treated plots was observed, which has often been attributed to immigration of gravid females into pheromone-treated plots. Laboratory studies suggest that false-trail following is the predominant mechanism underlying mating disruption in spruce budworm. The enhanced mating success of females with increasing population density suggests that mating disruption should target low-density emergent populations during the initial phase of an outbreak. Constraints that may limit the potential of mating disruption as a management tool include (1) difficulties associated with obtaining accurate sampling estimates at low population density to forecast the onset of outbreaks, (2) potential behavioral adaptations by which females enhance their mating success when the atmosphere is treated with pheromone, and (3) long-range dispersal of females by flight.


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