A MODIFIED LIVE-TRAP FOR ASSESSING MATING DISRUPTION OF MICROLEPIDOPTERA

1993 ◽  
Vol 125 (6) ◽  
pp. 1135-1136 ◽  
Author(s):  
Sheila M. Fitzpatrick ◽  
James T. Troubridge

In field studies of pheromone-mediated mating disruption of lepidopteran pests, there are several ways to determine if mate location has been disrupted. One indirect method is to count the number of males caught in sticky traps baited with synthetic pheromone. A reduced catch in pheromone-treated plots relative to control plots shows that males were unable to find the source of synthetic pheromone and suggests that mating has been disrupted. More direct methods are: (1) to count the number of males attracted to sticky traps baited with virgin females; or (2) to assess the incidence of mating of (a) feral females collected in light-, bait- or other traps, (b) females caged with males in pheromone-treated areas, or (c) virgin females placed in the field and later retrieved. Females may be tethered with thread to non-sticky traps or partially dealated and placed on a “mating table” from which they cannot escape.

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Antje Torge ◽  
Rainer Haeckel ◽  
Mustafa Özcürümez ◽  
Alexander Krebs ◽  
Ralf Junker

Abstract It has been observed that the estimation of reference intervals of leukocytes in whole venous blood leads to higher upper reference limits (uRLs) with indirect methods than has been reported in the literature determined by direct approaches. This phenomenon was reinvestigated with a newer, more advanced indirect method, and could be confirmed. Furthermore, a diurnal variation was observed with lower values during the morning and higher values in the late afternoon and at night. This observation can explain why indirect approaches using samples collected during 24 h lead to higher uRLs than direct methods applied on samples collected presumably in the morning.


2020 ◽  
Vol 113 (6) ◽  
pp. 2883-2889
Author(s):  
Fabiana B Bacalhau ◽  
Patrick M Dourado ◽  
Renato J Horikoshi ◽  
Renato A Carvalho ◽  
Altair Semeão ◽  
...  

Abstract The pyramided genetically modified (GM) soybean [Glycine max L. (Merr.)] MON87751 × MON87708 × MON87701 × MON89788, expressing Cry1A.105, Cry2Ab2, and Cry1Ac from Bacillus thuringiensis Berliner, was approved for commercial use in Brazil. We conducted laboratory, greenhouse, and field studies to assess the efficacy of this Bt soybean against key soybean lepidopteran pests. Neonates of Anticarsia gemmatalis (Hübner) (Lepidoptera: Erebidae), Chrysodeixis includens (Walker), and Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) were exposed to Bt proteins in diet-overlay bioassays. MON87751 × MON87708 × MON87701 × MON89788 soybean and individual components were evaluated in laboratory (leaf disc), greenhouse (high artificial infestations), and in field conditions (natural infestations). Neonates of A. gemmatalis, C. includens, and H. armigera were highly susceptible to Cry1A.105 (LC50 from 0.79 to 48.22 ng/cm2), Cry2Ab2 (LC50 from 1.24 to 8.36 ng/cm2), and Cry1Ac (LC50 from 0.15 to 5.07 ng/cm2) in diet-overlay bioassays. In laboratory leaf disc bioassays and greenhouse trials, MON87751 × MON87708 × MON87701 × MON89788 soybean as well as the individual components were highly effective in controlling A. gemmatalis, C. includens, and H. armigera. Similarly, under field conditions, the pyramided genotypes expressing Cry1A.105, Cry2Ab2, and Cry1Ac were highly effective at protecting soybean against C. includens. We concluded that the individual Bt proteins expressed by GM soybean MON87751 × MON87708 × MON87701 × MON89788 killed all or nearly all the susceptible A. gemmatalis, C. includens, and H. armigera, fulfilling one important criterion for successfully delaying resistance to pyramided Bt crops.


1996 ◽  
Vol 31 (3) ◽  
pp. 277-285 ◽  
Author(s):  
R. R. Youngman ◽  
T. P. Kuhar ◽  
D. G. Midgarden

Field studies were conducted in Virginia cornfields in 1990 and 1991 to evaluate the effect of trap size on numbers of Diabrotica virgifera virgifera LeConte adults caught on unbaited Pherocon AM and Olson yellow sticky traps. No significant differences in trapping efficiency (i.e., catch per unit area) were detected on Pherocon AM traps whose sizes had been reduced by either 50% or 75% when compared with standard Pherocon AM no-bait traps. Likewise, no significant difference in trapping efficiency was detected between Olson traps whose sizes had been reduced 50% and full-size Olson traps (212.9 cm2). However, significantly more western corn rootworm adults per unit area were caught on Olson yellow sticky traps compared to Pherocon AM traps whose sizes had been reduced 50%. Comparative costs and precision values for reduced-size Pherocon AM and Olson yellow sticky traps are discussed.


Behaviour ◽  
2005 ◽  
Vol 142 (6) ◽  
pp. 717-729 ◽  
Author(s):  
David M. Suckling ◽  
Ashraf M. El-Sayed

Insects ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 285 ◽  
Author(s):  
Renato Ricciardi ◽  
Andrea Lucchi ◽  
Giovanni Benelli ◽  
David Maxwell Suckling

The citrophilous mealybug Pseudococcus calceolariae (Maskell) (Hemiptera, Pseudococcidae) is a primary pest of various crops, including grapevines. The use of insecticides against this species is difficult in most cases because its life cycle includes an extended duration of eggs, juveniles, and adults under the bark and on the roots. Pheromone-based control strategies can present new eco-friendly opportunities to manage this species, as in the case of Planococcus ficus (Signoret) and Planococcus citri (Risso). With this aim it is critical to understand behavioral aspects that may influence pheromone-based control strategies. Herein, the capability of males to fertilize multiple females was investigated, trying to understand whether this behavior could negatively impact the efficacy of mass trapping, mating disruption, or the lure and kill technique. Results showed that a P. calceolariae male can successfully mate and fertilize up to 13 females. The copulation time in subsequent mating events and the time between copulations did not change over time but the number of matings per day significantly decreased. In a further experiment, we investigated the mate location strategy of P. calceolariae males, testing the attractiveness of different loadings of sex pheromone on males in a flight tunnel. Males constantly exposed to 16 rubber septa loaded with the sex pheromone showed a significant decrease in female detection at 1 and 30 μg loadings (0.18 and 0.74 visits per female for each visit per septum, respectively), whereas in the control about 9.2-fold more of the released males successfully detected the female in the center of the array of 16 septa without pheromone. Male location of females in the control (45%) was significantly higher than in the arrays with surrounding pheromone (5% and 20% at 1 and 30 μg loadings, respectively). Mating only occurred in the control arrays (45%). This study represents a useful first step to developing pheromone-based strategies for the control of citrophilous mealybugs.


Insects ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 589
Author(s):  
Gabriella Lo Verde ◽  
Salvatore Guarino ◽  
Stefano Barone ◽  
Roberto Rizzo

Control of the plum fruit moth, Grapholita funebrana Treitschke (Lepidoptera: Tortricidae), has been mainly based on the use of chemical insecticides, which can cause undesirable side effects, leading to a growing interest towards alternative sustainable strategies. The aim of this study was to evaluate the effect of the mating disruption technique on G. funebrana infestation in plum orchards, by comparing the number of male captures in pheromone-baited traps, and evaluating the damage to fruits in plots treated with the pheromone dispersers and in control plots. The study was carried out in 2012 and 2014 in three organic plum orchards, on the cultivars Angeleno, Friar, President and Stanley. To evaluate the pheromone emission curve of the dispensers from the openings to the end of the trials, a chemical analysis was carried out by solid phase micro-extraction followed by gas chromatography, followed by mass spectrometry. In all years and orchards the mean number of males caught in traps placed in the treatment plots was always significantly lower than untreated plots. Pheromone emission from the dispensers was highest at the opening, and was still considerable at 54 days of field exposure, while it significantly decreased after 72 days of field exposure. Cultivar was confirmed to be an essential factor in determining the fruit infestation level. Pheromone treatment significantly reduced fruit infestation, but not economic damage.


1999 ◽  
Vol 34 (2) ◽  
pp. 219-224 ◽  
Author(s):  
Roger N. Williams ◽  
Donn T. Johnson ◽  
E. Priesner

Male moths of the horse nettle borer, Synanthedon rileyana (H. Edwards), were attracted to various blends of (E,Z)-3,13-ODDOH alcohol and (E,Z)-3,13-ODDA acetate. Fields containing horse nettle, Solanum carolinense L., were utilized in Ohio and Arkansas during these attractancy trials in 1988 and 1989. Efficacy was determined by the number of males trapped in sticky traps. The optimum ratio of alcohol to acetate was found to be 100:25 to 100:50 confirming earlier observations and expanding the knowledge through replicated experiments in two states. A second blend of 100:3 (E,Z)-3,13-ODDOH and (E,Z)-2,13-ODDA also attracted more males than the blank traps did at both locations. Seasonal moth emergence, reflected by the number of male moths trapped, begins in Ohio in mid-July and peaks by mid-August.


Twin Research ◽  
2002 ◽  
Vol 5 (1) ◽  
pp. 19-29 ◽  
Author(s):  
Johan Fellman ◽  
Aldur W. Eriksson

AbstractIn many studies the twinning rate, being strongly dependent on maternal age (and parity), has been standardised according to the maternal age distribution. The direct method requires very informative twinning data for the target population. The indirect method is used when the data for the target population is not sufficiently informative or when the target population is small. We have earlier introduced an alternative indirect technique for standardising the twinning rate. Our technique requires even less of the twinning data. Besides maternal age, parity is an influential factor, and should, if possible, be taken into account. In this study we present the traditional standardisation methods based on both maternal age and parity, we propose a new direct standardisation method and we develop our standardisation methods so that they take into account both maternal age and parity. We apply these standardisation methods to data from Finland, 1953–1964, from St. Petersburg, Russia, 1882–92, from Canada 1952–1967, and from Denmark, 1896–1967. These methods all give results very similar to those for the Finnish data, but the effect of parity is strongest with the direct methods. This may be due to the fact that, among extramarital maternities, parity has a strongly increasing effect on the twinning rate. This may be attributed to a higher reproduction capacity among unmarried mothers. Standardisations of the Canadian and the Danish data also give reliable results. With the St. Petersburg data, however, the different standardisations show notable discrepancies. These discrepancies are compared with Allen’s findings.


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