Trapping female cabbage root flies (Delia radicum (L.)) (Diptera: Anthomyiidae) with allylisothiocyanate-Baited traps

1982 ◽  
Vol 72 (1) ◽  
pp. 165-173 ◽  
Author(s):  
S. Finch ◽  
G. Skinner

AbstractField experiments in England with traps baited with allylisothiocyanate (ANCS) showed that females of Delia radicum (L.) were distributed more or less evenly through established brassica crops. Reducing the quantity of ANCS released from the traps either by diluting the concentrate with liquid paraffin or by presenting the concentrate in Wädenswil dispensers reduced the numbers of females caught. There was no indication that ANCS became repellent, even when released at a rate of 24 ml/trap per day. For maximum effectiveness, the ANCS dispenser had to be placed at the centre rather than at the edge of the trap. Attempts to make traps more effective by releasing the ANCS from several point sources around a trap, in the hope that this broader odour plume would ‘ attract ’ more flies, were unsuccessful. The ANCS-baited trap had an effective zone only 5 m in radius.

2002 ◽  
Vol 82 (3) ◽  
pp. 599-610 ◽  
Author(s):  
L. M. Dosdall ◽  
R. -C. Yang ◽  
P. M. Conway

While the importance of sulfur nutrition for the development of healthy stands of canola is well documented, the role of sulfur in the management of insect pest infestations has not previously been investigated in this crop. Field experiments were conducted at three sites in central Alberta in 1997 and 1998 to determine the influence of sulfur and sulfate applications on infestations of root maggots (Delia spp.) (Diptera: Anthomyiidae) in canola (Brassica rapa L.). Different formulations (granules, powder, prills, and sprays), application methods (either drilled in with the seed or top-dressed on the soil surface), and application rates were evaluated. To assess the degree of root maggot infestation, oviposition throughout the season and damage to taproots at the end of the season were monitored. Sulfur contents were analyzed from leaf samples collected mid-season and seed yields were measured from all treatment plots. Root maggot responses to the different sulfur treatments and application methods varied among years and sites, indicating that environmental factors have great importance in determining infestation levels by these pests, and the oxidation rate of elemental sulfur in soil. Sulfur formulation and application rate had significant effects on root maggot egg deposition and root damage for some sites and years, but even at high rates of application (112 kg ha-1) reductions in infestation levels were not substantial relative to the controls. While sulfur additions alone will not greatly reduce root maggot infestation levels in canola, growers should employ adequate sulfur nutrition for optimum crop health to enable plants to better compensate for damage by these pests. Key words: Brassica rapa, Delia radicum, Delia floralis, elemental sulfur, sulfate, canola


Insects ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 733
Author(s):  
Carl W. Doud ◽  
Thomas W. Phillips

A series of laboratory and field experiments were performed to assess the responses of Tribolium castaneum (Herbst) and other stored-product beetles to pheromone-baited traps and trap components. A commercial Tribolium pitfall trap called the Flit-Trak M2, the predecessor to the Dome trap, was superior in both laboratory and field experiments over the other floor trap designs assessed at capturing walking T. castaneum. In field experiments, Typhaea stercorea (L.) and Ahasverus advena (Stephens) both preferred a sticky trap to the pitfall trap. Although the covered trap is effective at capturing several other species of stored product beetles, the synthetic Tribolium aggregation pheromone lure is critical for the pitfall trap’s efficacy for T. castaneum. Although the food-based trapping oil used in the pitfall trap was not found to be attractive to T. castaneum when assayed alone, it had value as an enhancer of the pheromone bait when the two were used together in the trap. A dust cover modification made to go over the pitfall trap was effective in protecting the trap from dust, although the trap was still vulnerable to dust contamination from sanitation techniques that used compressed air to blow down the mill floors. Capture of T. castaneum in the modified trap performed as well as the standard trap design in a non-dusty area of a flour mill, and was significantly superior over the standard trap in a dusty area. T. castaneum responded in flight outside a flourmill preferentially to multiple funnel traps with pheromone lures compared to traps without pheromone.


2013 ◽  
Vol 14 (1) ◽  
pp. 57-78
Author(s):  
Alexander Grakovski ◽  
Yuri Krasnitski ◽  
Igor Kabashkin ◽  
Victor Truhachov

Abstract Some possibilities of fibre-optic sensors (FOS) application for measuring the weight of moving vehicles realized in weightin- motion (WIM) systems are discussed. As the first, the model of small-buried seismic sensor transient response excited by a car tyre interaction with asphalt-concrete road pavement is proposed. It is supposed that a seismic wave received by the sensor is the vertical component of surface Raleigh wave. The model is based on supposition that a tyre footprint is acceptable to consider as some array of point sources of these waves. The proper algorithms permit to vary different parameters of the array excitation, as to footprint dimensions, load distribution, car velocities and others. The set of Matlab codes is worked out for seismic pulses modelling and processing. The second way considered is to simulate the FOS signal in the basis of differential equations describing a deformable wheel behaviour, or wheel oscillations, in order to identify relations with optoelectronic mechanical parameters. An attempt to find the mass of the vehicle is based on minimizing the discrepancy between the actual FOS signal and the solution of the differential equation. The accuracy of the evaluated weight depends on many external factors, the mathematical modelling of them are expressed in the numerical values of the coefficients and external stimuli. The influence of these factors are analysed and tested by simulations and field experiments. One of ideas in dynamic weighing problem solution should consist in evaluation of position of virtual gravity centre of the vehicle in time. The processing algorithm of the data received from the FOS is proposed based on conception of database retaining in some reference system memory. Certain requirements concerning the elements and blocks of the algorithm are defined as well. The reference system is realized as the digital filter with the finite impulse response. The method to estimate the filter coefficients is worked out. Several experiments with this algorithm have been carried out for the vehicle identification with the reference loads adopted from real data. The different factors have an influence on the measurement accuracy of FOS. The roadbed features, temperature, nonlinearities and delay effects in FOS are among them. The results of laboratory and field measurements with FOS responses to different axle’s loadings are presented. Charging and inertial characteristics of FOS under the impact of various external factors (protective cover, temperature, contact area, and installation mode especially) as well as their approximations are investigated. It is found that the final calibration of the FOS has to be done individually and only after it has been installed in the pavement. Certain methods and algorithms of linearization, as well temperature and dynamic errors compensation of FOS data are discussed.


2001 ◽  
Vol 36 (3) ◽  
pp. 259-267 ◽  
Author(s):  
Mary L. Cornelius ◽  
Jian J. Duan ◽  
Russell H. Messing

Methyl eugenol is an extremely effective attractant for male oriental fruit flies, Bactrocera dorsalis (Hendel). Field experiments were conducted in a commercial guava orchard to determine whether the presence of methyl eugenol-baited traps affected the distribution and abundance of female oriental fruit flies near the traps. Captures of females on spheres did not increase within the vicinity of methyl eugenol-baited traps. Captures of males were significantly greater on spheres hung in trees containing methyl eugenol-baited traps than on spheres hung in other trees. An experiment was conducted to determine if methyl eugenol would influence the dispersal of unmated, sexually mature female oriental fruit flies. There were no significant differences in the numbers of marked or wild females captured on traps at different distances from the methyl eugenol lure. This study did not find any evidence that the presence of methyl eugenol-baited traps in orchards would affect female abundance in the vicinity of traps.


Author(s):  
Brian Morton

Aspects of the feeding behaviour of Ergalatax contractus (Muricidae) were studied. Field experiments demonstrated that large numbers of individuals of this species, comprising ∼90% of a suite of gastropod scavengers, were attracted to baited traps in the subtidal sands of Lobster Bay, Cape d'Aguilar Marine Reserve, Hong Kong. Laboratory experiments identified the effective chemo-detection distances of E. contractus as 60 cm in still and >80 cm in flowing water, respectively. The average times to arrival at bait in still and flowing water were 92.3 and 69.0 min, respectively, but were significantly less for individuals experiencing a longer period of starvation. The mean time taken for E. contractus to consume a meal was 70.6 min.Comparisons were made between Ergalatax contractus and Nassarius nodifer, representative of a suite of sympatric scavenging nassariids in Lobster Bay. The nassariid arrived significantly faster at bait in both still (30.2 min) and flowing water (20.8 min) than E. contractus and fed faster (25.7 min), as is typical of representatives of the Nassariidae. Although the two species partition carrion resources temporally, manipulation experiments provided evidence for inter-specific competition between them. That is, although E. contractus possesses the morphological and behavioural characteristics of a predator, its opportunistic scavenging abilities have led to its success and numerical superiority on the shallow subtidal sands of Lobster Bay. The dominance of E. contractus in Lobster Bay, and elsewhere in Hong Kong, is unusual. Here, the normally predatory E. contractus, far outnumbers all other scavengers, possibly because of an enhanced, largely allochthonous, supply of food which it is able to exploit by virtue of its previously identified opportunistic habit of scavenging the leftovers of other predators. The presence of inter-specific competition between E. contractus and a sympatric suite of nassariids enhances, not impedes, carrion exploitation.


2020 ◽  
Vol 49 (5) ◽  
pp. 1127-1136
Author(s):  
Nicholas L Grocock ◽  
Maya L Evenden

Abstract The bertha armyworm (BAW) Mamestra configurata Walker is a significant pest of canola Brassica napus L. (Brassicales: Brassicaceae) in western Canada. Its activity is monitored through a large network of pheromone-baited monitoring traps as a part of the Prairie Pest Monitoring Network across the Canadian Prairies. The unintentional bycatch of bee pollinators in pheromone-baited traps targeting moth pests occurs in many agroecosystems and may have repercussions for biodiversity and pollination services of wild plants and managed crops. We conducted field experiments to determine the abundance and diversity of bees attracted to green-colored BAW pheromone-baited traps across the canola growing regions of Alberta, Canada. A higher species diversity and more bumble bees were captured in BAW pheromone-baited than in unbaited control traps. Bombus rufocinctus Cresson (Hymenoptera: Apidae) was the most commonly captured species. Few other wild bees or honey bees Apis mellifera L. (Hymenoptera: Apidae) were captured during this study. Additionally, we evaluated the influence of local and landscape-level habitat features on bee bycatch. Local flowering plant abundance improved overall model fit but did not directly impact bee bycatch. The proportion of natural and seminatural habitat, and especially forested area, in the area surrounding monitoring traps affected bee bycatch. Both local and landscape-scale factors were important in this study and often have combined effects on bee communities. This study provides recommendations to reduce the bycatch of beneficial bee pollinators in a large-scale pheromone-baited monitoring network.


1976 ◽  
Vol 66 (2) ◽  
pp. 243-265 ◽  
Author(s):  
R. J. Marks

AbstractThe synthetic sex pheromone of Diparopsis castanea Hmps., dicastalure, is a 4:1 synergistic combination of 93% trans:7% cis-9,11-dodecadien-1-yl acetate (IV) and the unattractive compound 11-dodecen-1-yl acetate (IIB). Both cis and trans-9-dodecen-1-yl acetate (IIA), the latter occurring in the female pheromone gland, are potent inhibitors of male attraction, as little as 10–4 mg IIA significantly reducing the attractiveness of virgin females in pheromone traps for more than one month in the field. Inhibition is typically close range, although higher concentrations are inhibitory when placed at up to 1 m from the female. IV and IIB also reduce male catch in female-baited traps, but dicastalure does not. Recently mated females, confined with virgins, reduce male catch, thereby indicating release of an unknown inhibitor. When formulated in a suitable extender, such as corn-oil, dicastalure may be released from sealed polyethylene vials or from cellulose acetate cigarette filters, and inclusion of the antioxidant 2:6-di-tort-butyl-p-cresol (BHT) prolongs the attractiveness of 1 mg dicastalure formulations beyond 25–30 days. Release from polyethylene is more efficient than from either polypropylene or cellulose and moth catch over a five-week period is linearly related to the logarithm of pheromone concentration. Significant communication disruption, as measured by reduced trap catches of male Diparopsis, occurred when female-baited traps in 100 m2 cotton plots were surrounded by point sources of either dicastalure (synthetic females) or the inhibitory IIA acetate (anti-females). Since dicastalure is occasionally less attractive than virgin females, efforts are being made to improve pheromone slow release formulations.


1998 ◽  
Vol 130 (2) ◽  
pp. 153-162 ◽  
Author(s):  
Robert S. Vernon ◽  
John R. Mackenzie

AbstractA specially constructed fence was developed to exclude cabbage flies, Delia radicum (L.), from plantings of rutabaga. The number of first-flight female D. radicum caught on traps inside fenced enclosures declined linearly with fence height from 0 to 90 cm. Females caught in plots surrounded by a 90 cm high fence were 80.6 and 82.8% fewer than in open check plots in 1991 and 1992, respectively. The percentage of transplanted rutabagas killed by cabbage maggot in the 90 cm high enclosures was 1.4% in 1991 and 25.5% in 1992, compared with 11.8 and 84.5% in the open check plots, respectively. The mean damage index rating for rutabagas was severe in the open check plots but slight in the 90 cm high enclosures in 1991. Only 1.2% of rutabagas in the open check plots would have been of marketable grade in 1991, compared with 54% in the 90-cm enclosures. The mean damage rating was highest in the open check plots in 1992, but damage was also severe in all fenced plots due to the heavy infestation levels that year. The potential of exclusion fences for use in pest-management programs for rutabagas and other brassica crops is discussed.


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