Trap Exposure Research Articles

Long-term drifts of stray electric fields in a Paul trap

We investigate the evolution of quasi-static stray electric fields in a linear Paul trap over a period of several months. Depending on how these electric fields are initially induced, we observe very different timescales for the field drifts. Photo-induced electric fields decay on timescales of days. We interpret this as photo-electrically generated charges on insulating materials which decay via discharge currents. In contrast, stray fields due to the exposure of the ion trap to a beam of Ba atoms mainly exhibit slow dynamics on the order of months. We explain this observation as a consequence of a coating of the trap electrodes by the atomic beam. This may lead to contact potentials which can slowly drift over time due to atomic diffusion and chemical processes on the surface. In order not to perturb the field evolutions, we suppress the generation of additional charges and atomic coatings in the Paul trap during the measurements. For this, we shield the ion trap from ambient light and only allow the use of near-infrared lasers. Furthermore, we minimize the flux of atoms into the ion trap chamber. Long-term operation of our shielded trap led us to a regime of very low residual electric field drifts of less than 0.03 V/m per day.

Dynamics of abundance of ground beetles (Coleoptera, Carabidae) in fenced areas in the Cis-Altai plain (Western Siberia)

The density of ground beetle populations was estimated by means of fenced pitfall traps in 2004–2008, in the environs of Biisk (Altai Territory) and Karasuk (Novosibirsk Province). In all, 64 species of ground beetles were revealed. The capture rates were usually higher in open than in fenced plots. No correlation was observed between the time of trap exposure and the captures. By the end of the 3rd–6th week of exposure, the fraction of juvenile and immature adults increased. The beetles captured within a fenced area 1 m2 usually fell into the traps in 2–3 days. The maximal density of carabids in the fenced areas was estimated at 55–60 ind./m2.

Comparison of Different Uses of Adult Traps and Ovitraps for Assessing Dengue Vector Infestation in Endemic Areas

This report presents a set of field experiments designed to assess different protocols for the use of ovitrap and MosquiTRAP, a promising new trap for dengue vector monitoring. Percentage of positive houses, calculated either by the use of 2 traps (outside + inside) or 1 trap (outside) per house, tended to increase with time of exposure, at similar rates. When the aim was either to obtain a qualitative index (Aedes aegypti-positive site) or to determine percentage of positive houses in a selected neighborhood, the use of 1 ovitrap per house with only 5 days of exposure at the peridomestic area was quite sensitive. Seven days of exposure was too long, as saturation is expected in some places. The number of eggs collected per site increased with the time of exposure in all sites. At the 3-day trap exposure, we were not able to discriminate neighborhoods in terms of egg productivity per house. At the 5-day trap exposure, a rank of 4 sites was achieved. There was no correlation between the number of adults caught in MosquiTRAPs and number of eggs collected in ovitraps, neither per neighborhood nor per house where both traps were simultaneously exposed for 7 days in the peridomestic area.

1998 Results of Monitoring Diabrotica virgifera virgifera LeConte in Croatia

In 1998, 90 monitors were placing traps on 136 sites in Croatia. One pheromone and one Multigard trap was placed at each site. Trapping began 25 June. Both trap types were replaced with new traps at 25 days intervals. Sixty-two (45.6%) sites were located in previously infested regions, 37 (27%) along the line of spread in 1997, and 37 (27%) within uninfested areas. Ten permanent sites were established. At 4 these sites after a WCR beetle was captured, a ring with 12 additional traps was established. The fast catch was recorded the day following initial trap exposure, i.e. 26 June. This fact shows the need of an even earlier start of the monitoring action. The last catch was recorded on 5 October. Altogether 5.933 beetles were captured. Approximately 95% of all beetles captured occurred on pheromone traps whereas, approximately 5% of the beetles captured occurred on Multigard traps. The highest capture rate was recorded between July 10 and 31 August. The increase factor of the population density in 1998 was 2.8. In 1998, WCR spread west (37 km) to the village Gornji Varos 150 km from the Yugoslav border and 150 km from the Slovenia border. This spread occurred along the Sava river, which is the shortest pathway to western Europe. In the middle part of north Croatia, WCR spread only 8 km to the west spaces. In the northern part of Croatia, along the Croatia-Hungary border no further spread was recorded. Altogether an area of almost 10,000 km 2 is infested with WCR in which approximately 140,000 ha of corn is grown.

Seasonal Flight of Plecia nearctica (Diptera: Bibionidae) in Southern Florida

The lovebug, Plecia nearctica Hardy, is a serious nuisance to motorists traveling in southern states. The insects are smashed against windshields obscuring vision and cars may overheat when radiators become clogged. The smashed insects also damage car paint if the body fluids are not removed soon after contact (Callahan and Denmark 1973). The insect was first described by Hardy (1940) from Galveston, Texas, who reported it to be widely spread, but more common in Texas and Louisiana than other Gulf Coast states. It has now progressed to all states bordering on the Gulf of Mexico, as well as Georgia, South Carolina, and parts of Central America. It was first collected in Florida in 1949 and today is found throughout Florida (Denmark and Mead 1992). Adult flights of lovebugs have been reported to occur primarily during May and September in different areas of the insect's range (Hetrick 1970; Callahan and Denmark 1973; Buschman 1976; Thornhill 1976; Callahan 1985). However, in spite of these previous reports, no data have ever been presented actually showing seasonal flights of the lovebugs. Our objective was to determine seasonal flight patterns of P nearctica in southern Florida. Additional data on temporal sychronony of flights at different locations are also presented. Yellow sticky traps (Pherocon AM, no bait) made by Trece Inc., Salinas, California and baited with anethole (Cherry 1998) were used to monitor adult flights of lovebugs. Sampling was conducted by putting out 15 new sticky traps each month at approximately mid-month. These 15 traps were located at three different locations (5 traps/ location) to provide data on temporal synchrony between locations. One location was the Everglades Research and Education Center (location one), University of Florida, located near Belle Glade, Florida. The other two locations were located approximately 24 km southwest of the research center (location two) and 31 km east of the research center (location three). All three locations were located within Palm Beach County, Florida, and surrounded by agricultural lands (sugarcane, rice, vegetables). Traps at each location were placed 250 m apart in a straight line (i.e. a one km transect) adjacent roads. Each trap was hung one m above the ground on a metal rod and had a sponge (3 x 3 x 3 cm) containing 5 ml of anethole wedged into it. All 15 traps were hung and baited on the same day and collected seven days later. The seven day exposure period was used to avoid short term inclement weather factors such as rain, extreme winds, etc. that might greatly reduce adult catches within a shorter trap exposure time. Traps were collected by wrapping each trap in clear cellophane in the field. Lovebugs on each trap were counted by microscopic identification in a laboratory. A sample of lovebug adults collected on the traps during different major flight periods (May, September, December) was sent to Dr. Gary Steck, Division of Plant Industry, Gainesville, Florida who corroborated that the insects were P nearctica. Statistical analysis was conducted by SAS (1996). Temporal synchrony of adult flights between locations was determined by multiple correlation using the total number of adults caught each month at each location. Differences in mean numbers of adults caught at each location during different months were determined by using Tukey's test. A figure to visually show the overall seasonal flight pattern of the lovebugs is also presented. Although different numbers of lovebugs were observed between locations (Table 1), there was temporal synchrony in flight between locations. Multiple correlation of

Choice of trap exposure time for collection of invertebrate drift samples : Zadorina, V.M., 1987. Hydrobiol. J. (a translation of Gidrobiol. Zh.), 23(2):82–86. Polar Res. Inst. of Mar. Fish. and Oceanogr., Ministry of Fish., Acad. of Sci., Murmansk, USSR

Choice of trap exposure time for collection of invertebrate drift samples : Zadorina, V.M., 1987. Hydrobiol. J. (a translation of Gidrobiol. Zh.), 23(2):82–86. Polar Res. Inst. of Mar. Fish. and Oceanogr., Ministry of Fish., Acad. of Sci., Murmansk, USSR

Role of herbivory in controlling phytoplankton abundance: annual pigment budget for a temperate marine fjord

An annual pigment budget was constructed for Dabob Bay, Washington (USA) by comparing the downward vertical loss of phytoplankton pigments (chlorophyll and pheopigments) to the production of chlorophyll within the euphotic zone. The vertical flux of pigments was measured with sediment traps deployed at intervals of 1 to 6 wk over a 2.5 yr period yielding 763 d of trap exposure (28 November 1978–16 June 1981). The production rate of chlorophyll was calculated from measurements of algal specific growth rates, chlorophyll (chl) crops, primary production (as carbon) and appropriate C: chl ratios. Sixty one to 77% of the annual chlorophyll production was accounted for by the vertical flux of pheopigments resulting from herbivorous zooplankton grazing (macrozooplankton). Algal sinking, represented by downward chlorophyll flux, accounted for only 5 to 6% of the annual chlorophyll production. The remaining fraction of chlorophyll production was estimated to be consumed by small herbivores (microzooplankton), whose fecal material contributes to the suspended pool of pheopigments found in the euphotic zone. The suspended pheopigments are continuously removed by photodegradation. In Dabob Bay, the major process controlling phytoplankton abundance is zooplankton grazing and it appears that the ultimate fate of most phytoplankton is to be consumed by herbivores.

Evaluation of (Z)-5-Decen-1-ol as an Attractant for Male Larch Casebearer Moths, Coleophora laricella

Electroantennogram studies on C. laricella males demonstrated that the title compound, (Z)-5-decen-l-ol (Z5-10:OH), elicited the highest response among a series of straight-chain, C10 to C16 alcohols, acetates and aldehydes tested. From selective adaptation of antennal responses it was concluded that an additional type of receptor cell responded to the corresponding acetate, Z5-10: Ac. Field attraction experiments were carried out by using delta-type sticky traps and rubber-cap odour dispensers. The main test sites were located in the Swiss Alps, Black Forest and northwestern Germany, and included both European and Japanese larch stands, having different degrees of C. laricella infestations. At all test sites pure Z5-10:OH proved to be highly attractive to native male moths over a range of different lure doses, with a progressive increase of captures towards the higher (100 μg, 1000 μg) attractant sources. However, following captures of 200-400 moths/trap the “retaining capacity” of the sticky surfaces of the traps were found to decline markedly; in tests of the higher attractant doses at sites of higher moth densities, this “saturation effect” frequently occurred within a few hrs of trap exposure, thus demonstrating the limitation in the use of sticky traps for monitoring economically-relevant C. laricella populations. Trap placement studies (using the standard attractant of 100 μg Z5-10:OH) showed substantial captures only for those traps placed on green branches within the host crowns. The acetate analogue (Z5-10:Ac) strongly reduced male responses to the attractant alcohol (Z5-10:OH) when evaporated from the same trap, admixtures of 0.3% and 1% of this acetate reducing captures by 90% and almost 100% respectively. Possible functions of this inhibitor are briefly considered. No evidence for attractant synergism was obtained during the present study. The results suggest that Z 5-10: OH is a major constituent of the yet unidentified C. laricella sex pheromone.

In situ calibration of a sediment trap1,2

A relatively small self‐contained sediment trap with a timed closing system was deployed in Dabob Bay, Washington, for 1 year. Samples were collected representing 326 trap exposure days. An in situ calibration was obtained by comparing the capture and retention of unsupported 210Pb by the traps with the steady state accumulation rate of unsupported 210Pb in the underlying bottom. The efficiency of the traps to collect a representative sample of the sedimenting material is 118%.

Paleomagnetic Study of Deccan Traps from Jabalpur to Amarkantak, Central India

Results of paleomagnetic studies of twenty-four flows sampled from the area between Jabalpur (23°11′N, 77°58′E) and Dindori (22°57′N, 81°00′E) in the northeast part of the Deccan trap exposure are presented. The elevations of the flows varied from 372m to 670m above mean sea level. The results reveal the presence of a field reversal quite different from the one studied by earlier workers. Presence of this field reversal has been recently indicated by PAL et al. and WENSINK, in the Malwa and Nagpur regions, respectively. A comparison of the paleomagnetic results of the Deccan volcanics from different areas with those of normal polarity from Jabalpur-Dindori region indicates that the land mass of India drifted northward by about 21° during the entire period of the igneous activity represented by the Deccan traps.

Sex Ratio in Deer Mouse Populations

Studies of deer mouse populations in nature have recorded significantly more males than females (.005 > P). Since most studies have utilized trapping techniques, greater wandering tendencies of males and consequently greater trap exposure have been suggested to explain the excess males recorded. Tabulation of the sex ratios at birth of more than 500 litters from a laboratory colony of Peromyscus maniculatus bairdii indicate significantly more males than females produced (.025 > P). Excess production of males has also been recorded for freely growing laboratory populations of the same species. Peromyscus therefore, appears to be an additional genus exhibiting aberrant sex ratios.

(3) On Globular Structure in a Trap Rock near Neilston, Renfrewshire

This exposure of globular trap occurs near Shilford, on the line of the new Lanarkshire and Ayrshire Railway. The balls are about 6 feet in diameter, and occur near the bottom of a section 30 feet deep. None were seen touching each other, every one being enclosed in recently-decomposed trap. The outer portion of each globe, for about a foot deep, was traversed by thin veins, the principal ones being concentric, and the smaller ones reticulating with the longer ones, and sometimes crossing them. Along the sides of several the trap was altered, and lighter-coloured than the rest, an alteration quite different from the recent weather alteration on the outside of the globes. The balls do not impinge on one another, 30 that their sides are not flattened, nor are they arranged over each other as in columnar trap. Inside them the rock is remarkably solid and veinless. In one a joint is seen passing through, but it does not cross the veins. This internal part—about 4 feet in diameter—is dark grey, and slightly porphyritic, the outside coating with veins being dirty-white. There has clearly been a shrinkage of the outer crust of each large globe, and a subsequent infilling of the cracks so produced, though before this took place these parts of the balls must otherwise have been as solid as the centres still are. (See fig. 4.) This 250-word extract was created in the absence of an abstract

Fossils in Trap

WHEN examining the great exposure of trap and associated Upper Silurian rocks at Cape Bon Ami, New Brunswick, I unexpectedly found fossils in the trap. I was at the time collecting agates and amygdals of calcite. One amygdal attracted my attention as singularly regular in shape. On detaching it from the rock and examining it with the magnifying glass, I found it to be a coral, Favosites gothlandica. The fossil is nearly circular. Its greatest diameter is 17/10 in., its smallest diameter 15/10 in., its greatest thickness is 1/2 in. Notwithstanding the rubbing by exposure oa the shore, many of the ceils are quite distinct: the side attached to the trap is without cells. I found a second specimen of a similar coral in another part of the trap-rock. Of this the length is 1 in., the width 8/10. The exposed part is a section having the structure perfect; it is slightly weathered. The fossil is indissolubly united with the trap, its sharp septa penetrating it: the trap of the specimen is very compact.