The relative efficiency of two commercial live-traps for small mammals

Data obtained from live-trapping a population of field voles, Microtus agrestis, over a seven-month period was used to compare the trapping efficiencies of the Longworth and the Ugglan Mouse Special traps. The Ugglan Mouse Special is a cheaper alternative that is widely used in Scandinavia. Biases in the sex or age of captured animals were the same for both types of trap and the total numbers of captures were similar. There was no evidence that individual animals were more likely to be captured in the same type of trap at each capture session. We conclude that the Ugglan Mouse Special trap is a practical alternative to the Longworth trap for studies of small mammals by capture-mark-recapture techniques.     

A yardstick for measuring populations of small rodents

(1) Six-monthly trappings (summer and winter) were done between 1952 and 1969 of Wood mice (Apodemus sylvaticus) and Bank voles (Clethrionomys glareolus) in Wytham Woods, near Oxford. One hundred and fifty Longworth live traps were used on two 2-acre grids in oak-ash-sycamore woodland. (2) The traps were pre-baited for 48 hours and then set. The catch was examined on the evening of the same day and on the following morning. The total of animals caught during the 24 hours was used as an index to the actual numbers present. Animals retrapped in the morning (identified by a simple method of marking) were omitted from the total. (3) Between 1969 and 1972 the same procedure was used but trapping, evening and morning, was continued for 3-4more days until some 75–80% of the catch consisted of marked animals. (4) This enabled estimates to be made of the actual numbers of voles and mice present at each trapping and so to assess the proportion of the total present which was caught ring the first 24 hours. (5) These estimates were made by (Method la) a straight Lincoln Index, (Method lb) a Lincoln Index method as modified by Hayne (1949) and (Method 2) by Hayne's trap-out method. Over six trappings the estimates by these methods showed reasonable agreement. (6) Comparison of the index trapping (i.e. the numbers caught during the first 24 hours) with the estimates of the total numbers present showed that, on all occasions, more than half of the mice and voles present entered the traps during the first 24 hours. With Bank voles there was a tendency for about half of them to be trapped during this time during the winter and about three-quarters of them during the summer. (7) With Wood mice the figures are more variable but, again, never less than half were trapped during the first 24 hours and, on some occasions, nearly the whole of the population. (8) These results show that reasonably accurate estimates of the numbers of these rodents can be achieved within 3–4 days' trapping (estimates that can be cross-checked by different methods) by using a high density of traps (see (1) above). Furthermore, trapping for 24 hours only will always catch at least half of the population present and, on occasions, considerably more than half.     

The response of Culex quinquefasciatus (Diptera: culicidae) to traps baited with carbon dioxide, 1-octen-3-ol, acetone, butyric acid and human foot odour in Tanzania

The responses of Culex quinquefasciatus Say to traps baited with carbon dioxide, 1-octen-3-ol, acetone, butyric acid and human foot odour were studied in the field in Muheza, north-east Tanzania using Counterflow Geometry (CFG) and Centers for Disease Control (CDC) traps. It was found that significantly more C. quinquefasciatus responded to foot odour collected on nylon stockings than to clean nylon stockings (P < 0.05). Significantly more mosquitoes were caught in a CFG trap baited with carbon dioxide than in traps with either human foot odour, acetone or butyric acid. It was also found that in an outdoor situation a carbon dioxide baited CDC unlit trap collected over 12 times more C. quinquefasciatus than an unbaited CDC unlit trap and nine times more mosquitoes than CDC traps baited with 1-octen-3-ol alone (P < 0.05). The number of mosquitoes caught in a CDC trap baited with 1-octen-3-ol did not differ significantly from that of the unbaited CDC trap (P > 0.05). These results indicate that the Afrotropical C. quinquefasciatus respond significantly better to traps baited with carbon dioxide than to either octenol, acetone or butyric acid, and that human foot odour contains stimuli to which C. quinquefasciatus is attracted under field conditions.     

Effect of host odours on trap catch composition of Glossina pallidipes in Kenya

The effect of odour attractants on the composition of samples of Glossina pallidipes Austen was investigated by comparing the age and nutritional status of flies caught in unbaited biconical traps with those caught in traps baited with cow urine and acetone. For both male and female flies, baited traps caught more flies with significantly higher fat content than did unbaited traps. Thus the samples from baited traps were more representative of the population as a whole: males showed a fuller range of the fat/haematin conditions known to occur in the field and proportionately more females were in later stages of the pregnancy cycle, than from unbaited traps.     

Sampling demersal zooplankton: A comparison of field collections using three different emergence traps

Comparisons of demersal zooplankton collected in three structurally different emergence traps indicated that density and diversity estimates are affected by design features and sampling procedures. The smallest mesh netting (63 μm) in the walls of Hobson-Chess traps contained larger catches than traps with 202- or 333-μm mesh. Samples from Porter-Porter traps tethered 1 and 10 cm above the bottom had statistically more zooplankton than all other traps set on the substratum. A consistently greater total number of demersal zooplankton was captured in the Alldredge-King traps when all three trap types sampled at the same time and area. The abundance and rank order of all but the most numerous animals ( = harpacticoid copepods) differed between the traps. Alldredge-King traps caught more of the larger organisms (= polychaetes, cumaceans, and gammaridean amphipods), whereas, the Porter-Porter and Hobson-Chess traps contained larger densities of smaller zooplankton ( = copepod nauplii and gastropod veligers).     

Response of Trichogramma egg parasitoids to colored sticky traps

The response of Trichogramma spp. egg parasitoids to colored sticky traps was evaluated in the field during two seasons (1995/1996, 1996/1997). Traps consisted of a glass tube coated with Bird-Tanglefoot® into which colored paper was inserted or clear traps without paper. Colors tested were white, green, blue, yellow and red in the first season and white, green, yellow and black in the second season. The proportion of both female and male parasitoids caught on the sticky traps was significantly different among colors, indicating that the parasitoids actively move between plants and are not solely carried along passively by wind. White was the color most preferred by female parasitoids, followed by clear and green traps. Yellow was preferred over black but was less attractive than green. Visual cues may be used by Trichogramma spp. during the habitat location process. The color preference of male Trichogramma spp. differed significantly from females with yellow and green being more attractive than white. For all colors, more female Trichogramma spp. were caught on the sticky traps (>85% of all wasps caught), indicating a lower activity level and/or shorter lifespan for males. The use of white cylindrical sticky traps for monitoring Trichogramma spp. populations in the field is recommended.     

The influence of environmental management and animal shelters in vector control of Culicoides (Diptera,Ceratopogonidae) in northeastern Brazil

We investigated whether biting midges in peridomestic environments are affected by environmental management practices and the presence of domestic animals. We used CDC light traps to collect midges in 112 residences across 24 locations along tourism routes of Maranhão, Brazil. The collection areas were characterized as follows: i) peridomestic area with domestic animals and without management (dirty); ii) peridomestic with domestic animals and management (clean); iii) peridomestic without animals and with management (clean); iv) peridomestic without animals and without management (dirty). The first two treatments had higher biting midge species richness and abundance, respectively. Generalized linear models indicated a positive correlation between the presence of domestic animals and midge abundance, with an approximate four‐fold increase in Culicoides (Diptera: Ceratopogonidae) abundance in peridomestic areas with animals. The same model showed that domestic animals have no influence on richness. Environmental management does not appear to influence species richness or abundance of biting midges.     

Studies on the effectiveness of coroplast sticky traps for sampling stable flies (Diptera: Muscidae), including a comparison to Alsynite

Stable flies, Stomoxys calcitrans (L.) (Diptera: Muscidae), are a blood-feeding pest of cattle worldwide. A new trapping material, Coroplast, was compared with Alsynite sticky traps based on the number, sex, and parity of stable flies caught. Coroplast sticky traps caught more stable flies than Alsynite (trap catches of 2384 versus 753 on 15 traps), with this increase attributed to catching more males (1531 versus 532) and nulliparous females (817 versus 175); parous catches were similar (36 versus 46). The spectral reflectance of Alsynite and Coroplast sticky traps is reported. We also examine Coroplast traps in detail with respect to trap color. Although clean sheets of Alsynite had a higher solar reflectance than Coroplast (90 versus 82% at 450 nm), Coroplast with debris had a higher reflectance than debris-covered Alsynite (62 versus 30% at 450 nm). White Coroplast was most effective, followed by closely by gray. Black and blue were the least effective trapping colors.     

Influence of pitfall versus Longworth livetraps, bait addition, and drift fences on trap success and mortality of shrews

Pitfall trapping is believed to be the most efficient method for capturing shrews (Sorex spp.); however, Longworth live-traps have been used successfully in North America and Great Britain. Due to high metabolic rates, previous attempts to livetrap shrews have been faced with very high (exceeding 95 % in some circumstances) mortality rates. Here we report the results of two experiments attempting to integrate successful livetrapping of shrews into standard rodent trapping protocols. In Experiment 1 we compared efficiency of pitfall and Longworth live-traps operated with drift fences on 1-ha trapping grids for capturing vagrant shrews (Sorex vagrans) on agricultural set-asides in Delta, British Columbia, Canada. A total of 100 trap stations, on each of three trapping grids, were equipped with a 3-m-long drift fence and randomly assigned either one pitfall at the centre of each fence, or two Longworth traps, one at each end of the fence. In addition, we randomly selected 50 % of trap stations and provided 6 g of mealworms (Tenebrio molitor) larvae as bait. In response to high mortality rates, we varied the frequency of trap checks, with intervals of 12–14 h (long), 6–9 h (medium) and 3–4 h (short). Contrary to our predictions, Longworth traps captured significantly more shrews than pitfall traps. We observed the highest mean mortality rates in traps without mealworms, checked at long intervals. Shrews in mealworm-baited traps checked at short intervals experienced no mortality. Mortality rates in mealworm-baited traps checked at short and medium intervals were similar (t?=??1.33, P?=?0.20, Bonferroni-corrected alpha?=?0.004). In Experiment 2, we attempted to determine the relative gains in efficiency when using drift fences in conjunction with Longworth and pitfall traps. However, due to small sample size, we were unable to detect significant differences. A trapping protocol using Longworth traps in conjunction with drift fences, provided with mealworms as food, and checked at a maximum interval of 8 h should be sufficient to effectively include shrews in rodent livetrapping studies.     

Aphis migration and the efficiency of the trapping method

Reproducible results were obtained when adhesive traps for aphides were placed at the same height in different parts of a potato field. The total catches in different localities in different seasons can therefore justifiably be compared. During the summer dispersal flights, different species flew at different heights, so traps at one height only are not suitable for comparing the relative abundance of different species. There was less variation in numbers caught on traps at 3–4 ft. above the ground than on traps at 5–6 ft. or at ground-level.
During the first fortnight of July an average of 200 aphides, 1.6% of which were Myzus persicae , was caught on traps in the position of potato plants. Most of these were not potato aphides, but it is suggested that some of them might act as vectors of potato viruses. The number of aphides caught was roughly proportional to the volume of free air space around the traps, and as the foliage increased in density the numbers caught on lower traps decreased in proportion.
Wind-speed records within and above the crop are discussed and it is shown that conditions are often suitable for voluntary aphis flight in and near the crop on relatively windy days. Records of catches on the half-traps facing the wind and on the other halves showed that voluntary flight decreased with increasing height.
Brilliant yellow traps, coated with adhesive grease, caught more aphides than white traps, which in turn caught more than black.     

Behaviour of male European corn borer, Ostrinia nubilalis Hübner (Lep.; Crambidae) towards pheromone-baited delta traps, bucket traps and wire mesh cone traps

Abstract:  Pheromone-baited traps are used to monitor the flight of European corn borer (ECB; Ostrinia nubilalis ). Traps of various designs are available: bucket traps, delta sticky traps and wire mesh cone traps. However, these traps are not all equally efficient and little is known about the reasons for this difference in efficiency. We investigated the behaviour of ECB males towards bucket traps and delta traps by means of observation in a wind tunnel. We also carried out observations and capture trials with delta traps and wire mesh cone traps in field conditions. Our laboratory studies showed that ECB males were not optimally attracted and were poorly captured by a pheromone baited bucket trap. Furthermore, they were shown to readily enter delta traps in the wind tunnel but were caught after more than three passages through this trap. Field studies showed that wire mesh cone traps captured approximately six times more ECB males than delta traps. Observation of the behaviour of ECB males showed that this difference was due to more efficient moth capture rather than greater attraction of the moth. In total, 31.5% of the 219 males observed close to wire mesh cone traps were caught, vs. 2.5% of the 520 males observed close to delta traps. This greater efficiency is due to a better capture rate of the attracted males by wire mesh cone traps than by delta traps.     

Comparison of trap designs for use with aggregation pheromone and synthetic co-attractant in a user-friendly attract and kill system to control Carpophilus spp. (Coleoptera: Nitidulidae)

Abstract  Three field experiments were conducted in stone fruit orchards in the Goulburn Valley, northern Victoria, Australia to identify a user-friendly trap for use in attract and kill stations for control of Carpophilus spp. (Coleoptera: Nitidulidae). A funnel trap design was compared with two types of delta trap in one experiment and two types of Lucitrap in another experiment. All traps were baited with synthetic co-attractant and synthetic pheromone. The funnel trap was the most effective type of trap tested. The funnel traps caught significantly more beetles than either the delta traps with bio-attractant or delta traps wrapped with insecticide impregnated banana wrap. No difference was observed between catches in either delta trap design. Lucitraps without covers caught significantly more beetles than Lucitraps with covers but funnel traps caught significantly more beetles than either type of Lucitrap. Beetle numbers caught in the funnel traps were three to five times higher than in Lucitrap. The use of funnel traps in attract and kill stations to protect stone fruit crops by suppressing the Carpophilus spp. population gave superior control to 'grower normal practice of spraying insecticides' both in terms of Carpophilus spp. numbers and in terms of reduction in percentage of fruit damaged.     

Development of a host-based semiochemical lure for trapping emerald ash borer Agrilus planipennis (Coleoptera: Buprestidae)

Bark volatiles from green ash Fraxinus pennsylvanica were tested for electrophysiological activity by Agrilus planipennis using gas chromatographic-electroantennographic detection (GC-EAD) and for behavioral activity using baited purple traps in Michigan. GC-EAD analysis of the headspace volatiles of bark tissue samples from 0- and 24-h-old fully girdled (stressed) ash trees showed that the latter had elevated sesquiterpene levels. Six of the elevated compounds consistently elicited antennal responses by both male and female A. planipennis. Five of the antennally active compounds were identified as alpha-cubebene, alpha-copaene, 7-epi-sesquithujene, trans-beta-caryophyllene, and alpha-humulene (alpha-caryophyllene). The sixth EAD-active compound remains unidentified. We monitored capture of adult A. planipennis on traps baited with several combinations of ash tree volatiles. Treatments included two natural oil distillates (Manuka and Phoebe oil) that were found to contain, respectively, high concentrations of four and five of the six antennally active ash bark volatiles. A four-component leaf lure developed by the USDA Forest Service and Canadian Forest Service was also tested. In three separate field studies, Manuka oil-baited traps caught significantly more adult beetles than unbaited traps. Lures designed to release 5, 50, and 500 mg of Manuka oil per day all caught more insects than unbaited traps. In a field test comparing and combining Phoebe oil with Manuka oil, Phoebe oil-baited traps caught significantly more beetles than either Manuka oil-baited traps or unbaited traps. We hypothesize that the improved attractancy of Phoebe oil to A. planipennis over Manuka oil is caused by the presence of the antennally active sesquiterpene, 7-epi-sesquithujene.     

Studies on the effects of bait and sampling intensity on trapping and estimating Wood mice, Apodemus sylvaticus

The effects of baiting a Longworth trap with whole oats and the density of traps on an area, or sampling intensity, on trapping and estimating Wood mice were studied on two neighbouring woodland plots in November 1971. Standard capture-mark-recapture (CMR) methods were used for two weeks followed by five nights of removal trapping.
The presence of bait significantly increased the likelihood of capturing marked and unmarked animals. By increasing the sampling intensity a greater proportion of the population was sampled, although the number of animals captured per trap night decreased. These results have been related to the "effective" number of traps on an area.
Observations on population structure, weather, movement and capturing marked and unmarked animals have been made. CMR population estimates closely resembled the cumulative number of individuals captured in each study and were for the main part lower than the estimates from the removal trapping carried out at the end of the studies.     

Preference of the cabbage root fly, Delia radicum (L.), for coloured traps: influence of sex and physiological status of the flies, trap background and experimental design

Abstract. Catches of Delia rudicum (L.) (Diptera: Anthomyiidae) were compared in water traps that reflected predominantly wavelengths shorter (violet and blue traps) and longer (green and yellow traps) than 500 nm.Traps were positioned in choice and no-choice situations against backgrounds of bare soil and weeds in the field and against backgrounds of brown and green paper in the laboratory.The physiological status of the flies was modified in the laboratory by denying them access to food sources and oviposition sites.
Males discriminated significantly more clearly than females between yellow and blue traps.The discrimination between yellow and blue traps was significantly more pronounced when the traps were presented in the choice than in the no-choice situation in both sexes.Green background (weeds and green paper) was highly preferred for landing and thus competed with the traps to such an extent that few flies were caught when non-preferred violet and blue traps were sited on green backgrounds.Flies seldom landed on the brown background (soil and brown paper) which resulted in the relative increase of catches in the non-preferred violet and blue traps.The preference for yellow traps was innate even in young flies with immature egg-follicles.Females that were ready to lay eggs, even those deprived of an oviposition site till the age of 8 days, also preferred yellow traps.In the no-choice situation, flies deprived of food landed with the same frequency in yellow and blue traps.Food deprivation, however, did not affect preference for yellow traps over the blue traps presented in a choice situation.     

Influence of sticky trap color and height above ground on capture of alate Elatobium abietinum (Hemiptera: Aphididae) in Sitka spruce plantations

A series of field trials were used to assess the practicality of using sticky traps to monitor populations of green spruce aphid, Elatobium abietinum (Walker), in plantations of Sitka spruce. The highest numbers of alate E. abietinum were caught on sticky traps placed in the upper third of the live canopy at 9-17 m above the ground, whereas low numbers of aphids were caught just below the live canopy or at 2 m above the ground. Trials in 2005 with sticky traps of different colors showed that significantly more alate E. abietinum were caught on yellow, red, and green sticky traps than on white, blue, and black traps. A repeat trial in 2007 resulted in significantly more alate aphids being caught on red sticky traps than on traps of any other color except for green. Attraction to red is unusual among aphids, as aphids are thought not to possess a red-sensitive photoreceptor. The attraction of E. abietinum to red-colored sticky traps suggests that conifer-feeding aphids might have a fundamentally different color response compared with aphids that live on cereals, grasses, or herbaceous plants. Alternatively, the attraction to red might be a physiological artifact related to the presence of red-screening pigments in the aphid's compound eye.     

Reasons for arboreality in wood mice Apodemus sylvaticus and Bank voles Myodes glareolus

Although it is broadly accepted that small mammals often climb trees, only few studies explore arboreality in woodland rodents systematically. Here, we investigate the three-dimensional habitat use of wood mice Apodemus sylvaticus and bank voles Myodes glareolus at three different sites in Wytham Woods, Oxfordshire, under varying environmental conditions. A total of 12 trapping sessions was carried out between March and September 2003 and 2004. During each session, 100 Longworth live-traps with shrew escape holes were set in a 25-point-grid for 3 succeeding nights. Each time, 50 traps were placed on the ground, and 50 in surrounding trees at heights of 30–250 cm. Wood mice were significantly more arboreal than bank voles, and male wood mice spent significantly more time in trees than did females. Arboreality in bank voles occurred only under high population densities and food shortage, and both species were significantly more arboreal in woodland with dense understorey. Thus we conclude that while arboreality is predominantly a result of inter- and intra-specific competition, of the two species we studied, only wood mice, being more agile, can afford to utilize trees without getting caught by predators, and that sex differences are due to male territoriality. Estimates of population sizes and distribution, as well as studies of inter-specific interactions and socio-spatial behaviour are presumed to be affected by these results, and are currently likely to underestimate rodent numbers considerably.     

Evaluation of monitoring traps for Drosophila suzukii (Diptera: Drosophilidae) in North America

Drosophila suzukii Matsumura (Diptera: Drosophilidae), a recent invasive pest of small and stone fruits, has been detected in more than half of the U.S. states, and in Canada, Mexico, and Europe. Upon discovery, several different trap designs were recommended for monitoring. This study compared the trap designs across seven states/provinces in North America and nine crop types. Between May and November 2011, we compared a clear cup with 10 side holes (clear); a commercial trap with two side holes (commercial); a Rubbermaid container with mesh lid and rain tent (Haviland), and with 10 side holes and no tent (modified Haviland); a red cup with 10 side holes (red); and a white container with mesh lid and rain tent (Van Steenwyk). Although fly catches among traps varied per site, overall, the Haviland trap caught the most D. suzukii, followed by the red, Van Steenwyk, and clear trap. The modified Haviland and commercial trap had low captures. Among five crop types in Oregon, a clear cup with mesh sides (Dreves) also was tested and caught the most flies. Traps with greater entry areas, found in mesh traps, caught more flies than traps with smaller entry areas. In terms of sensitivity and selectivity, traps that caught more flies likewise caught flies earlier, and all traps caught 26-31% D. suzukii out of the total Drosophila captured. Future trap improvements should incorporate more entry points and focus on selective baits to improve efficiency and selectivity with regard to the seasonal behavior of D. suzukii.     

Evaluation of yellow rectangle traps coated with hot melt pressure sensitive adhesive and sticky gel against Rhagoletis indifferens (Diptera: Tephritidae)

Sticky yellow rectangle traps have been used for many years to capture Rhagoletis (Diptera: Tephritidae) fruit flies. Traditional sticky yellow traps are coated with a sticky gel (SG) that can leave residues on the hands of users. An alternative to SG on traps are hot melt pressure sensitive adhesives (HMPSAs), which are less messy. The main objective here was to evaluate two rectangle traps of two yellow colors, the Alpha Scents Yellow Card coated with HMPSA (Alpha Scents, West Linn, OR), and the Pherocon AM trap coated with SG (Pherocon; Trécé, Adair, OK), for capturing western cherry fruit fly, Rhagoletis indifferens Curran. Flies captured on both traps and held in the laboratory and field did not escape their surfaces. Flies caught on HMPSA were damaged when removed from traps without citrus solvent, whereas flies caught on SG could be removed intact without solvent. In field tests, Alpha Scents traps baited with an ammonium bicarbonate lure captured 1.4-2.2 times more R. indifferens than Pherocon traps baited with the same lure. Results of an experiment that eliminated differences in surface sticky material type, overall size, and surface sticky area between Alpha Scents and Pherocon traps suggested, although did not show conclusively, that more flies were caught on the Alpha Scents than Pherocon traps because of their different yellow color and/or lower fluorescence and not the HMPSA. Overall, the Alpha Scents trap is a viable alternative to the Pherocon trap for detecting R. indifferens.     

The effects of pitfall trap diameter on ant species richness (Hymenoptera: Formicidae) and species composition of the catch in a semi-arid eucalypt woodland

Abstract Ants play an important role in Australian biodiversity and environmental impact assessments, with pitfall-trapping being the principal sampling method. However, the relationship between trap diameter and ant species catch has not been investigated in the context of survey design. Using four different trap diameters, each at a density of one trap per 100 m2, the present study asks three questions: (i) given an equal number of traps, do traps with larger diameters catch more species than smaller-diameter traps?; (ii) do traps with small diameters bias against large or rare species?; (iii) for equal area of the trap mouth, do small but more numerous traps catch more species than fewer but large traps? A total of 84 species were sampled within the 1600 m2 study site, with numbers of species for trap diameters of: 18mm (46 species), 42mm (56 species), 86mm (62 species) and 135mm (64 species). At equal trap density, 18 mm traps caught significantly fewer species than larger traps. Traps of 86 mm and 135mm were no more efficient than 42mm traps. Only 86mm and 135mm traps caught all species > 10mm in length (6 species). For equal area of the trap mouth, small traps were more efficient than large traps. Differences in the catch of the different-sized traps were due primarily to different capture rates of the rare species (40 species): 18mm traps caught 25% of rare species, 42 mm caught 41%, 86 mm caught 44% and 135 mm caught 52%. The role of rare ant species in environmental impact studies is discussed.