Methods for monitoring outdoor populations of house flies, Musca domestica L. (Diptera: Muscidae).

Relative collections of house flies were compared on two Florida dairy farms using several monitoring methods: sticky cylinders, baited jug traps (Farnam Terminator and Victor Fly Magnet), and bait strips (Wellmark QuikStrike). Bait strips were placed over collecting pans and under 61 cm square plywood roofs to protect the toxicant from sunlight ("sheltered QuikStrike traps"). Sticky cylinders collected the fewest flies (515-679 flies/trap/day) and sheltered QuikStrike traps the most (5,659-8,814 flies/trap/day). The sheltered QuikStrike traps are promising tools for disease surveillance programs. The two baited jugs collected a similar and intermediate number of flies, with collections highest during the first 2 days after placement (2,920-5,462 flies/trap/day). Jug trap collections were low after 4 days of use in the field, apparently due to deterioration in the attractiveness of the bait over time. Jug traps collected mostly females, whereas sticky cylinders and sheltered QuikStrike traps collected mostly males. Exposure of jug trap bait (Farnam) to fly cadavers for 3 days did not increase attractiveness of the bait. Combinations of the Farnam and Victor attractants were more attractive than either attractant alone and 25-43% more attractive than expected based on the sum of collections in the single-attractant jug traps. A 25% solution of farm-grade blackstrap molasses was as effective as either of the two proprietary baits tested, offering a low-cost alternative for fly population monitoring.     

The role of competition by dominants and temperature in the foraging of subordinate species in Mediterranean ant communities

In this paper we test the influence of temperature and interference competition by dominant species on the foraging of subordinate species in Mediterranean ant communities. We have analyzed the changes in resource use by subordinate species in plots with different abundances of dominant ants, and in different periods of the day and the year, i.e., at different temperatures. The expected effects of competition by dominant species on foraging of subordinates were only detected for two species in the number of baits occupied per day, and for one species in the number of foragers at pitfall traps. In all three cases, subordinate species were less represented at baits or in traps in plots with a high density of dominants than in plots with a medium or low density of dominants. The number of workers per bait, and the foraging efficiency of subordinate species did not differ in plots differing in dominant abundance. Daily activity rhythms and curves of temperature versus foraging activity of subordinate species were also similar in plots with different abundance of dominant species, indicating no effect of dominants on the foraging times of subordinates. Instead, temperature had a considerable effect on the foraging of subordinate species. A significant relationship was found between maximum daily temperature and several variables related to foraging (the number of foragers at pitfall traps, the number of baits occupied per day, and the number of workers per bait) of a number subordinate species, both in summer and autumn. These results suggest that the foraging of subordinate ant species in open Mediterranean habitats is influenced more by temperature than by competition of dominants, although an effect of dominants on subordinates has been shown in a few cases. In ant communities living in these severe and variable environments, thermal tolerance reduces the importance of competition, and the mutual exclusion usually found between dominant and subordinate species appears to be the result of physiological specialization to different temperature ranges. Received: 8 May 1998 / Accepted: 30 July 1998     

Carbohydrate bait preferences of wasps (Vespula vulgaris and V. germanica) (Hymenoptera: Vespidae) in New Zealand

Abstract

Carbohydrates are both a source of food and a potential bait for control of common and German wasps. Carbohydrate preferences of wasps were determined in a series of paired trials by counting the number of wasps caught in traps baited with carbohydrate‐based baits versus a standard protein‐based bait. Factors influencing wasp attraction to carbohydrate‐based baits included bait type, season, weather, and location. A 30% sucrose solution was more attractive than honey, jams, gels, or dry (solid) sugars. The sucrose solution was more attractive in spring and autumn than in summer, probably because rainfall washed away natural carbohydrate supplies. There was a significant relationship between rainfall in the previous week and the proportion of wasps caught in traps baited with sucrose solution versus sardine cat‐food. A higher proportion of German wasps than common wasps was caught in sucrose‐baited traps. This may have been related to seasonal differences in abundance and/or behavioural differences between the two species. In some locations, more wasps were caught in traps baited with sucrose solution than in those baited with sardine cat‐food. The proportion of wasps caught in sucrose‐baited traps was higher in locations without beech scale honeydew than with beech scale honey‐dew. Proportionally more non‐target species (mainly honey bees) and fewer wasps were caught in traps baited with sucrose solution than in those baited with sardine cat‐food. All five bee repellents tested also repelled wasps. These results indicate the importance of determining the bait preferences of wasps (carbohydrate or protein) and the presence of non‐target species before attempting a poison‐baiting operation. They also emphasise the need for a wasp‐specific carbohydrate‐based bait.     

Attractiveness of baits to dung beetles in Brazilian savanna and exotic pasturelands

The Brazilian savanna is the second largest ecosystem in Brazil. It is also one of the most endangered, with only 20% of its habitat remaining unchanged. Agriculture and livestock have been indicated as the main agents of destruction of the Brazilian savanna. Brazilian livestock, for example, is the main reason for cultivation of exotic grasses such as Urochloa spp. (from Africa). Dung beetles are widely used in ecological assessment, mainly because they are recognized as bioindicators of environmental changes. Therefore, efficient sampling is required for any research involving the biodiversity of this group. In order to mitigate the lack of information on efficiency of the attractiveness of baits in the endangered Brazilian savanna and in exotic pasturelands, we sampled dung beetles in four native patches of the Brazilian savanna and in four areas of pastures with Urochloa spp. Dung beetles were captured with pitfall traps baited with carcass, cattle dung, human feces and pig dung, with a total sampling effort of 384 traps. We sampled 7544 individuals belonging to 43 species and 18 genera of dung beetles. Thirty‐eight species were collected in the Brazilian savanna and 24 species in exotic pastureland. In both ecosystems traps baited with human feces sampled greater abundance and species richness of dung beetles when compared with the other three baits used. Our results showed that human feces is a reliable, easy and inexpensive bait to sample greater abundance and species richness of generalist dung beetles in both native and exotic habitats, with clear structural differences.     

Invasive Snake Activity Before and After Automated Aerial Baiting

Aerially delivered toxic baits have proven effective for landscape-level control of numerous invasive vertebrate populations with major benefits for conservation and ecosystem function, but this technique has not been broadly adapted for control of invasive reptiles. Nonnative brown treesnakes (Boiga irregularis) on the Pacific island of Guam have caused severe ecological and economic damage and pose an invasion risk on other islands, making them a high-profile candidate for application of aerial baiting methods. Although terrestrial applications of traps, toxicants, and hand-removal are standard brown treesnake management practices, these methods are not cost-effective for control in the island's large tracts of remote, rugged forest. In 2016, the first major in situ evaluation of a helicopter-borne automated aerial bait delivery system applied snake-targeted toxic baits at an effective rate of approximately 120 baits/ha over a 110-ha forested test plot on Guam. We evaluated the extent and duration of the suppressive effect of this toxic bait application on brown treesnakes by measuring nontoxic bait take rates as a proxy index of relative snake abundance before and after toxic bait application in a treatment plot and surrounding reference area. We placed 4,420 nontoxic baits in random transects at georeferenced locations, from 1 month before until nearly 12 months after toxic bait application, allowing temporal analysis of the suppressive effect and spatial analysis of treatment plot reinvasion. Over the first 30 days after toxic bait application, average nontoxic bait take rate in the treatment plot was 41.2% lower than the pre-application rate, and there was no immediate decrease in bait take in the reference area. Reduced snake activity was still evident nearly 12 months after bait application. Roads forming a portion of the treatment boundary appeared to slow snake movement between treated area and surrounding untreated area. Trail cameras monitoring a subset of bait tubes showed that 97.5% of baits removed were taken by snakes rather than nontarget species. We indexed rodent abundance in the treatment plot and reference area, and found no indication of a rodent population increase following toxic bait application. Our results show that automated aerial bait applications can suppress brown treesnake abundance over a large area and that reinvasion from surrounding untreated habitat occurs over several months. We anticipate that repeated bait applications could achieve and maintain greatly reduced brown treesnake abundance on a landscape scale, potentially improving biosecurity and enabling experimental reintroduction of native birds extirpated by brown treesnake predation. Published 2019. This article is a U.S. Government work and is in the public domain in the USA. The Journal of Wildlife Management published by Wiley Periodicals, Inc. on behalf of The Wildlife Society.     

Use of Rhodamine B to Reveal Patterns of Interspecific Competition and Bait Acceptance in Raccoons

Abstract: Passive treatment of raccoons (Procyon lotor) through distribution of vaccine-laden baits recently has emerged as a potential solution to address health and economic conflicts associated with raccoon rabies and may have applications in the management of other pathogens carried by raccoons if frequent bait deployments are used. Consumption of baits by nontarget species reduces the efficiency in which baits can be used to manage wildlife disease, although no study has explicitly evaluated the influence of bait competitor density on the ability to treat raccoons. Our objectives were to use the biomarker Rhodamine B (RB) to 1) evaluate patterns of raccoon bait acceptance as a function of competition with Virginia opossums (Didelphis virginiana), the dominant bait competitor; 2) characterize attributes of opossum bait acceptance to improve efficiency of raccoon treatment; and 3) evaluate the effect of repeated bait exposure on rates of bait acceptance as may be required in the management of wildlife disease issues beyond rabies. Identifying bait consumption by individuals based on the presence of an RB mark in a sample of whiskers, we used logistic regression to model raccoon and opossum bait acceptance as a function of bait availability, previous exposure to baits, demographic attributes, and an index of time spent in the baited area (residency index). For both raccoons and opossums, the best measure of bait availability was the variable number of baits per opossum. The most parsimonious logistic regression model for raccoon bait acceptance included the variables baits per opossum, exposure history, and residency index. The strength of the variable baits per opossum relative to competing measures of bait availability indicated bait consumption by opossums significantly limited the ability to treat raccoons. The most parsimonious model for opossum acceptance was composed of the variables baits per opossum, sex, weight, residency index, baits per opossum X sex, and weight X sex. Patterns of opossum bait acceptance likely were driven by effects of bait availability and sex-dependent differences in movement. Our results call attention to the importance of bait competition in limiting the ability to effectively treat raccoon populations through distribution of baits and suggest managers incorporate information on density of bait competitors, particularly opossums, in allocation of baits.     

Predicting bait uptake by feral cats,Felis catus,in semi‐arid environments

Feral cat control using aerial broadcasting of toxic baits continues to be used in the rangelands of Western Australia. The effectiveness of these operations has sometimes been compromised by different environmental factors that affect prey and cat numbers. This study demonstrates that the ratio of cats to their preferred prey (small mammals) can be used to predict the most effective time to bait. The regular baiting of three conservation sites offered an opportunity to study the relationship between feral cat abundance, the abundance of their prey and ingestion of toxic baits. Peron Peninsula on the mid‐west coast, Lorna Glen station in the northern Goldfields and the central Gibson Desert of Western Australia are sites where cat control using toxic baits has been routinely applied over the last 15 years. We postulated that bait ingestion by cats was linked to the availability of live prey. Small mammal abundance (capture rates in pit‐fall traps) and relative cat abundance (based on daily track counts) were assessed at these sites and the data used to produce a predator‐prey ratio index (PPRI). We used generalised linear mixed models to test the effect of prey abundance, prebaiting cat abundance and PPRI on baiting efficacy (BE). The best model for predicting efficacy of baiting contained only PPRI. This simple model was able to predict baiting success over the entire range of outcomes, from highly successful ( >75% cat reduction) to unsuccessful (0% cat reduction). The ability to predict feral cat BE in advance of planned toxic baiting operations will provide a valuable tool for wildlife managers involved in cat control.     

Efficiency of volatile baited sticky traps for the Tarnished Plant Bug (Lygus lineolaris) in strawberry fields

Insecticides have adverse effects on human health and the environment. Thus, the development of non-chemical replacement to manage insect pests is urgent. An alternative is to bait sticky traps with attractive insect sex pheromones or plant volatiles. In Quebec, the tarnished plant bug (Lygus lineolaris) is a major insect pest. We tested the efficiency of sex pheromones (mixture of hexyl butyrate (HB), (E)-2-hexenyl butyrate (E2HB) and (E)-4-oxo-2-hexenal (KA)) and sunflower (Helianthus annuus) volatiles (pinene, sabinene and phenylacetaldehyde) as sticky trap baits for the tarnished plant bug in strawberry fields of the Laurentians in Southern Québec, Canada. The pheromones decreased the number of tarnished plant bug caught in the traps compared to a control. The sunflower volatile did not have any effect on the number of individuals caught in the traps. Different Lygus species use HB, E2HB and KA in different ratios for sexual signals and alarm signals and for species recognition. GC-MS analysis of the sex pheromone bait revealed that the ratios between the three main compounds did not match the intended ratio for the L. lineolaris species. This mismatch probably explains our results. Individuals were not attracted to sunflower volatiles. Our results point to the difficulty of manufacturing and using sex pheromones as baits. Future work should assess the effect of several pheromone ratios.     

Interference between male‐targeted and female‐targeted lures of the Mediterranean fruit fly Ceratitis capitata (Dipt., Tephritidae) in Italy

The efficacy of male‐targeted and female‐targeted baits was compared when lures were presented together or singly in traps for capturing the Mediterranean fruit fly, Ceratitis capitata (Wiedemann). For male‐targeted baits, either trimedlure or ceralure presented singly attracted large numbers of flies, supporting data from many previous reports. The present results are the first published data on the attractiveness of ceralure to a European population of C. capitata. The quaternary female bait consisting of ammonium carbonate, putrescine, trimethylamine and acetic acid was a potent attractant for female flies (and also showed some activity for males). Replacing acetic acid with ammonium acetate in the quaternary female bait did not influence activity. Traps with female‐targeted and male‐targeted baits together always showed a tendency of catching fewer flies than traps with only one type of bait. The decrease was significant in females, regardless of whether ceralure or trimedlure was the male‐targeted bait. In males, the tendency was the same for traps with trimedlure or ceralure alone, catching higher numbers than those with both male and female baits. Our present results suggest that both types of baits mutually decrease the numbers of the non‐target sex in the trap. In conclusion, it is advisable to use both male‐ and female‐targeted baits in separate and distant traps and not jointly in the same trap, lest the efficacy of detection or monitoring trials be compromised.     

Influence of carrion smell and rebaiting time on the efficiency of pitfall traps to dung beetle sampling

Dung beetles (Coleoptera: Scarabaeidae: Scarabaeinae) are very useful insects, as they improve the chemo-physical properties of soil, clean pastures from dung pads, and help control symbovine flies associated with bovine cattle. Their importance makes it fundamental to sample and survey them adequately. The objectives of the present study were to determine the influence of decaying insects trapped in pitfalls on the attractiveness of Moura pig Sus scrofa L. (Suidae) and collared peccary Tayassu tajacu (L.) (Tayassuidae) dung used as baits to lure dung beetles, and to establish how long these baits remain attractive to dung beetles when used in these traps. Some dung beetle species seemed to be able to discriminate against foul smell from decaying insects within the first 24 h, hence decreasing trap efficiency. This was more evident in peccary dung-baited traps, which proved to be the least attractive bait. Attractiveness lasted only 24 h for peccary dung, after which it became unattractive, whereas the pig dung bait was highly attractive for 48 h, after which its attractiveness diminished but was not completely lost.     

Seasonal distribution and prevalence of dung beetles (Coleoptera: Scarabaeidae) in Kurukshetra,Northern India

A total of 8306 individuals as 29 species from 3 subfamilies (Hybosorinae, Aphodiinae, Scarabaeinae) were trapped by pitfall bait trapping. The maximum number of species of Scarabaeinae (68.97%) and number of individuals of Aphodiinae (56.84%) take part in the formation of a community. The number of species, number of individuals, diversity and dominance changes throughout the season. Seasonal prevalence of 82.76% of species and 50.81% of individuals was found in June. Aphodius campestris was found to be more attracted to the pitfall bait traps. The beetle community found in May shows the maximum Shannon's Diversity Index (2.46) but Margalef's Diversity Index was highest in August (3.06). Environmental factors play an important role in the occurrence and abundance of dung beetles. In the present study non-significant but positive correlations between temperature and species richness, abundance and diversity were found. Percent relative humidity showed a positive correlation with abundance only, and negative correlations with species richness and diversity.     

Do colours that deter birds affect cereal bait acceptance by possums (

Poisonous baits used for pest control in New Zealand commonly contain green dye and cinnamon oil to make them less attractive to birds. Research aimed at reducing the impact of poison based pest control on birds has shown that some birds are initially deterred from feeding on blue or, to a lesser extent, green coloured food and are attracted to yellow or red food. We determined whether colours that deter or attract birds affected the acceptance of non-toxic and toxic cereal baits by captive brushtail possums (Trichosurus vulpecula). Individual possums were offered, daily, a choice between a standard green dyed non-toxic cereal bait and either a blue dyed(17 possums) or yellow dyed non-toxic bait (16 possums) for 10 days. Following this, for the first group of 17 possums, 1080 toxin was added to either the green bait (9 possums) or blue bait (8 possums) and possums were offered the green versus blue choice again. Two additional groups that had not previously been fed cereal baits were also given a choice between blue and green baits, one of which was toxic. All possums offered non-toxic bait ate less on the first day of presentation than on subsequent days. There was no difference in acceptance of either blue or yellow coloured non-toxic bait compared to the standard green non- toxic bait on any days. Bait colour appeared to be unimportant in cereal bait choice and did not deter possums from eating any of the baits. The addition of toxin to baits did not significantly alter bait choice in any groups, although some individuals which had no previous experience with baits ate more toxic than non-toxic bait. These data suggest that adding a stronger bird deterring colour (i.e., blue) to poisonous baits is unlikely to adversely affect the acceptance of baits by possums.     

An assessment of re-randomization methods in bark beetle (Scolytidae) trapping bioassays

1 Numerous studies have explored the role of semiochemicals in the behaviour of bark beetles (Scolytidae). 2 Multiple‐funnel traps are often used to elucidate these behavioural responses. Sufficient sample sizes are obtained by using large numbers of traps to which treatments are randomly assigned once, or by frequent collection of trap catches and subsequent re‐randomization of treatments. 3 Recently, there has been some debate about the potential for trap contamination to occur when semiochemical treatments (baits), and not trap‐treatment units (traps and baits), are re‐randomized among existing traps. Due to the volatility of many semiochemicals, small levels of contamination could potentially confound results. 4 A literature survey was conducted to determine the frequency of re‐randomizing semiochemical treatments (baits) vs. trap‐treatment units (traps and baits) in scolytid trapping bioassays. An experiment was then conducted to determine whether differences in the response of Dendroctonus brevicomis LeConte to attractant‐baited traps exist between the two methods. 5 The majority of papers examined reported use of a large number of fixed replicates (traps) rather than re‐randomization of treatments at frequent intervals. Seventy‐five percent of papers for which re‐randomization methods could be determined reported relocation of semiochemical treatments (baits) only. 6 No significant differences in trap catch were observed among multiple‐funnel traps aged with D. brevcomis baits (Phero Tech Inc., Canada) for 0, 30 and 90 days, suggesting that contamination did not influence the results. 7 It is concluded that re‐randomizing baits is a viable cost‐effective option to re‐randomizing trap and bait units.     

Rye bread and synthetic bread odorants – effective trap bait and lure for German cockroaches

Bread‐in‐beer and bread‐in‐water are prevalent home recipe trap baits for attracting German cockroaches (GCRs), Blattella germanica (L.) (Dictyoptera: Blattellidae), which are significant urban pests. Our objectives were to (1) test the attractiveness of these baits, (2) study the underlying factors of GCR attraction, and (3) determine whether a blend of synthetic bread odorants could replace bread in a trap lure. In large‐arena laboratory experiments with laboratory‐reared GCR males, traps baited with rye bread not only captured eightfold more males than unbaited control traps but also most males released into bioassay arenas. Neither beer nor water enhanced the attractiveness of bread. Bread crust as a bait was more effective than bread crumbs. As Porapak Q headspace volatile extracts of rye bread attracted GCRs, all rye bread odorants in extracts were identified by gas chromatography‐mass spectrometry. Synthetic rye bread odorants and other known bread odorants were then assembled into a master blend. This master blend, and even partial blends lacking certain groups of organic volatiles such as aldehydes and ketones, proved very attractive to GCRs. We conclude that rye bread could be used as an effective bait in retainer traps or, laced with insecticide, as a food source in bait stations. A lure of synthetic bread odorants may eventually replace bread as bait, but the minimum number of essential odorants for that lure has yet to be determined.     

The effect of bait design on bait consumption in termites (Isoptera: Rhinotermitidae)

The efficacy of baiting as a pest control method relies on the bait appealing to the pest species. In the case of wood-eating termites, bait stations should be designed to encourage termite presence and to maximize their consumption of bait matrix in order to expedite control in minimal time. A field experiment examined the effect of bait size (one large bait or four small baits of equivalent total size, with commensurate inspection and replacement schedules), compaction (tightly rolled or loosely folded) and composition (paper only or paper plus wood) on termite presence and on untreated bait paper removal rates over four months. All three factors were significant, with bait size the most important factor, followed by compaction and then composition. The least effective baits were small, compacted (rolled) paper-only baits with monthly inspections; these had the highest abandonment rate (70%) and had the least paper removed (mean of 24 g). The most effective baits were large, folded paper-plus-wood baits with inspections at two months; these had the lowest abandonment rate (20%) and had the highest paper removal (mean of 112 g). The more than four-fold difference between these baits types demonstrates that bait efficacy can be altered considerably merely by changing bait design without adding new ingredients to the bait matrix.     

Translating Bait Preference to Capture Success of Northern White-Tailed Deer

ABSTRACT Wildlife management and research have depended upon trapping as an essential tool for decades. Although deer (Odocoileus spp.) capture by Clover traps remains a basic technique that has changed little over time, researchers use it as an integral part of field operations to support increasingly sophisticated and costly project objectives. Despite reports of deer preference for certain baits, no study has determined if bait preference can effectively increase capture success of free-ranging deer. By supplementing corn bait with salt, peanut butter, or molasses, we tested effects of these bait treatments on capture success of free-ranging white-tailed deer (O. virginianus), as well as levels of nontarget animal disturbance in Clover traps, during February-March 2005. With 1,446 adjusted trap-nights and a 6.5% capture success rate, the probability of capture increased over time and varied among 4 study sites (df = 3, P < 0.005); however, we did not detect a significant effect of bait supplementation on capture success (df = 3, P > 0.8). Nontarget animal activity in the trap varied by site (df = 3, P < 0.001), bait treatment (df = 3, P=0.04), and Julian date (df=3, P < 0.001). Our results are the first to suggest that bait preference may not translate into actual improved capture success of free-ranging deer. Future research should focus on testing additional baits or bait supplements to determine if an increase in trapping success and a minimization of trap disturbance by nontarget species occurs.     

Evaluating seasonal bait delivery to badgers using rhodamine B

In the UK and Ireland, research on the control of bovine tuberculosis in badgers includes the development of a palatable bait for oral delivery of a vaccine and a means of its deployment in the field. In the present study, we carried out field deployment of bait according to the established method of bait marking in early spring and early summer to compare the effects of seasonality on bait uptake rates. All baits contained rhodamine B (RhB) which was subsequently detected in the hair and whiskers of captured badgers. During the 8 days of bait feeding at 14 badger setts, 99% of baits deployed in spring, and 100% of those deployed in summer were removed. The presence of RhB in captured badgers indicated high rates of uptake amongst adult badgers in spring (93%) and summer (98%). Only cubs captured in summer showed evidence of having taken bait (91%). Between 67% and 100% of each social group was estimated to have taken bait. The detection of RhB in 96% of badgers captured at outlier setts, where bait was not fed, suggested that deployment at main setts alone may be sufficient to target a relatively high proportion of the badger population. The number of baits deployed per marked badger suggested that a similar level of uptake might be achievable using fewer baits. The results clearly demonstrate the potential value of the bait-marking methodology for delivering vaccine baits to badgers during spring and summer, but that deployment in early summer is necessary to target cubs.     

不同诱饵对搬运舞草种子蚂蚁诱集作用比较

在云南西双版纳和思茅地区有12种蚂蚁帮助舞草(Codariocalyx motorius)种子扩散。科学有效地监测蚂蚁种群的数量变化,对分析蚂蚁种群动态与舞草种群扩散的相互关系有重要的意义。作者采用陷阱诱捕法,用糖、鱼、肉、舞草种子做诱饵,并与不含诱饵的水(对照)及含3%甲醛的水溶液进行诱集蚂蚁的效果比较。结果显示搬运舞草种子的蚂蚁对不同诱饵的趋性及反应强度有明显差异。用糖、鱼、肉做诱饵与其它3种诱集方法相比,所诱集到的样地搬运和不搬运舞草种子的蚂蚁种类和数量要多。邻巨首蚁Pheidologeton affinisJerdon对糖和鱼有极强趋性,并影响诱集其他搬运舞草种子的。除邻巨首蚁外,通用的含3%甲醛溶液的诱集方法不影响诱集其他搬运舞草种子的蚂蚁,同时还能防止蚂蚁腐烂。搬运舞草种子的主要蚂蚁——伊大头蚁Pheidole yeensisForel对糖、鱼和肉均有趋性,对舞草种子也有一定的趋性。搬运舞草种子的蚂蚁在雨天的随机觅食活动很少,只有在食物的引诱下才出巢采食。试验结果表明,选择糖、鱼做诱饵不能完全反映搬运舞草种子的蚂蚁数量,而通用的含3%甲醛的水溶液是一种较好的监测方法,但诱集试验应避开雨天进行。     

Successful removal of German yellowjackets (Hymenoptera: Vespidae) by toxic baiting

Vespula germanica (F.) is a social vespid that has invaded many parts of the world, including Argentina. This wasp usually becomes a pest, affecting several economic activities. It also may impact the host community through predation or competition. The purpose of our study was to field test toxic baiting for reduction of wasp abundance. Wasps were poisoned with 0.1% fipronil mixed with raw minced beef in two beech forest sites on 20 February 2000 in northwestern Patagonia. All nests (46) within the two 6-ha sites with poisoned bait stations were killed, whereas Malaise traps in those sites captured 81.1% fewer wasps at the end of the season than traps in the two control sites. The average reduction of forager wasps on nontoxic baits was 87%. Fipronil was very effective in controlling wasp numbers, although there are limitations to the method, especially concerning conservation purposes. Toxic baiting can be useful in controlling wasp numbers in honey bee hive yards, farms, and parks.     

A comparison of pitfall traps with bait traps for studying leaf litter ant communities.

A comparison of pitfall traps with bait traps for sampling leaf litter ants was studied in oak-dominated mixed forests during 1995-1997. A total of 31,732 ants were collected from pitfall traps and 54,694 ants were collected from bait traps. They belonged to four subfamilies, 17 genera, and 32 species. Bait traps caught 29 species, whereas pitfall traps caught 31 species. Bait traps attracted one species not found in pitfall traps, but missed three of the species collected with pitfall traps. Collections from the two sampling methods showed differences in species richness, relative abundance, diversity, and species accumulation curves. Pitfall traps caught significantly more ant species per plot than did bait traps. The ant species diversity obtained from pitfall traps was higher than that from bait traps. Bait traps took a much longer time to complete an estimate of species richness than did pitfall traps. Little information was added to pitfall trapping results by the bait trapping method. The results suggested that the pitfall trapping method is superior to the bait trapping method for leaf litter ant studies. Species accumulation curves showed that sampling of 2,192+/-532 ants from six plots by pitfall traps provided a good estimation of ant species richness under the conditions of this study.