Presence Of Bait Research Articles

Effects of heterogenous forest environments on ground‐dwelling beetles in a conifer plantation

AbstractIt is widely recognized that heterogeneous environments promote biodiversity. Consequently, we investigated whether heterogeneous environments influence the diversity of ground‐dwelling beetles within a well‐managed conifer plantation forest. We collected carabid beetles, and necrophagous silphid and dung beetles (necrophagous beetles) using pitfall traps at 37 sites with or without fish meat bait. The result of a two‐dimensional principal component analysis (PCA) utilizing environmental indices measured at each site suggested that the environmental heterogeneity depended on the survival density of planted conifers, serving as an indicator of historical gap formation levels. Gaps populated by invading broadleaved trees exhibited low canopy opening percentages and understory cover degrees, while those filled by the growth of planted conifers displayed the opposite conditions. The presence of bait had a negligible impact on carabid beetles but significantly influenced necrophagous beetles. No significant relationships were found between the scores of PCA components and the beetle species richness, suggesting that a heterogeneous environment does not increase the beetle species diversities. However, significant relationships were observed with the scores on nonmetric multidimensional scaling axes, indicating that a heterogeneous environment contributes to the complexity of beetle assemblages. The most dominant carabid, Synuchus cycloderus, was abundant in areas where historical gap formation was thought to be more prevalent. Among necrophagous beetles, Pherotrupes laevistriatus and Panelus parvulus preferred habitats with darker environments, in contrast to Onthophagus fodiens and O. nitidus. This study will aid in developing forestry practices aimed at conserving specific ground‐dwelling beetle species within conifer plantations.

Influences of organic nitrogen on the removal of inorganic nitrogen from complicated marine aquaculture water by Marichromatium gracile YL28

The sediment-water interface is not only an important location for substrate conversion in a mariculture system, but also a major source of eutrophication. This study aimed to clarify the characteristics of inorganic nitrogen (ammonia, nitrite and nitrate) removal by Marichromatium gracile YL28 in the presence of both organic nitrogen and inorganic nitrogen. The results showed that, in the presence of peptone or urea, seaweed oligosaccharides (SOS) effectively enhanced the ammonia removal capacity of YL28 (6.42mmol/L) and decreased the residual rate by 54.04% or 8.17%, respectively. With increasing peptone or urea concentrations, the removal of both ammonia and nitrate was gradually inhibited, and the residual rates of ammonia and nitrate reached 22.56-34.36% and 12.03-15.64% in the peptone system and 20.65-24.03% and 12.20-13.21% in the urea system, respectively. However, in the control group the residual rates of ammonia and nitrate reached 11.97% and 5.12%, respectively. In addition, the concentrations of peptone and urea did not affect nitrite removal, and YL28 displayed better cell growth and nitrogen removal activity in the presence of bait and SOS. Overall, the ability of YL28 to remove inorganic nitrogen was enhanced in the presence of organic nitrogen.

SMART drumlines at Réunion Island do not attract bull sharks Carcharhinus leucas into nearshore waters: Evidence from acoustic monitoring

Following a series of shark attacks, local authorities in Reunion Island developed an experimental shark control programme using innovative fishing gear, namely Shark Management Alert in Real Time (SMART) drumlines (SDL). From January to November 2014, four SDL were deployed 24 h per day, four days per week to target bull (Carcharhinus leucas) and tiger (Galeocerdo cuvier) sharks and to test the fishing efficacy of the SDL. Presence and residence time of 19 acoustically tagged bull and 19 tiger sharks, which had been tagged up to two years before the SDL deployment, were modelled against different SDL configurations, which included bait type and presence of bait or catches on the hooks, as well as environmental parameters before, during and after SLD deployment. There was insufficient acoustic data from the tiger sharks for any analyses. Bull sharks spent less time in nearshore waters when drumlines were deployed, and their presence was influenced by sea surface temperatures (SST), rainfall and time of day. There was no difference in the number of bull sharks detected in the SDL deployment area compared with surrounding sites. As SDL catch rates were only poorly correlated with presence of tagged sharks, their efficacy in catching sharks present in the area could not be accurately determined. Overall, the results show that SDL, deployed without chum and baited with small, whole, low-fat fish cannot be considered as “shark magnets”, which could attract dangerous bull sharks inshore where they would pose a threat to the safety of surfers and other sea users. The detection of tagged bull sharks moving into and out of the SDL fishing area indicates that these fishing devices do not provide an impenetrable barrier to the passage of this potentially dangerous species.

PRACTICAL QUESTIONS FOR SILO BAGS GRAIN STORAGE TECHNOLOGY

In enterprises with limited capacities and a low-powered grain drying facilities there is a problem of economical and reliable storage of dry, wet and moist grains. One of the options for its successful solution is the application of grain storage technology in silo bags, tested in many enterprises, the basic principle of which is based on the self-preservation of grain under hermetic conditions in an environment of carbon dioxide. To implement this technology, it is necessary to determine the suitability of the batch of grain for loading in the silo bags on the basis of an operational analysis of the grain quality. After loading the grain, the silo bags are sealed, the grain mass is stored for a certain time and then unloaded. After many years of industrial testing of grain storage technology in silobags, recommendations have been developed that allow to ensure the quantity and proper quality of grain in the process of implementation of the technology. To do this, it is provided to carry out a whole range of activities - personnel training, the selection and preparation of a storage area for grain, deratization, the determination of the quality of grain at all stages and a safe shelf-life, depending on the condition of the grain, weighing of the grain; loading silo bags and placing them on the site; drawing of marks for identification of silobags; monitoring of the state of silo bags and grain and the restoration of the integrity of the silo bags throughout the storage period; accounting for grain in the silobags; processing of unconditioned grain; object protection, final analysis of the work performed, identify problems and ways to solve them. The storage site for grain in the silo bags must be cleaned of stubble and grass, sharp objects, grain residues, solid hardwood or the most densely packed soil (the clay surface is undesirable, as precipitation makes imposible laying and unloading of silobags), ensure no stagnation of water during rains and melting snow, provide the possibility of free movement of special equipment on the site. It must be deratized and fenced with a mesh with small openings, a height of at least 1 m and dipped. The analysis of the characteristics of three-layer silobags showed that to optimize the storage of dry grain, it is advisable to use the largest silobags of 90 m in length, since they have a larger capacity, there will be less time spent on dressing and sealing the silobags, saving space between the silo bags lying along one another , there will be less length of silobags to go for tying, as well as saving money on the cost of silobags, the cost of working time and fuel (decreases the number of transfers of special equipment). It is advisable to take into account the possibility of unloading the sleeve during one shift. At all stages (loading, storage, unloading) the determination of the quality of grain, monitoring the condition and restoring the integrity of the silo bags checking the sanitary condition of the site and the presence of baits should be carried out. Precautions should be observed, grain accounting, working with non-standard grain and final analysis of grain storage results should be carried out.

Survival of Mycobacterium bovis BCG oral vaccine during transit through a dynamic in vitro model simulating the upper gastrointestinal tract of badgers.

In developing an oral bait BCG vaccine against tuberculosis in badgers we wanted to understand the conditions of the gastrointestinal tract and their impact on vaccine viability. Conditions mimicking stomach and small-intestine caused substantial reduction in BCG viability. We performed in vivo experiments using a telemetric pH monitoring system and used the data to parameterise a dynamic in vitro system (TIM-1) of the stomach and small intestine. Some BCG died in the stomach compartment and through the duodenum and jejunum compartments. BCG survival in the stomach was greatest when bait was absent but by the time BCG reached the jejunum, BCG viability was not significantly affected by the presence of bait. Our data suggest that from a starting quantity of 2.85 ± 0.45 x 108 colony-forming units of BCG around 2 log10 may be killed before delivery to the intestinal lymphoid tissue. There are economic arguments for reducing the dose of BCG to vaccinate badgers orally. Our findings imply this could be achieved if we can protect BCG from the harsh environment of the stomach and duodenum. TIM-1 is a valuable, non-animal model with which to evaluate and optimise formulations to maximise BCG survival in the gastrointestinal tract.

Nocturnal and Sheltering Behaviours of the Desert Darkling Beetle,Pimelia senegalensis(Coleoptera: Tenebrionidae), in the Sahara Desert

Darkling beetles are representative insects in the Sahara Desert where the gregarization of the desert locust occurs. Although the abundance of darkling beetles is used as an environmental bioindicator after locust control operations with chemical pesticides, an appropriate sampling technique taking into account their behavioural characteristics has not been developed. The present study investigated the effects of environmental factors, including the presence of bait, light, air and ground surface temperature, as well as humidity, on diurnal activity and sheltering behaviour of the darkling beetle, Pimelia senegalensis Olivier in the Sahara Desert. We compared the effectiveness of baited and unbaited pitfall traps, in terms of numbers and timing of beetle captures. Few beetles were trapped before dusk, irrespective of the presence of bait. The beetles started moving around dusk. The baited pitfall traps were found to be more effective than unbaited ones. Field-collected adults previously maintained in shade were exposed to either direct sunlight or shade for 30 min every two hours from 08:00 to 20:00. High mortality was observed only for the unshaded specimens between 12:00 and 14:00, when the ground surface temperature rose above 50 °C. Observation of the diurnal sheltering behaviour using a pipe refuge showed that P. senegalensis tended to shelter inside the pipe during daytime, coming out only after dusk. These results suggested that baited pitfall traps deployed after dusk were effective for sampling the beetles, in accordance with the nocturnality and sheltering behaviours of P. senegalensis that allow them to avoid lethal ground surface temperatures.

Long-term partitioning of space between two territorial species of ants (Hymenoptera: Formicidae) and their effect on subordinate species

Competition is a major force organizing ant communities and results in co-occurring species evolving different strategies for foraging and use of space. Territorial species, as top dominants exclude each other, while shaping the local ant communities both qualitatively and quantitatively. In this study we examined how two territorial species, Formica polyctena and Lasius fuliginosus, can coexist in adjacent territories over long periods of time, and whether they affect co-occurring species of ants in different ways. Field observations in the absence and in the presence of baits were carried out around a L. fuliginosus nest complex surrounded by a polydomous F. polyctena colony in S Finland in 2007-2009. Both species controlled their territories, but were affected by changes in the abundance of the other species and the distance from L. fuliginosus' main nest. They did not have the same effect on the sub- ordinate species in the absence of baits, but the abundance of Myrmica spp. recorded at baits was negatively affected by both of the territorial species. The preferences of the different species for the artificial food sources differed: L. fuliginosus and F. polyctena pre- ferred tuna to honey and Myrmica spp. honey to tuna. More individuals of the subordinate species were recorded in the territory of F. polyctena than of L. fuliginosus, although conflicts with this territorial species were also recorded. During the three years of the study almost no overlaps in the territories of the two territorial species were recorded, and there were mostly minor shifts in the boundaries of the territories. Differences between the two territorial species in their use of space and competitive effects ensured their coexistence at this particular site in Finland.

Surface behaviour of bait-attracted white sharks at Dyer Island (South Africa)

Six research expeditions were conducted at Dyer Island to observe the surface behaviour of white sharks in the presence of bait. Observations were made from a commercial cage-diving boat. We observed 140 white sharks that exhibited 9 different types of behaviour: parading, bait following, visual inspection, breach, tail slap, tail stand, spy hop, repetitive aerial gaping, and head-up vertical emerging. Breach and tail slap were most often performed by male sharks, and tail slap and tail stand were more often performed by mature animals. The ethogram consisted of an average of 20 behavioural units, with a significant transitional pattern from bait follow to parading and from parading to bait follow. The individual surface behaviour of white sharks is not a simple stimulus–response reflex, but rather a complex tactical situation in which animals show plastic responses. Many aspects of white shark surface behaviour resemble those of other predator species that spend time at the surface.

Social interactions among bait-attracted white sharks at Dyer Island (South Africa)

The goal of this preliminary research was to provide an ethogram of social interactions among white sharks at Dyer Island's Nature Reserve (Gansbaai, South Africa) in the presence of bait. Eighty-three social interactions were observed, both from a boat and from a cage. Seven different interaction types were recognized: swim by; follow give way; follow; parallel swimming; give way; splash fights; and piggybacking. The preliminary data analysis did not reveal any significant relationship between the behavioural patterns and the sex of the sharks, but a strong correlation between behavioural patterns and the size of the animals was found. The observed displays were more often performed by animals of the same length than by animals of different size.

Activation of Protein Kinase Cζ Increases OAT1 (SLC22A6)- and OAT3 (SLC22A8)-mediated Transport

Organic anion transporters (OATs) play a pivotal role in the clearance of small organic anions by the kidney, yet little is known about how their activity is regulated. A yeast two-hybrid assay was used to identify putative OAT3-associated proteins in the kidney. Atypical protein kinase Czeta (PKCzeta) was shown to bind to OAT3. Binding was confirmed in immunoprecipitation assays. The OAT3/PKCzeta interaction was investigated in rodent renal cortical slices from fasted animals. Insulin, an upstream activator of PKCzeta, increased both OAT3-mediated uptake of estrone sulfate (ES) and PKCzeta activity. Both effects were abolished by a PKCzeta-specific pseudosubstrate inhibitor. Increased ES transport was not observed in renal slices from OAT3-null mice. Transport of the shared OAT1/OAT3 substrate, rho-aminohippurate, behaved similarly, except that stimulation was reduced, not abolished, in the OAT3-null mice. This suggested that OAT1 activity was also modified by PKCzeta, subsequently confirmed using an OAT1-specific substrate, adefovir. Inhibition of PKCzeta also blocked the increase in ES uptake seen in response to epidermal growth factor and to activation of protein kinase A. Thus, PKCzeta acted downstream of the epidermal growth factor to protein kinase A signaling pathway. Activation of transport was accompanied by an increase in V(max) and was blocked by microtubule disruption, indicating that activation may result from trafficking of OAT3 into the plasma membrane. These data demonstrate that PKCzeta activation up-regulates OAT1 and OAT3 function, and that protein-protein interactions play a central role controlling these two important renal drug transporters.

A two-chambered trap reduces within-trap predation by octopus on rock lobsters in aquarium trials

A two-chambered lobster trap was developed that in aquarium trials significantly ( p < 0.01) reduced octopus predation on trap-caught spiny lobster. The trap was designed using information gained from an investigation of the behavioural interactions of the maori octopus ( Octopus maorum) with traps used in the South Australian commercial lobster ( Jasus edwardsii) fishery. This study showed that octopuses were primarily attracted to traps by the presence of bait as opposed to lobsters and that octopus entry into traps was ‘fortuitous’ and mediated by speculative exploration. The outer chamber of the modified trap contained bait and allowed entry by octopuses but not lobster and the inner chamber allowed access to both animals. The trap worked on the principle that octopuses would enter the outer chamber containing bait via a side entrance in preference to entry to the inner chamber containing lobsters via the neck. This was found to be the case and lobster mortality was 70% lower in the two-chambered trap than a standard trap. Successful adaptation of this trap design to commercial fishing conditions could significantly reduce rates of octopus predation on rock lobsters in several important southern hemisphere fisheries for spiny lobsters.

Temporal patterns of change in the necrophagous hyperbenthic zooplankton community of Lobster Bay, Cape d'Aguilar Marine Reserve, Hong Kong

Crab-baited traps, with a 5-mm diameter opening, were deployed 90 mm off the seabed monthly at Lobster Bay, Hong Kong, for one year between 1998 and 1999. Visitors drawn to the traps were mainly species of Ceradocus (Gammaridea: Melitidae), Tisbe (Harpacticoida: Tisbidae) and Nebalia (Leptostraca: Nebaliacea). Apart from Ceradocus sp., all were scavengers with catches using baited traps significantly exceeding unbaited controls. Ceradocus sp. was apparently drawn to traps for refuge. The trapped scavenger community composition changed with deployment duration in the presence of bait. Nebalia sp., Neanthes cricognatha (Polychaeta: Nereidae) and Lepedepecreum sp. (Gammaridea: Lysianassoidea) were identified mostly two/three-days post-deployment, exhibiting a potential preference for rotten organic matter. Seasonal catches were also identified for all three visitors with maxima between October 1998 and April 1999. Such seasonal patterns might be related to either turbulence destabilizing the substratum during this period or life cycle patterns in the study area.

Development of a toxic bait for control of eastern lubber grasshopper (Orthoptera: Acrididae).

This study assessed baits for eastern lubber grasshopper, Romalea guttata (Houttuyn). When offered a choice among several grain-based baits (rolled oats, wheat bran, oat bran, yeast, corn meal, cornflakes) and vegetable oils (canola, corn, peanut, soybean), eastern lubber grasshopper adults preferred bait consisting of wheat bran carrier with corn oil as an added phagostimulant. Other carriers were accepted but consumed less frequently. Discrimination by eastern lubber grasshoppers among oils was poor. Similarly, addition of flavorings (peppermint, anise, lemon, banana) resulted in few significant effects. The carbaryl, wheat bran, and oil bait developed in this study was effective at causing eastern lubber grasshopper mortality in field-cage studies. Significant mortality occurred even though grasshoppers had to locate dishes of bait in a large cage, and could feed on daylilies, or grass growing through the bottom of the cage, rather than on the bran flakes. Consumption of as little as a single carbaryl-treated bran flake could induce mortality, although individuals varied greatly in their susceptibility. The bait matrix developed in this study was readily consumed when in the presence of some plant species. We expect that wheat bran and corn oil bait would be most effective as protection for less preferred plants (tomato, pepper, eggplant, leek, parsley, fennel, daylily, lily of the Nile, and canna lily) because baits were readily consumed in the presence of these plants. Plants that are readily consumed in the presence of bait (preferred plants) included butter crunch lettuce, carrot, yellow squash, cauliflower, collards, green onion, chive, cucumber, cabbage, cantalope, endive, red leaf lettuce, society garlic, caladium, and amaryllis. Baits are likely to be less effective in the presence of such plants. On average, vegetables in Solanaceae (i.e., tomato, pepper, and eggplant) and Apiaceae (i.e., fennel and parsley) elicited high levels of bait-feeding activity, indicating that these vegetables were not highly preferred. The plants tested from Liliaceae, Cucurbitaceae, Asteraceae, and Brassicaceae elicited an intermediate-to-low level of bait feeding.

Estimating Populations ofIdiarthron subquadratum(Orthoptera: Tettigoniidae) Using Mark-Recapture Methods in Coffee Plantations in Chiapas, Mexico

Idiarthron subquadratum (Orthoptera: Tettigoniidae) is a sporadic pest of coffee in parts of Mesoamerica. Mark-recapture techniques were employed to determine the adult population size in coffee plantations in the municipality of Siltepec, Chiapas, Mexico, where the insect has caused crop losses of around 50% over the past decade. Eight experimental blocks 50 by 50 m were deÞned in an area of 2,500 m 2 . A trapwas designed consisting of a bamboo tube 30 cm in length and closed at one end. Trials indicated that insect trapping efÞciency was not improved by the presence of baits. Traps placed above the ground in coffee bushes or as banana leaves placed on the side of an experimental gauze cage captured signiÞcantly more I. subquadratum individuals than traps placed on the ground. Tests with different types of paint combinations for marking insects revealed that nitrocellulose paint was durable, water-resistant and nontoxic to I. subquadratum. Mark-recapture experiments were performed at 48-h intervals over a 1-mo period. Concurrently, direct nocturnal observations of I. subquadratum individuals feeding on coffee leaves and berries were made on four occasions during the study period. The prevalence of I. subquadratum feeding damage was also quantiÞed at three sample dates during the study. JacksonOs negative and positive index, Fisher-Ford model, Lincoln-Petersen index, and Jolly-SeberOs stochastic model gave statistically similar mean population estimates. All of these mark-recapture models were also statistically similar to estimates generated by direct nocturnal counts of insects observed feeding on coffee bushes. In contrast, BaileyOs triple capture model gave a population estimate signiÞcantly lower than the other models. I. sub- quadratum feeding damage to coffee berries was signiÞcantly greater in blocks interplanted with banana. We conclude that mark-recapture methods combined with analysis using the Lincoln- Petersen model are simpler and less time consuming than direct nocturnal observations and give quantitatively similar population estimates.

Carbon disulfide effects on pre-baited vs. non-pre-baited rats exposed to low dosage zinc phosphide rodenticide bait

Control of rodents with rodenticides is frequently ineffective due to bait-shyness and neophobia. In an initial study, to increase bait acceptance, Wistar-strain laboratory rats were individually tested for attraction to 3 odors (rat urine, preputial gland extract, and carbon disulfide) and for repellence to a fourth odor (coyote urine) in a 2-compartment arena. Three measures of rat preference-amount of bait consumed, elapsed time to feeding, and time in each compartment suggested that carbon disulfide at 10 ppm was an attractant ( p=0.003). The other odors produced inconsistent results. In a second study, rats were offered pre-weighed quantities of USA Environmental Protection Agency (EPA) standard challenge bait containing a low level of 0.20% zinc phosphide (ZP) rodenticide. Two groups of rats ( n=28) were given either 0 or 3 days of pre-baiting prior to ZP bait exposure. Half the animals in each group received deionized water placebo odor and the others received the carbon disulfide odor in the presence of baits. EPA bait with carbon disulfide odor produced elevated consumption ( p=0.0099) with females showing a greater degree of effect ( p=0.046). Pre-baiting produced higher mortality (220%) and higher level ZP dosages (30%) during baiting. Although mortality was 11% higher in rats presented ZP bait with carbon disulfide, dosages were unchanged. Relative to pre-baiting, the attractant had a marginal effect on ZP bait acceptance and produced mortality changes in males only. Further development of controlled release of this attractant for rodenticide baits would be needed before field applications are attempted; implications for using attractants in baits, traps, tracking powders to optimally control both rat genders are discussed.

Diel activity patterns of lake chubs and other fishes in a temperate stream

Baited and unbaited minnow traps were set in Catamaran Brook and the Little Southwest Miramichi River, New Brunswick, and checked every 4 h to determine the diel activity pattern of four species of stream-dwelling fish (threespine stickleback (Gasterosteus aculeatus), juvenile white sucker (Catostomus commersoni), blacknose dace (Rhinichthys atratulus), and lake chub (Couesius plumbeus)). Secondary goals were to determine whether the presence of bait inside minnow traps affected the diel patterns of captures and to compare patterns of lake chub captures in minnow traps with movement through a nearby fish-counting fence. All fish except lake chubs were diurnal, although strict diurnality was less obvious when bait was present in the traps. Lake chubs, which are normally diurnal in the laboratory, were captured mostly near dawn or dusk in unbaited traps, throughout the day in baited traps, and mostly at night at the fish-counting fence. We infer that chubs are active mostly at dawn or dusk, except (i) when strong food cues are present, in which case their activity may extend into the day, and (ii) during the spawning migration, when they move mostly at night. Relative inactivity by chubs during the day may be caused by the presence of piscivorous birds such as kingfishers and common mergansers, whose hunting efficiency may be higher under brighter light.