Bait Preferences Research Articles

Evaluation of Bait Acceptance and Immune Response in Local Dogs during an Oral Rabies Vaccination Field Study in Morocco.

The objective of this study was to evaluate the bait preference of three selected bait types by local dogs and the induced immunogenicity of the oral rabies vaccine strain SPBN GASGAS in Morocco. The vaccine strain, combined with different bait types, has been tested in many different settings, but not yet in northern Africa. Overall, bait consumption and preference were similar in other studies using the same materials (bait type and sachet). The intestine bait had the highest acceptance rate (97.6%, 95%CI: 87.4-99.9), followed by the egg bait (83.0%, 95%CI: 69.2-92.4). Only 52% (95%CI: 37.4-66.3) of the dogs showed an interest in the fish meal bait. However, considering the successful release of the contents of the sachet (blue-dyed water) into the oral cavity, the egg bait (65.7%, 95%CI: 47.8-80.9) scored better than the intestine bait (51.7%, 95%CI: 32.5-70.6). The dogs selected for the immunogenicity study were offered the egg bait containing a sachet filled with SPBN GASGAS (3.0 mL, 107.5 FFU/mL) or were given the same dose by direct oral administration (d.o.a.). In addition, several dogs were vaccinated by the parenteral route (s.c.) using a commercially available inactivated rabies vaccine. Unfortunately, due to the COVID-19 pandemic and subsequent travel restrictions, it was not possible to collect blood samples directly after vaccination. The blood samples were collected pre-vaccination and on five occasions between 450 and 1088 days post vaccination. The seroconversion rate, as determined for rabies-virus-neutralizing antibodies by the FAVN test, was significantly lower than that found for binding antibodies, as determined by ELISA, for all blood samples collected post vaccination. No treatment effect (bait, d.o.a., s.c.) could be seen in the seroconversion rate. At 15 months post vaccination, 84.2% of the dogs offered vaccine bait still tested sero-positive in ELISA. Only after 3 years was a clear drop in the seroconversion rate observed in all three treatment groups. This study confirms the long-term immunogenicity of the oral rabies vaccine SPBN GASGAS in dogs under field conditions.

Olfaction foraging in visually oriented tropical arboreal ants Oecophylla smaragdina: Implications for insect predation studies using artificial sentinel prey

AbstractBecause of the brief and cryptic nature of predatory behavior, sentinel prey has been widely adopted as an indirect way to identify predators and understand trophic interactions. However, sentinel prey presents only static visual cues, potentially biasing toward visually oriented predators while ignoring those that utilize other sensory cues for foraging. Despite this, the effectiveness of sentinel prey has rarely been tested. In this study, we focused on the weaver ant Oecophylla smaragdina Fabricius (Hymenoptera: Formicidae), a keystone predator widespread in the Asian and Australian tropics. As this species has large eyes and is known to visually navigate in its arboreal habitats, we hypothesized that it relies on visual cues to forage and that its predatory behavior will be captured by caterpillar‐shaped sentinel prey. Ants were collected as colonies, and preference trials on baits were conducted using combinations of olfactory and static visual cues, including the caterpillar shape. Surprisingly, O. smaragdina showed little or no preference for baits in the absence of olfactory cues and did not differentiate the shapes of baits regardless of olfactory cues. Our results indicate that O. smaragdina is likely to make predatory decisions based primarily on olfactory cues, whereas visual cues might be used for other behaviors. Furthermore, O. smaragdina is likely to be left out by the predation studies using sentinel prey models, which is particularly alarming considering the dominant role of this species in the trophic interactions of tropical rainforests. Our study demonstrates that morphological characteristics, arboreal habitats, and visually oriented behavior do not necessarily suggest the use of static visual cues for predatory decisions. We suggest that sentinel prey models should not be used alone when the dominant predators are unlikely to use visual cues to make predatory decisions.

Alternatives to corn for baiting wild pigs

AbstractWe examined dietary preferences of wild pigs to discern possible bait alternatives to corn. Captive trials were conducted during spring and fall 2021 in the Wild Pig Research Facility at Kerr Wildlife Management Area, Hunt, Texas, USA. We conducted 2‐choice tests by allowing wild pigs to feed ad libitum on soybeans, split peas, mealworms, and peanuts (spring 2021), and oats, acorns, earthworms, and peanuts (fall 2021), always with corn available as a second choice for reference. In each trial, we used proportion of test bait eaten versus total bait eaten, and relative access to both food sources as indices of bait preference. We found that a higher proportion of corn was consumed than that of any test bait in the spring, but not in the fall. However, we found that earthworms were consumed more than any other test bait in the fall. We also found that corn was accessed more than test baits in the spring, but not more than earthworms or peanuts in the fall. Greater consumption of earthworms relative to other baits, and access rates comparable to corn indicated that earthworms could be an effective alternative bait to corn. Our work suggests that alternative baits may be equally or more effective for attracting wild pigs than corn.

Mechanical and Chemical Management of Wild Boar (Sus scrofa L.) Pests in the Bireuen District of Aceh Province

The agricultural sector, including food crops, plantations, fisheries, livestock, and forestry, plays an essential role in the development of the national economy development. The infestation of pests, diseases, and weeds is one of the constraints to obtaining optimal crop production. One of the major pest, especially on estate crops, is wild boar (Sus scrofa L.). The damage caused to plantation commodities, especially those bordering the forest, is very significant. Therefore, it needs to be controlled. The objectives of this research were to study: Food bait preference, mechanical control using hook bait and snare trap, and chemical control using zinc phosphide as acute poison. This research was designed using block randomized experimental design to treat of baits (banana fruit, jackfruit, and cassava) and treatment villages (Puuek and Jambo Dalam in Peulimbang District; Blang Beururu and Ara Bungong in Peudada District). Data were analyzed using Minitab v. 16 for windows 8, then analyzed using the Tukey test at a level of α=5%. Consumption of wild boar in Blang Beururu Village was the lowest and significantly different from the other three villages. Bait preference trial showed that wild boar consumed more cassava in Peulimbang and more jackfruit in Peudada. Jackfruit, cassava, and banana baits were consumed in the same amount. Therefore, we used cassava for the subsequent trial. Wild boar consumed poison bait and hooked bait in Peudada higher than in Peulimbang. Poison bait, hook bait, and control were consumed simultaneously at the same amount. Wild boar was caught by snare trap more in Peulimbang than in Peudada.

Characterization of bluefish baits (keeled mullet, leaping mullet, and sardine) in regard to biochemical and physical properties: bait preference of bluefish

The fishing industry needs alternative baits that are not based on resources available for human consumption. In order to develop artificial baits, first the preferred baits should be determined, and then their biochemical and physiological composition should be identified. The aim of this study was to determine bluefish bait preferences and reveal the biochemical composition and physical characteristics of the preferred baits. In this study, keeled mullet, leaping mullet, and sardine species were found to have the highest catch, respectively. The highest texture hardness and whiteness colour values were found in keeled mullet, which had the highest catch efficiency for bluefish fishing. The highest palmitoleic acid content was found in keeled mullet at 25.86% (16.93% in leaping mullet and 17.05% in sardine). However, the highest PUFA content was found in sardine (15.56%), followed by leaping mullet (13.97%), and then keeled mullet (11.32%). As for the amino acid compositions, it was determined that glutamic acid and serine content, which are known to have positive effects on feed intake, were higher in keeled mullet. In regard to volatile components, mullet species were especially rich in total alcohol, aldehyde, ketone, and amines, while sardines were rich in hydrocarbons and furans. Hexanal and heptanal compounds, known as fish aroma, were determined at high rates in keeled mullet. It can be concluded that these components may be attractive to bluefish. The data presented in this study may be useful for the production of artificial bait.

BAIT PREFERENCES BY DIFFERENT SMALL MAMMAL ASSEMBLAGES FOR EFFECTIVE CAGE-TRAPPING

The ecological study of small mammals often uses the cage-trapping method, installed with baits. Capture rates vary according to different baits used. We want to determine the bait preferences by different small mammal groups. The cage-trapping approach used common domestic bait types available, namely, aromatic banana, sweet potato with peanut butter, oil palm fruit, dried salted fish, jackfruit, and roasted coconut flesh. Sampling was conducted in three different habitat categories, namely urban, semi-urban, and recreational forests, located in Selangor, Malaysia, for one year. A total of 537 small mammals from 15 species were sampled, which was then grouped into seven groups (i.e., Rattus sp., Maxomys sp., Sundamys sp., Leopaldamys sabanus, Suncus murinus, squirrels, and Tupaia glis). Bait preferences were significantly different among the different small mammal groups, i.e., F (6,35) = 5.621, p = 0.000, with bananas shown to be most preferred bait, followed by oil palm fruits and sweet potatoes. Non-metric multidimensional scaling (nMDS) analysis revealed that the Rattus species encompassed the most diverse bait preference, while S. murinus and L. sabanus were the most selective. Muridae preferred sweet potatoes with peanut butter over bananas, while Sciuridae and Tupaiidae preferred bananas, and Soricidae preferred dried salted fish. This study elucidates the most effective bait selection for different small mammal assemblages, serving as a guide to increase capture rates when sampling targeted population of small mammals. Apart from that, it is helpful for effective rodent pest control.

Factors Influencing the Efficiency and Attractiveness of Land Snails to Different Baits under Laboratory and Field Conditions, at Sharkia Governorate

The attractiveness of poison and non-poison baits to land snail,Monacha cartusiana were tested under laboratory and field conditions. Results in laboratory revealed that the highest attractive rate was recorded for non-poison baits the type sugarcane syrup (32.5% in 25.37 min.) followed by vanilla (28 % in 6.82 min.), while yeast showed the lowest one (3% in 1.0 min.) at 5 cm distance. Concerning weight of bait preference, 2 g proved superior to other tested weights in attractive snail numbers for all baits except sugarcane syrup with 8 gm. Regarding metaldehyde compounds poison baits, the highest mortality percentages were (93.33 %) for Gastrotex treated with 75% soil moisture 14 days post treatment and for Molotov (73.33 %) at 100% soil moisture 21 days post treatment. In the field studies, both of light blue Metarol (40 pellets/m2) and orange Molotov (54pellets/m2) proved to be more effective in reducing snails numbers than green Gastrotex (26 pellets/m2), while blue Gentrazol (102 pellets/m2) was found to be the lowest toxic one, by the end of the experiment (7days). Regarding direction effects revealed that North and East for Mesurol and Western-North and Eastern-North direction for Gastrotex, recorded the greater number of attractivity in the first day than the second and third days. The general mean of Mesurol exhibited slightly increase than metaldehyde in snail attractively. Our results highlight some factors to improve molluscicide baits performance which enhance attractiveness rate, helping in formulating new policies for better management of M. cartusiana snail.

Oral bait preferences and feasibility of oral rabies vaccination in Bangladeshi dogs

Oral rabies vaccination (ORV) can increase rabies vaccination coverage among dogs that are inaccessible to parenteral vaccination (i.e., inaccessible dogs). Because bait uptake can differ according to the bait attractant used and dog characteristics, we evaluated proportion of bait uptake and time to bait uptake using three bait formulations. We looked for associations between bait uptake and dog characteristics (temperament, age, and body condition) and assessed the efficiency of using these bait formulations, as measured by number of dogs vaccinated per hour.A total of 356 baits were offered to free roaming dogs in urban and peri-urban districts of Bangladesh. Fish baits were ignored by 86% (n = 122; 95% CI: 79–91%) of dogs, whereas 60% (n = 45; 95% CI: 49–70%) consumed egg baits and 89% (n = 124; 95% CI: 83–93%) consumed intestine baits. Among the consumed baits, dogs fully consumed 56% (n = 10; 95% CI: 34–75%) of fish baits, 84% (n = 38; 95% CI: 71–92%) of egg baits, and 98% (n = 122; 95% CI: 94–100%) of intestine baits. Among inaccessible dogs, no associations were found between bait uptake and dog characteristics in either bivariate or multivariate analyses. Bait consumption averaged 2 dogs per hour for fish baits, 10 dogs per hour for egg baits, and 18 dogs per hour for intestine baits.The absence of association between bait type preference and individual dog characteristics simplifies the process of choosing attractants for oral rabies vaccines. While intestine attractants achieved highest uptake, egg baits may prove a suitable compromise when considering biological and operational constraints. The efficiency of ORV was demonstrated when compared to parenteral vaccination of free-roaming dogs previously described.

The Effects of Laboratory Rearing Diet on Recruitment Behavior of Wasmannia Auropunctata (Hymenoptera: Formicidaea)

Wasmannia auropunctata (Roger) (Hymenoptera: Formicidae) is among the world's worst invasive species, and there is an increasing need for effective control methods for this species. Existing chemical treatments and baits used in managing other invasive ant species may not be as effective for managing W. auropunctata. Development of effective ant control treatments and baits depends on laboratory experiments to test the potential efficacy of a large number of products and control methods prior to implementation of large-scale field studies. However, anecdotal evidence suggests that laboratory-raised W. auropunctata may respond differently than their wild counterparts to bait types, and if this is the case, laboratory trials may not accurately predict results under field conditions. Here we report on experimental research investigating whether ant colonies raised in laboratories, and those in the field, show different patterns of recruitment to non-toxic baits. Laboratory and wild colony recruitment to non-toxic Hawaii Ant Lab gel bait, pureed tuna, and 50% gelled sucrose solution was measured via multi-choice and no-choice field recruitment studies. Secondly, we discuss experiments testing whether the bait preference of laboratory-raised W. auropuncata varies with their base diet. We tested 4 base diets: (1) lipid rich, (2) protein rich, (3) carbohydrate rich, and (4) a “complete” diet with lipid, protein, and carbohydrates offered as a buffet. Overall, we found that laboratory colonies differed from wild W. auropunctata in their foraging behaviors in no-choice and multi choice experiments, particularly in their levels of recruitment to the Hawaii Ant Lab gel bait. This contrast indicates that experimental trials may give misleading indications of potential outcomes of field trials. Further research is needed on optimal laboratory diets for laboratory-reared ant colonies. However, our results suggest that behavioral differences may be mitigated if colonies are maintained on a nutritionally limited diet while conducting laboratory experiments.

Please come again: attractive bait augments recapture rates of capture-naïve snowshoe hares

Abstract ContextCapture–recapture sampling is one of the most commonly used methods for monitoring population demographics and is needed in a wide variety of studies where repeat sampling of individuals is desired. Although studies employing capture–recapture methods often assume unbiased sampling, it is well established that inherent capture biases can occur with these methods, including those related to baits. Reducing sources of sampling bias and augmenting recapture reliability is necessary for capture-dependent studies. However, few studies have examined the efficacy of baits on individuals with variable capture experience. AimsTo investigate the use of an attractant-augmented bait in enhancing capture–recapture probabilities for snowshoe hares (Lepus americanus). MethodsTo examine the efficacy of different attractant-augmented bait types, a variety of baits were created, with bait preference tested on a captive hare. Because a strawberry jam-based bait was preferentially consumed (in comparison with other tested baits), the effectiveness of this attractant in enhancing capture–recapture rates was subsequently examined in wild hares, using paired live-trapping field trials (n=6 trials). ResultsLive-trapping trials showed that although overall hare capture rates were not affected by the use of a jam-based bait, recaptures were 33.1% higher in capture-naïve individuals exposed to our attractant. This was not the case for hares with prior capture experience; such hares had an equal likelihood of being recaptured regardless of the bait type used. ConclusionsThe tested attractant improved recapture rates of capture-naïve hares. ImplicationsStudies relying on high recapture rates should use methods that maximise recapture rates wherever possible, including the use of baits that may augment recaptures in capture-naïve animals.

The feeding preference of sunda scops-owl (Otus lempiji horsfield) to bait

Oil palm is the most important plantation commodities in Indonesia due to planting area and productivity. There are some constrains faced by oil palm management, one of them is plant pest including insects and rats. Insects and rats have a high reproduction capability and severely damage to oil palm plantation. An effective and environmentally control of these pests using natural enemies, one of them owl. The sunda scops-owl (Otus lempiji Horsfield) was tested in the Laboratory of Vertebrate Pest, IPB University using different types of feed, to calculate the level of bait preference. Method used was bi-choice test, comparing the feeding of preference bait between: (a) rat and larvae of beetle, (b) rat and lizard, (c) rat and fish, (d) rat and cricket. Before and after treatment, all baits were weighed to determine the amount consumption and preference to feed. The data showed that the sunda scops-owl consumed rat higher than larvae of beetle, lizard, fish, and cricket, and significantly different.

Oral bait preferences for rabies vaccination in free-ranging black-backed jackal (Canis mesomelas) and non-target species in a multi-site field study in a peri-urban protected area in South Africa

Black-backed jackals (Canis mesomelas) are small meso-predators that occur in the wild and around cities and towns in southern Africa and have been associated with the spread of rabies in South Africa. Oral bait rabies vaccine has been used in Europe and the USA for the control of rabies in reservoir species. The effectiveness of an oral vaccination strategy depends not only on the efficacy of the vaccine but on the uptake of the bait in the target species. This study evaluated factors associated with the uptake of oral bait by free ranging jackal and other wildlife species in a multi-site field study in Gauteng Province, South Africa. Three different baits were offered: commercial fishmeal polymer, pieces of red meat and chicken heads. Bait uptake was observed using camera traps and patterns of uptake assessed by multiple correspondence analysis and Cox proportional hazards models. In general, all the baits were well accepted with an uptake of 91%. Median consumption time of bait for jackal was 18 h (IQR: 8−21 hours; range 7−66 hours) and for all other species it was 21 h (IQR: 4–44, range 1–283). In species other than jackals there was a faster uptake in the winter months when less food was available, and the vegetation was sparse, whereas jackal showed no seasonal preference. Jackal consumed 20% of baits placed and took all three bait types but showed a clear preference for chicken heads if available (Hazard ratio (HR) = 3.41; 95%CI: 1.16–9.99; p = 0.025). Species other than carnivores preferred fishmeal polymer or red meat. Jackals showed no preference for time of day whereas herbivores and other species clearly preferred day; other carnivores preferred either day or night but not both, depending upon species. This study showed that chicken heads may be the preferred bait type for oral vaccination of black-backed jackal in this area, and that consideration should be given to placing bait during summer and at dusk, in order to minimize uptake by non-target species.

Winter Activity of Ants in an Urban Area of Western Japan

During winter, foraging activity of ants is considered low in temperate regions. Winter activity of ground-dwelling ants was investigated using bait traps and quadrat sampling in an urban area of Fukuoka City, western Japan. Six study sites were grouped into two categories: 4 open land types and 2 forest types. A total of 18 ant species were recorded between the end of January and beginning of March. The foraging activity of ants was generally low, except during relatively warm periods when the surface ground temperature was above 6℃–7℃ or soil temperature was above 4℃–5℃. Tetramorium tsushimae, Messor aciculatus, and Pheidole noda were the most abundant in the open land type, whereas Nylanderia flavipes, P. noda, and Crematogaster osakensis were the most abundant in the forest type. Bait preference varied among the different species, e.g., P. noda preferred tuna over honey, whereas N. flavipes similarly responded to tuna and honey. This is the first detailed study on the relationship between temperature and ant activity in Japanese mainland fauna.

COMMENSAL SMALL MAMMAL SPECIES AND BAIT PREFERENCES IN URBAN AREAS OF PENANG ISLAND

Physical trapping is an important first step in controlling pest populations and species identification; and bait preferences are crucial information for effective management. This study was conducted to explore species diversity and bait preferences of commensal species in urban areas on Penang Island. Live trapping was carried out in eight sampling sites on Penang Island in commercial and residential areas. Eight different type of baits were used; apple and peanut butter (APB), white bread and peanut butter (BPB), salted fish (SF), salted fish and peanut butter (SFPB), white bread and fish extract (BFE), fried chicken leftover (FCL), vegetables and peanut butter (VPB) and sausages (S). The most successful bait was the high protein bait, fried chicken leftover (FCL), with a capture success rate of 35.56%. We also analysed the bait preferences for the different species of small mammals captured in our study. Five species of small mammals were captured in our study sites: Rattus norvegicus, Rattus rattus, Mus musculus, Bandicota bengalensis and Suncus murinus. Norway rats, R. norvegicus was the most trapped species in commercial areas whereas lesser bandicoot rats, B. bengalensis was the most captured species in residential areas.

Bait preferences of Australian dung beetles (Coleoptera: Scarabaeidae) in tropical and subtropical Queensland forests

AbstractDung beetles (Scarabaeinae) are mainly coprophagous. Globally, many species co‐exist with large mammalian fauna in grasslands and savannahs. However, tropical and subtropical rainforests, where large herbivorous mammals are scarce, support numerous dung beetle species. Many rainforest dung beetles have been shown to be generalist saprophages or specialists on non‐dung food resources. In Australian rainforests, observations of native dung beetles have indicated that some species are attracted to other resources such as fruit or fungi, although the extent to which this occurs is not known. To learn more about the diet breadth of Australian native rainforest dung beetles, we assessed their attraction to a range of baits, including two types of dung, four types of carrion from both vertebrates and invertebrates, three types of rotting fruit and rotting mushrooms. We primarily surveyed rainforest sites but included two dry open‐forest sites for comparisons. Of the two groups of Australian native dung beetles (Onthophagini and Australian endemic genera), the latter dominated the rainforest dung beetle fauna and were attracted to a greater variety of baits compared with Onthophagini. The Onthophagini were dominant in open forest and were more likely to be attracted to a particular bait type, primarily dung. Our findings suggest that many of the species belonging to the ‘Australian endemic genera' are generalist feeders and their ability to utilise a range of food resources contributes to their abundance and diversity in Australian rainforests.

Fresh meat baits are currently the only available effective option to detect low‐density Vespula germanica (Hymenoptera: Vespidae) populations in South Africa

AbstractThe eusocial wasp Vespula germanica is a problematic invasive species in the Southern Hemisphere regions. Especially in New Zealand, Tasmania and Argentina, population densities can be very high and result in large negative impacts. In these regions, the development of baits is used not only to monitor population sizes but also to poison wasps when they return with treated baits to their nests. In contrast, this wasp has been present in South Africa since 1974 but is still confined to a small geographical area. Therefore, detection of the presence of V. germanica with a low level of false negatives is important. The foundation of such a monitoring strategy is a reliable bait or lure that can be placed, in a standard way, in different environments to detect wasp presence. In this study, we tested two baits and two lures at eight localities in 2013 and two baits and four lures at nine localities in 2014. Trap catches confirm low population densities of the target species even in the core of its distribution in South Africa with on average between 3 and 11 wasps (median of 0) caught per trap. Confirming classical bait preference studies, meat baits, specifically lean smoked ham and lean beef mince, trapped significantly more foragers in both sampling years than the unbaited control treatments. However, all catches using synthetic lures with various compounds known to be attractive to Vespula species were almost always indistinguishable from control treatments. Consequently, more research is required in optimising baiting of V. germanica in South Africa, where it occurs at relatively low densities and worker activity peaks when seasonal conditions are unfavourable (hot and dry). Low population densities could explain why synthetic lures that are effective in other invaded continents were not effective in South Africa.

Morphology and Bait Preference of Black Rat (Rattus rattus) in the University Community in Nigeria: Obafemi Awolowo University as a Case Study

Aims: This study assessed the morphology and the bait preference of black rat (Rattus rattus) in Obafemi Awolowo University student hostel with the aim of controlling the population of black rat in the students’ hostels.
 Place and Duration of the Study: The study was carried out at Obafemi Awolowo University which is situated in Ile-Ife, an ancient city in the Southwestern Nigeria and lies between latitudes 7°28′N and 7.467°N and longitudes 4°34′E and 4.567°Ewith a landmass of 5,506 hectares between December 2017 and February 2018
 Methodology: Locally made metal traps (cage traps) (Plate 1) contains baits were placed fortnightly in various sampling locations (Awolowo, Fajuyi, Angola, Akintola, Mozambique and Moremi halls of residence) for a period of 3 months between the months of December 2017 to February 2018. The traps were set around the dark corners of the sites in the evening and collected the following morning (6.00am).
 Results: A total of 236 black rats (Rattus rattus) were caught (81 male & 155 female), with the female having the highest weight (238.30 g). Among the baits used, fried fish caught the highest number of the black rat (58%) followed by beans cake (akara) (28%) and the locust bean (14%). There was a positive correlation in the morphology of the black rat caught in all the hostels.
 Conclusion: The black rats in the University student hall of residence were of the same family and genus, and fried fish is the best-preferred bait.

Previous diet affects the amount but not the type of bait consumed by an invasive ant.

Recent research on multiple invasive ant species has revealed the importance of carbohydrates for achieving high activity levels and outcompeting native ants. However, comparatively little is known about the role of diet and macronutrient preferences for uptake of insecticidal baits used to control invasive ants. We tested whether diet affected yellow crazy ant (Anoplolepis gracilipes Fr Smith) survival and behavior, and whether bait preference would be complementary to past diet. We found that colonies fed only crickets for 28 days had fewer live workers and queens, and less brood per live queen than colonies fed crickets + honeydew but did not differ significantly from colonies fed only honeydew. Colonies that had been fed only crickets were more active (as assessed by interaction with a novel object), retrieved 16-17 times more bait per worker overall, and consumed more of the six bait types than cricket + honeydew and honeydew-only fed colonies. However, prior diet did not affect bait choice. The two highest sugar bait formulations combined accounted for most of the bait consumed across all treatments (cricket-only 74.8% ± 28.1; cricket + honeydew 69.2% ± 12.4; honeydew-only 62.5% ± 30.4). Yellow crazy ant colonies fare better without protein than without carbohydrates. Yellow crazy ants ate the most bait when fed only crickets but did not choose baits complementary to their previous diet. Baits in a sugar-rich carrier may be most effective for the control of yellow crazy ants, regardless of the relative availability of macronutrients. © 2019 Society of Chemical Industry.

Evaluation of food baits to capture Drosophila suzukii in the southern of Brazil.

Drosophila suzukii is one of the main pests of small fruits in the world. An effective monitoring is fundamental to detect the presence of the fly and to predict the infestation of fruits in new areas. We evaluated the food baits Ceratrap®, Torula®, Biofruit®, Suzukii Trap®, apple cider vinegar, and a homemade mixture comprising wine, vinegar and molasses (WVM) for D. suzukii attractiveness, and if reproductive stage affects females attraction and capture in the different baits. Bait selectivity of non-target insects was assessed. The preference of adults between ripe blackberry fruit and the food baits was also evaluated. Adults showed a higher attraction (61.97% of the captured insects) to the WVM mixture than to Ceratrap® (1.32%), Torula® (0.52%), Biofruit® (13.15%), Suzukii Trap® (17.6%), and apple vinegar (5.4%). Considering the attractiveness to D. suzukii, Suzukii Trap® and apple vinegar were the most selective to non-target insects. In general, reproductively immature females showed a preference for Biofruit®, apple vinegar, and WVM, whereas mature females did not show bait preferences. Adults preferred ripe blackberry fruit over the WVM mixture. Understanding the field behavior of D. suzukii is of foremost importance to estimate insect population density and outline pest management strategies.

Laboratory methods of estimation of biological efficiency of plant protection rodenticides from voles of genus Microtus

Long-term laboratory studies resulted in the improvement of the regime of keeping and testing of voles: Microtus arvalis Pall., M. rossiaemeridionalis Ognev and M. socialis Pall.. Methods of primary testing of new rodenticides and bait products, determination of LD50 and estimation of resistance to anticoagulant rodenticides were adapted for gray voles of the genus Microtus. Rodenticides testing on laboratory bred individuals in group testing scheme included experimental reconstruction of field treatments conditions, such as cool temperature regime and alternative juicy feed. The test methods with temporally kept wild-caught Microtus voles were used in the study of level of resistance and bait preference in certain habitats, and also as an additional method for testing the water vole Arvicola terrestris L., for which the method of maintenance of laboratory colonies, evaluated for Microtus voles, were not applicable. New scheme of estimation of resistance level in lab conditions is based on discrimination doses, given to experimental samples of voles, i.e. 30 mg/kg of Etilfenacin in 3 days for anticoagulants of first generation, or single dose 1 mg/kg of Brodifacoum for second generation.