Rodent Control Practices Research Articles

Evaluation of the impact of chemical control on the ecology of Rattus norvegicus of an urban community in Salvador, Brazil.

The presence of synanthropic rodents, such as Rattus norvegicus, in urban environments generates high costs of prophylaxis and control, in large part due to the environmental transmission of the pathogenic spirochete Leptospira interrogans, which causes leptospirosis. In Salvador, Brazil, The Center for Control of Zoonosis (CCZ) is responsible for planning and implementing Rodent Control Programs (RCP) which are based on chemical rodenticide. However, these strategies have not been standardized for use in developing countries. This study aimed to identify the effect of a chemical control campaign on the demographic variables of urban R. norvegicus, analyzing relative abundance, sex structure, body mass, and age of the population, as well as the characterization of spatial distribution among households, rodent capture campaigns and interventions. This study was carried out during 2015 in three valleys of an urban poor community in Salvador. Individuals of R. norvegicus were systematically captured before (Pre-intervention) and three months (1st post-intervention) and six months (2nd post-intervention) after a chemical control intervention conducted by the CCZ in two valleys of the study area while the third valley was not included in the intervention campaign and was used as a non-intervention reference. We used analysis of variance to determine if intervention affected demographic variables and chi-square to compare proportions of infested households (Rodent infestation index-PII). During the chemical intervention, 939 households were visited. In the pre-intervention campaign, an effort of 310 trap nights resulted in 43 rodents captured, and in the 1st and 2nd, post-intervention campaigns resulted in 47 rodents captured over 312 trap nights and 36 rodents captured over 324 traps-nights, respectively. The rodent infestation index (PII) points did not show a reduction between the period before the intervention and the two periods after the chemical intervention (70%, 72%, and 65%, respectively). Regarding relative abundances, there was no difference between valleys and period before and two periods after chemical intervention (trap success valley 1: 0,18; 0,19; 0,18 / Valley 3 0,15; 0,17; 0,13/ P>0,05). Other demographic results showed that there was no difference in demographic characteristics of the rodent population before and after the intervention, as well as there being no influence of the application of rodenticide on the areas of concentration of capture of rodents between the campaigns. Our study indicates that the chemical control was not effective in controlling the population of R. norvegicus and provides evidence of the need for re-evaluation of rodent control practices in urban poor community settings.

Adoption of rodent pest management strategies by farmers of district Ludhiana, Punjab

The present study was conducted to assess adoption of rodent pest management strategies by farmers in District Ludhiana, Punjab during the year 2017-18. Farmers belonging to three villages, namely Barewaal Dogra (maintenance area), Kutbewaal Gujran (neglected area) and Ladiyan Kalan (survey area) having land holding ranging from 2.0-32.0 acres were selected. The pre-dominant rodent pest species in area under study was Bandicota bengalensis followed by Tatera indica, Millardia meltada and Mus boodguga. Education and training was provided to farmers belonging to maintenance and neglected villages whereas free rodenticide baits were distributed among farmers of maintenance village only. In survey village, no such activity was performed and kept as reference area. KAP survey (Knowledge Aptitude and Practice) of farmers before imparting education during paddy crop period revealed similar rodent control practices being used by farmers in all the three selected villages. Subsequent KAP survey during wheat crop period for impact assessment revealed the sustainability of education and training already imparted during paddy crop period. About 41-92% increase in farmers observing recommended rodent control practices during crop production was noticed. So timely education and free rodenticide bait distribution are important factors responsible for adoption and sustainability of rodent control strategies by the farmers. Farmer can save food grains (33.09 kg paddy/acre and 36.39 kg wheat/acre) with an economic benefit (Rs. 500.09-575.66/acre) and cost: benefit ratio of 1: 36 to 1: 39 by using education, training and free rodenticides which will help in food security.

Start-up financing of professional pest control in pig farming in North Rhine-Westphalia in Germany

BackgroundDue to the risk of spreading epizootic diseases through rodents, pest control is mandatory in pig farming in European countries. However, there is limited research focused on rodent control practices, usage of anticoagulant rodenticides, and the acceptance of Pest Control Operators (PCOs) in pig farming in Germany. Therefore, the present study aims to investigate current control practices in pig holdings and to analyze the potential of a financial support on the implementation of professional pest control.ResultsData were collected from monitoring records of PCOs and personal interviews with farmers and PCOs. 33 of 47 farmers, who were offered the possibility to outsource rodent control to PCOs supported by financial contribution of the North Rhine-Westphalian Animal Disease Fund (TSK) for a period of 2 years, joined the project.Despite the widespread opinion that the professional would not be beneficial – the authors figured out that farmers could financially benefit in time saved and by improved rodent control measures from the work of the PCOs. Costs of pest control measures per operation on average did not differ significantly between costs incurred by employment of PCOs (1.310 € per year) and calculated costs that arise by farmers themselves (1.217 € per year).All PCOs used Difenacoum and Brodifacoum against pest infestations. In doing so, the infestation with rodents was reduced and most of the participating farmers assessed the project as successful and employ the PCOs permanently. However, mapping the farm locations to resistance areas of the Rodenticide Resistance Action Committee (RRAC) shows that Brodifacoum was frequently used in areas which are marked as areas that are at low risk or rather have no risk for resistance. The environmental risks, however, are increased in these areas.ConclusionThe instrument of temporal start-up financing professional pest control allows ensuring the continuous engagement of PCOs after the project period. This could possibly lead to long-term effects on the individual farm hygiene and on disease prevention. Nevertheless, important research questions with regard to the application of anticoagulant rodenticides of farmers and PCOs in livestock farming and with regard to risk mitigation measures were generated, meriting further investigation.

Use of anticoagulant rodenticides by pest management professionals in Massachusetts, USA.

Secondary exposure to chemical rodenticides, specifically second-generation anticoagulant rodenticides (SGARs), poses a threat to non-target wildlife including birds of prey. Federal regulations in the United States currently limit homeowner access to SGARs as a way of minimizing this threat. With legal access to SGARs, pest management professionals (PMPs) represent a potential linkage to non-target exposure. There is limited research focused on rodent control practices, chemical rodenticide preferences, level of concern and awareness, or opinions on rodenticide regulations as they relate to PMPs. An online survey was sent to PMP companies across Massachusetts, USA, between October and November 2015. Thirty-five responses were obtained, a 20 % response rate. The preferred rodent control method among responding PMP companies was chemical rodenticides, specifically the SGAR bromadiolone. Respondents varied in their level of concern regarding the impact of chemical rodenticides on non-target species and showed a low level of awareness regarding SGAR potency and half-life. All responding companies reported using integrated pest management (IPM) strategies, with nearly all utilizing chemical rodenticides at some point. Enhanced education focused on SGAR potency, bioaccumulation potential, exposure routes, and negative impacts on non-target wildlife may improve efforts made by PMPs to minimize risk to wildlife and decrease dependence on chemical rodenticide use. Future studies evaluating use of anticoagulant rodenticide (ARs) by PMPs and the association with AR residues found in non-target wildlife is necessary to determine if current EPA regulations need to be modified to effectively reduce the risk of SGARs to non-target wildlife.

Monitoring of Rattus norvegicus based on non-toxic bait containing encapsulated fluorescent dye: Laboratory and semi-field validation study

We tested the applicability of fluorescent non-toxic bait to the wild Norway rat (Rattus norvegicus). We described the temporal dynamics of the production of fluorescent faeces after fluorescent bait consumption in the laboratory and, subsequently, tested the applicability of this monitoring method in a wild rat colony in an outdoor enclosure. In the laboratory experiment, no effect of animal sex on total faeces production was found (P > 0.05). The first fluorescent faeces were detected after 6–7 h; production peaked from 9 to 15 h; and the last detectable faeces were observed 26–27 h after bait administration. The proportion of highly fluorescent faeces to total produced faeces increased to over 80% during the peak period. In the semi-field experiment, 40% of collected faeces in the enclosure were fluorescent and 78.6% of the fluorescent faeces were deposited on the surface on the floor, i.e., only small proportion of fluorescent faeces were found hidden in the shelters, thereby no for monitoring purposes. Both laboratory and semi-field studies indicated a good potential (e.g., palatability and high production of fluorescent faeces per 24 h and their dispersion out of the hidden places) of the use of fluorescent bait for monitoring R. norvegicus in rodent control practices.

Evidence that rodent control strategies ought to be improved to enhance food security and reduce the risk of rodent-borne illnesses within subsistence farming villages in the plague-endemic West Nile region, Uganda

Rodents pose serious threats to human health and economics, particularly in developing countries where the animals play a dual role as pests: they are reservoirs of human pathogens, and they inflict damage levels to stored products sufficient to cause food shortages. To assess the magnitude of the damage caused by rodents to crops, their level of contact with humans, and to better understand current food storage and rodent control practices, we conducted a survey of 37 households from 17 subsistence farming villages within the West Nile region of Uganda. Our survey revealed that rodents cause both pre- and post-harvest damage to crops. Evidence of rodent access to stored foods was reported in conjunction with each of the reported storage practices. Approximately half of the respondents reported that at least one family member had been bitten by a rat within the previous three months. Approximately two-thirds of respondents practiced some form of rodent control in their homes. The abundance of rodents was similar within homes that practiced or did not practice rodent control. Together, our results show that current efforts are inadequate for effectively reducing rodent abundance in homes.

Using long‐term monitoring of red fox populations to assess changes in rodent control practices

Summary Pest control is a global issue for agriculture, health, biodiversity conservation and economy. Anticoagulant rodenticides are used over large areas to control rodent pests and can cause widespread poisoning of nontarget wildlife. In France, bromadiolone is the only pesticide authorized to control the water vole Arvicola terrestris Scherman, in grasslands. Since 2001, legislation has been in place to replace curative treatments by preventive ones and limit the quantity of rodenticide used. As the legislation took effect over time, the impact on red fox Vulpes vulpes populations was monitored. Fox populations and bromadiolone treatments were monitored in the Doubs Department (5000 km² area), France. Fox counts were carried out during spring, and vole control was primarily conducted in autumn. Relative fox densities (Kilometric Abundance Index: KAI) obtained per commune for year n (2004–2009) were related to treatments achieved during year n−1 (2003–2008). Treatments from year n−2 were used to investigate possible delayed responses in fox populations. Kilometric Abundance Index of foxes was significantly related to treatment intensities in years n−1 and n−2. The impact was greatest in a large area (>1000 km²), where intensive treatments were achieved in 2003. Fox KAI generally remained dramatically low in this area until 2005, after which a partial recovery was observed. The same area was treated again from 2006 to 2008 but with only half the amount of bait per hectare that was used in 2003. These treatments were followed by a moderate decrease in fox populations. Synthesis and applications: We have established, for the first time on a regional scale, the negative impact of a rodenticide on fox populations. We have shown that a shift to preventive treatments with reduced anticoagulant rodenticide use is less harmful to fox populations. However, to approach a zero impact, treatments should be reduced further by limitation of bait quantities authorized per hectare and per commune and using alternative methods to chemical control. Long‐term monitoring of wildlife populations using index methods can provide valuable information about the adverse effects of pesticides; therefore, we recommend their inclusion in the assessment of pest management practices.

Use of computer simulation models to encourage farmers to adopt best rodent management practices in lowland irrigated rice systems in An Giang Province, the Mekong Delta, Vietnam

Rice field rats are an important pre-harvest pest of lowland irrigated rice farming systems in Vietnam. Farmers often apply traditional control measures too late for economic benefits to be achieved, due to the progressive inability of rice plants to compensate for damage. The use of computer simulation modelling was examined as a potential alternative approach to the management of rodents in lowland rice crop ecosystems. It was projected that 16 farmers who are involved in action learning cycles using crop simulation models to look at the relationship between timing and effectiveness of different control methods, would change their behaviour about rodent management, so that management is preventative rather than reactionary to pest damage. The study was conducted in three villages (2 treatment villages and 1 reference village) during the autumn-winter cropping season (July-November) in 2009, in An Giang Province in the Mekong Delta of Vietnam. Effects of alternative rodent management practices were explored using APSIM modelling in a farmer participatory approach. The changes in rodent control practices of farmers before and after the involvement in the APSIM modelling approach are also discussed. The study showed that APSIM modelling adequately simulated actual yields at different rodent damage intensities, for the different growth stages of the rice crop. Pre-season yield predictions in response to rat management were the same for farmers' actual rice yields at the treatment and reference sites. The use of the modelling was an integral component of the learning cycle for farmers and extension workers in achieving a clear understanding of the rationale for changing their traditional rodent control strategies. Farmers subsequently changed the timing of rodent management to the tillering stage of crop development instead of later in crop growth after most damage has been done. It is believed that the model has the potential for application in other provinces of Vietnam with similar rice farming systems to those in the Mekong Delta.

Farmers’ participatory research on rodent control in Punjab state: Survey, education, impact assessment and sustainability

Survey of farmers from ten villages of districts Ludhiana, Jalandhar and Sangrur in Punjab (India) from 2000–01 to 2008–09 revealed that farmers’ knowledge, general attitude and rodent control practices were similar across villages. Overall, 60.0–100.0% farmers were found conducting rodent control operations mostly using zinc phosphide without pre-baiting. Farmers (60.0–80.0%) used to conduct rodent control only at maturity stages of crops when rodents exhibit frequent visible movement and inflict extensive damage. After survey, farmers were educated and motivated to conduct rodent control operations as per recommendations. Post-implementation survey of farmers revealed varied level of adoption for different control practices in different villages. Farmers started conducting rodent control operations in an integrated way and used both zinc phosphide and bromadiolone baits (82.0–100.0%). Damage census revealed comparatively less damage to wheat (Triticum aestivun L.) and rice (Oryza sativa L.) crops in villages where education along with free rodenticide baits were provided to the farmers compared to the areas where neither rodenticide baits nor education was imparted. Survey of 20–30 farmers of two villages where training had been previously conducted revealed that the impact remains only while farmers are given free rodenticide baits along with education and field demonstrations. Once this practice is stopped, the use of integrated practices decreased. From the present investigation, it is concluded that a thorough education of the farmers along with the distribution of rodenticide baits at regular intervals is a pre-requisite for successful planning of the community programme in rodent control.

Food Safety and Rodent Control in Leafy Green Crops

Author(s): Newman, Peter; Salmon, Terrell P.; Gorenzel, W. Paul | Abstract: In 2006, spinach contaminated with Escherichia coli resulted in the death of 3 people and over 200 illnesses. The contaminated spinach was traced to a field in central California. In 2007, produce industry representatives developed safety guidelines (known as the Metrics) for lettuce and other leafy green crops. The Metrics addressed encroachment and crop contamination by wildlife and livestock. Rodents are treated by growers and buyers as suspects in the food-borne illness matrix. This has resulted in many unnecessary, ineffective, and expensive rodent control practices in leafy green crops. The Metrics require periodic monitoring of animal activity in and around the crop fields, but there are no specific guidelines on how to monitor for rodents. In 2009/2010, we conducted field work in the Salinas Valley region of Monterey County. This included surveying iceberg lettuce and spinach fields to identify the rodents present and test rodent monitoring techniques. As a result of this fieldwork, a specific index of abundance calculation was developed to enable growers to accurately assess the rodent population in their fields. We reviewed the Metrics and identified all portions related to rodents and rodent control. Monitoring techniques were evaluated for their practicality and ability to detect rodents. Control strategies from the California Vertebrate Pest Control Handbook (CDFA 2008) were combined with the results of the monitoring program to create a pocket-sized field guide containing relevant monitoring and control information regarding rodents and leafy green production.

Urban resident attitudes toward rodents, rodent control products, and environmental effects

Rodent control in urban areas can result in the inadvertent mortality of non-target species (e.g., bobcats). However, there is little detailed information from urban residents about rodent control practices. We evaluated urban rodent control behaviors in two areas of California (southwestern Bakersfield and in proximity to Santa Monica Mountains National Recreation Area (SAMO)) where biologists have observed non-target mortality among carnivores resulting from exposure to anticoagulant rodenticides. Using a mail survey instrument, we asked residents about rodent control practices including products used and application, attitudes toward rodents, and concern about non-target mortality. Forty-one percent of Bakersfield (response rate = 20%) and 59% of SAMO (response rate = 31%) respondents reported rodent or other animal control on their property. Snap traps and anticoagulants were the most commonly used physical and chemical control products, respectively. Many respondents were unsure whether (12% Bakersfield; 17% SAMO) or which (39% Bakersfield; 46% SAMO) chemical products were used on their property. When told of possible non-target effects, a majority of respondents were either very or somewhat concerned. Attitudes toward rodents were relatively negative across all respondents. Respondents who applied control products themselves (as opposed to a third party) were most supportive of ensuring availability of rodent control products. Our results suggest that residents do not readily connect their personal or household activities with larger environmental effects, and highlight potential focal areas for policy evaluation related to wildlife management, such as providing explicit information about potential environmental effects of rodent control products.

Social and cultural dimensions of rodent pest management

Rice production in Vietnam is threatened by rodent pests, with a significant increase in impact reported from 1990 through to the early 21st century. Pre-harvest rice losses are typically 5-10%, with losses of >20% occurring in some years in some regions. Farmers' rodent control practices are generally reactive and rely essentially on chemical and physical methods. Ecologically-based rodent pest management (EBRM) was developed in the late 1990s to manage rodents in rice-based farming systems in Vietnam and other parts of South-East Asia. EBRM combines both cultural and physical rodent management practices such as synchrony of cropping, short 2-week rat campaigns at key periods in key habitats, increasing general hygiene around villages, and use of a community trap-barrier system. Although EBRM has been reported to be economically profitable, the successful adoption of this set of technologies requires community participation. In this paper we address issues relating to the adoption and sustainability of EBRM in lowland irrigated rice fields in the Mekong Delta in Vietnam. We particularly explore the social and cultural mechanisms involved in maintaining community participation to further understand the conditions under which EBRM works and does not work. Positive indications of sustained use of community-based EBRM include: a policy pronouncement from the prime minister directing the use of integrated rodent management; the use of existing cooperatives for developing community actions; budgetary allocation from provincial and local governments; diffusion of EBRM to provinces in the south and north that are not involved in farmer participatory field trials; and the adoption of EBRM by a non-governmental organization, World Vision Vietnam, in their area-development programs.

ECOLOGICALLY BASED MANAGEMENT OF RODENTS IN THE REAL WORLD: APPLIED TO A MIXED AGROECOSYSTEM IN VIETNAM

Rodents cause significant damage to lowland irrigated rice crops in the Red River Delta of Vietnam. A four-year study was conducted in 1999-2002 to examine the effectiveness of applying rodent control practices using the principles of ecologically based pest management. Four 100-150 ha study sites adjacent to villages were selected and farmers on two treated sites were asked to follow a set of rodent management practices, while farmers on the untreated sites were asked not to change their typical practices. Farmers on the treated sites were encouraged to use trap-barrier systems (TBS's; 0.065-ha early planted crop surrounded by a plastic fence with multiple capture traps; one TBS for every 10-15 ha), to work together over large areas by destroying burrows in refuge habitats soon after planting (before the rats reestablish in the fields and before the onset of breeding), synchronizing planting and harvesting of the their rice crops, cleaning up weeds and piles of straw, and keeping bund (embankment) size small (<30 cm) to prevent burrowing. A 75% reduction in the use of rodenticides and plastic barrier fences (without traps or an early crop) was achieved on treated sites. The abundance of rodents was low after implementation of the management practices across all sites. There was no evidence for an effect of treatment on the abundance of rodents captured each month using live-capture traps, and no difference in damage between treatments or in yields obtained from the rice crops. Therefore, ecologically based rodent management was equally effective as typical practices for rodent management. Farmers on the treated sites spent considerably less money applying rodent control practices, which was reflected in the comparative increase in the partial benefit:cost of applying ecologically based rodent management from 3:1 on treated sites and untreated sites prior to the implementation of treatments to 17:1 on treated sites in the final year of the project.

THE ROLE OF RODENTS IN SILVO-PASTORAL SYSTEMS IN RAJASTHAN

SUMMARY Thirteen species of rodents are identified as causing severe damage to silvo-pastoral systems in Rajasthan: Funambulus pennanti, Gerbillus gleadowi, G. nanus, Golunda ellioti, Hytrix indica, Meriones hurrianae, Mus platythrix, M. cervicolor, Rattus cutchicus, R. gleadowi, R. meltada, R. rattus, and Tatera indica. The extent of damage by these rodents at different stages of the growth of tree plantations and fodder grasses is discussed. Appropriate rodent control practices are described.