Vertebrate Pest Research Articles

Molecular Identification and Genetic Variation of Rattus Species From Oil Palm Plantations of Malaysia Based on Mitochondrial Cytochrome Oxidase Subunit I (COI) Gene Sequences.

Rats (Rattus species) are the most notorious vertebrate pests in Malaysian oil palm plantations. Although many studies have been conducted on Asian rats, little attention has been paid to their species composition and phylogenetic relationships in oil palm plantations in Peninsular Malaysia. We determined the mitochondrial cytochrome oxidase subunit I (COI) gene sequence (708 bp) for 216 individual rats collected from five oil palm plantations in Peninsular Malaysia. Phylogenetic analysis in conjunction with comparison with sequences from the nucleotide sequence database revealed five distinct lineages in the Malaysian oil plantations: Rattus tiomanicus, Rattus argentiventer, Rattus exulans, Rattus tanezumi, and a taxon corresponding to the Malayan house rat, which was most frequently observed (∼50%). The last taxon has traditionally been classified as a synonym of Rattus rattus (Rattus rattus diardii) or Rattus tanezumi, but our phylogenetic analysis placed it as an independent lineage, which is not particularly closely related to R. rattus or R. tanezumi, and which we refer to as Rattus diardii. The construction of the network showed that there is considerable genetic variation within the lineages of R. diardii and R tiomanicus, suggesting that these two species are native to the Malay Peninsula.

State‐wide prioritisation of vertebrate pest animals in Queensland, Australia

Invasive organisms are key drivers of environmental change globally. Both native and non‐native species can become pests that require management or control. Vertebrate pest animals may cause a range of economic, environmental and social impacts for which various plans are developed at a local, state and national scale to aid their management. There are multiple vertebrate pest species in Australia which vary in the type and severity of their negative effects. Prioritisation of these pests and their impacts is critical for management to be cost‐effective. We accessed pest management plans (PMPs) from 66 (of 71) local government areas (LGAs) across the state of Queensland to collate a list of vertebrate pest species present in each LGA. Local government areas were then grouped into easily identifiable regions (Regional Organisation of Councils, ‘ROC’ regions, 10 in all) and vertebrate pest species lists were collated for each region. At regional workshops, each pest species was ranked as no, low, medium or high priority by stakeholders. Rankings were used to develop impact scores resulting in a priority list of vertebrate pest animal species at the state level. Fifty‐three species were identified in individual LGA PMPs of which 25 were considered priorities at the regional level. Most species prioritised at the state level were mammals, with Wild Dogs (including Dingoes; Canis familiaris), Feral Pigs (Sus scrofa) and Feral Cats (Felis catus) being the three highest ranked. Similarities in priority species were evident across ROC regions, however, several regions prioritised pests specific to their location. The data supported a further amalgamation of the 10 ROC regions into five main groups based on the set of vertebrate pest species that were present. Prioritisation lists should be regularly updated as technologies develop, established pest animal impacts change and new species incursions occur.

Managing vertebrate pest Sambar Deer at low abundance in mountains

SummaryInvasive species such as vertebrate herbivores cause threats to native ecosystems through causing changes to vegetation composition and structure, competition, ecosystem engineering, impacts on soil, and through spreading disease. In the mountainous country of Australia, Sambar Deer (Rusa unicolor) are becoming an increasing threat to fragile and endangered ecosystems, which are also facing other significant threats such as climate change. Methods for ameliorating these impacts are currently limited to lethal control programmes through shooting or fencing key areas. Fencing is not a viable option for large areas and can have large logistical costs as well as negative ecological outcomes. This study aimed to compare two shooting methods (ground shooting vs thermally assisted aerial culling with thermal image operator) for controlling sambar at low densities in a mountainous area. This programme was the first to use this specific thermal technique for deer in mountainous country in Australia. We found that thermally assisted aerial culling was more effective for removing Sambar than ground shooting. Thermally assisted aerial culling removed more Sambar in total, shot more animals per hour, covered a larger search area, was cheaper per hectare covered, and had very high “seen”, “targeted”, and “shot” ratios. Ground shooting sessions were lower in cost overall, but the cost per hectare was higher and rate of Sambar shot was lower than that of thermally assisted aerial culling. Ground shooting did remove more Sambar per hectare as ground shooting focuses on a smaller area, but this advantage is outweighed by the fact that thermally assisted shooting also allowed the concurrent removal of Feral Pigs. This work indicates that thermally assisted aerial culling is the preferred method for effective management of Sambar in an alpine environment. Ground shooting may be beneficial when Sambar are concentrated in key areas or to complement initial knock down by thermally assisted aerial culling.

Scalability of genetic biocontrols for eradicating invasive alien mammals

CRISPR-based gene drives offer novel solutions for controlling invasive alien species, which could ultimately extend eradication efforts to continental scales. Gene drives for suppressing invasive alien vertebrates are now under development. Using a landscape-scale individual-based model, we present the first estimates of times to eradication for long-lived alien mammals. We show that demography and life-history traits interact to determine the scalability of gene drives for vertebrate pest eradication. Notably, optimism around eradicating smaller-bodied pests (rodents and rabbits) with gene-drive technologies does not easily translate into eradication of larger-bodied alien species (cats and foxes).

Quantifying the probability of detection of wild ungulates with the Judas technique.

The Judas technique is often used in control or eradication of particular vertebrate pests. The technique exploits the tendency of individuals to form social groups. A radio collar is affixed to an individual and its subsequent monitoring facilitates the detection of other conspecifics. Efficacy of this technique would be improved if managers could estimate the probability that a Judas individual would detect conspecifics. To calculate this probability, we estimated association rates of Judas individuals with other Judas individuals, given the length of time the Judas has been deployed. We developed a simple model of space-use for individual Judas animals and constrained detection probabilities to those specific areas. We then combined estimates for individual Judas animals to infer the probability that a wild individual could be detected in an area of interest via Judas surveillance. We illustrated the method by using data from a feral goat eradication program on Isla Santiago, Galápagos, and a feral pig eradication program on Santa Cruz Island, California. Association probabilities declined as the proximity between individual areas of use of a Judas pair decreased. Unconditional probabilities of detection within individual areas of use averaged 0.09 per month for feral pigs and 0.11 per month for feral goats. Probabilities that eradication had been achieved, given no detections of wild conspecifics, and an uninformative prior probability of eradication were 0.79 (90% CI 0.22-0.99) for feral goats and 0.87 (90% CI 0.44-1.0) for feral pigs. We envisage several additions to the analyses used that could improve estimates of Judas detection probability. Analyses such as these can help managers increase the efficacy of eradication efforts, leading to more effective effects to restore native biodiversity.

An assessment of animal welfare impacts in wild Norway rat (Rattus norvegicus) management

AbstractNorway rats (Rattus norvegicus) are considered one of the most significant vertebrate pests globally, because of their impacts on human and animal health. There are legal and moral obligations to minimise the impacts of wildlife management on animal welfare, yet there are few data on the relative welfare impacts of rat trapping and baiting methods used in the UK with which to inform management decisions. Two stakeholder workshops were facilitated to assess the relative welfare impacts of six lethal rat management methods using a welfare assessment model. Fifteen stakeholders including experts in wildlife management, rodent management, rodent biology, animal welfare science, and veterinary science and medicine, participated. The greatest welfare impacts were associated with three baiting methods, anticoagulants, cholecalciferol and non-toxic cellulose baits (severe to extreme impact for days), and with capture on a glue trap (extreme for hours) with concussive killing (mild to moderate for seconds to minutes); these methods should be considered last resorts from a welfare perspective. Lower impacts were associated with cage trapping (moderate to severe for hours) with concussive killing (moderate for minutes). The impact of snap trapping was highly variable (no impact to extreme for seconds to minutes). Snap traps should be regulated and tested to identify those that cause rapid unconsciousness; such traps might represent the most welfare-friendly option assessed for killing rats. Our results can be used to integrate consideration of rat welfare alongside other factors, including cost, efficacy, safety, non-target animal welfare and public acceptability when selecting management methods. We also highlight ways of reducing welfare impacts and areas where more data are needed.

Conditions for Investment in Genetic Biocontrol of Pest Vertebrates in Australia

Managing pest vertebrate species in Australia is a significant challenge for government, industry, research sectors and land-managers. Innovative tools such as genetic biocontrol offers decision-makers a potentially effective means of reducing the impact of pest species incursions. To determine the conditions for investment in genetic biocontrol, we applied qualitative engagement methodologies to identify and integrate existing knowledge of pest species research and management in Australia. Two facilitated workshops were held to determine key topics related to genetic biocontrol technologies for selected pest species. The topics explored during workshop discussions included: identifying existing knowledge gaps; risk perceptions; social and ethical considerations and; industry and business considerations. The workshops' aim was to assess the potential, the priorities and the risk parameters among expert stakeholders and decision-makers for using genetic biocontrol approaches to reduce the impacts of key pest species in Australia. This paper reports on the design, process and outcomes of each workshop to inform the creation of a decision framework. Stakeholders were cautiously optimistic of pursuing continued research and development for vertebrate pest management in Australia. However, employing an appropriate, transparent process for incorporating diverse stakeholder perspectives on genetic biocontrol technologies is essential to ensure their development and use remains supported. This outcome will require meaningful investment in both social science investigations and well-considered engagement processes concurrent with biotechnology development globally.

Gene drives for vertebrate pest control: Realistic spatial modelling of eradication probabilities and times for island mouse populations.

Invasive alien species continue to threaten global biodiversity. CRISPR‐based gene drives, which can theoretically spread through populations despite imparting a fitness cost, could be used to suppress or eradicate pest populations. We develop an individual‐based, spatially explicit, stochastic model to simulate the ability of CRISPR‐based homing and X chromosome shredding drives to eradicate populations of invasive house mice (Mus muculus) from islands. Using the model, we explore the interactive effect of the efficiency of the drive constructs and the spatial ecology of the target population on the outcome of a gene‐drive release. We also consider the impact of polyandrous mating and sperm competition, which could compromise the efficacy of some gene‐drive strategies. Our results show that both drive strategies could be used to eradicate large populations of mice. Whereas parameters related to drive efficiency and demography strongly influence drive performance, we find that sperm competition following polyandrous mating is unlikely to impact the outcome of an eradication effort substantially. Assumptions regarding the spatial ecology of mice influenced the probability of and time required for eradication, with short‐range dispersal capacities and limited mate‐search areas producing ‘chase’ dynamics across the island characterized by cycles of local extinction and recolonization by mice. We also show that highly efficient drives are not always optimal, when dispersal and mate‐search capabilities are low. Rapid local population suppression around the introduction sites can cause loss of the gene drive before it can spread to the entire island. We conclude that, although the design of efficient gene drives is undoubtedly critical, accurate data on the spatial ecology of target species are critical for predicting the result of a gene‐drive release.

Evaluation of oral baits and distribution methods for Tasmanian devils (Sarcophilus harrisii)†

Context Diseases are increasingly contributing to wildlife population declines. Tasmanian devil (Sarcophilus harrisii) populations have locally declined by 82%, largely owing to the morbidity and mortality associated with two independent transmissible devil facial tumours (DFT1 and DFT2). Toxic baits are often used as a management tool for controlling vertebrate pest populations in Australia, but in other areas of the world, oral baits are also used to deliver vaccines or pharmaceuticals to wildlife. Aim Our goal was to evaluate the potential use of edible baits as vehicles for vaccine delivery to Tasmanian devils. Method We first tested bait palatability with captive devils. Bait interactions were recorded, and consumption and bait interaction behaviours were quantified. We next trialled baits containing inert capsules as potential vaccine containers in captivity. After confirming bait palatability in captivity, ground baiting was trialled at six field sites and monitored using camera traps. Finally, an automated bait dispenser was trialled at field sites to attempt to limit bait consumption by non-target species. Key results Captive devils consumed all types of placebo baits, but consumed a higher percentage of ruminant- and fish-based baits than cereal-based baits. Captive devils also consumed inert capsules inserted into placebo baits. Ground-baiting trials in the field showed that 53% of baits were removed from bait stations, with 76% of the removals occurring on the first night. Devils were suspected or confirmed to remove about 7% of baits compared with 93% by non-target species. We also evaluated an automated bait dispenser, which reduced bait removal by non-target species and resulted in over 50% of the baits being removed by devils. Conclusions This study demonstrated that captive and wild devils will accept and consume placebo versions of commercial baits. Bait dispensers or modified baits or baiting strategies are needed to increase bait uptake by devils. Implications Bait dispensers can be used at a regional scale to deliver baits to devils. These could potentially be used as vaccine-delivery vehicles to mitigate the impacts of disease on devil populations.

The status of fertility control for rodents-recent achievements and future directions.

Management of overabundant rodents at a landscape scale is complex but often required to sustainably reduce rodent abundance below damage thresholds. Current conventional techniques such as poisoning are not species specific, with some approaches becoming increasingly unacceptable to the general public. Fertility control, first proposed for vertebrate pest management over 5 decades ago, has gained public acceptance because it is perceived as a potentially more species-specific and humane approach compared with many lethal methods. An ideal fertility control agent needs to induce infertility across one or more breeding seasons, be easily delivered to an appropriate proportion of the population, be species specific with minimal side-effects (behavioral or social structure changes), and be environmentally benign and cost effective. To date, effective fertility control of rodents has not been demonstrated at landscape scales and very few products have achieved registration. Reproductive targets for fertility control include disrupting the hormonal feedback associated with the hypothalamic-pituitary-gonadal axis, gonad function, fertilization, and/or early implantation. We review progress on the oral delivery of various agents for which laboratory studies have demonstrated efficacy in females and/or males and synthesize progress with the development and/or use of synthetic steroids, plant extracts, ovarian specific peptides, and immunocontraceptive vaccines. There are promising results for field application of synthetic steroids (levonorgestrel, quinestrol), chemosterilants (4-vinylcyclohexene diepoxide), and some plant extracts (triptolide). For most fertility control agents, more research is essential to enable their efficient and cost-effective delivery such that rodent impacts at a population level are mitigated and food security is improved.

In defence of the world’s most reviled vertebrate animals: part 1: ‘lower’ species (sharks, snakes, vultures, frogs & toads)

ABSTRACT Biodiversity is vital to the welfare and survival of humans, but public support for conservation of most animal species is appallingly limited. Vertebrates make up less than 5% of the world’s documented animal species, but are viewed far more sympathetically than invertebrates. This is because humans are empathetic with the appearance and behaviour of many of them, particularly the charismatic superstars like pandas and tigers that currently are the mainstays of biodiversity fundraising. Conversely, just as such attractive icons are effective ambassadors of biodiversity conservation, so certain detested and sometimes dangerous vertebrate pests have greatly compromised the public image of biodiversity. Some of these species, admittedly, are responsible for significant damage to health and economic welfare. Nevertheless, this paper shows that all play important ecological roles, they have compensating economic values, their harm has often been exaggerated, and their very negative public images are undeserved. This first installment deals with the most reviled ‘lower’ vertebrate species: sharks (representing fish); frogs and toads (representing amphibians); snakes (representing reptiles); and vultures (representing birds). The next contribution will deal with mammals.

Indigenous plant protection practices of Tripura, India

BackgroundTraditional plant protection strategies have an integral part of food production system in North Eastern state Tripura, India, which has bestowed with rich heritage and biodiversity. However, there is no comprehensive report on the indigenous plant protection practices (IPPPs) specific to insect and vertebrate pest management, being followed by the inhabitants of the region for centuries. The present study was conducted to investigate, collect, and document the vulnerable IPPP practices followed by the native people from far flung locations of the Tripura.MethodsThe study aimed to document the IPPP following semi-structured questionnaires, participatory interaction, and direct observations with a total of 200 informants. We have calculated the relative frequencies of citation (RFC) for IPPP and estimated principal component analysis to link the status of IPPP with socio-demographic factors of the informants. The relationship between the field of IPPP used and different covariates (age, education, occupation, gender, location, and house type) was assessed using the Kruskal–Wallis test and Chi-square test. The relationship between adoption level and the respondents’ characteristics was analyzed using count regression analysis.ResultsThe study found that the status of the IPPP has increased for mitigating pest issues. A total of 39 indigenous practices were recorded specifically to pest management from the ethnic people of Tripura, India. People acquired pretty knowledge about IPPP, and these were inherited from ancestors. The respondents in the study developed notable innovations for the management of many pest issues using locally available resources that warrant cost-effective and eco-friendly. Seed drying before storage to protect grain commodities was the most cited IPPP with a frequency of citation 0.675. In the field of IPPP used, the people primarily practiced agriculture + horticulture + storage category. An important implication from the study is the identification of two IPPP strategies in this region for the first time. Furthermore, the recorded IPPP used field was significantly associated with age, education, occupation, gender, locality, and house type. Likewise, the respondents’ socio-demographic variables were coupled considerably with the adoption of specific IPPP.ConclusionThe reported IPPP for alleviating pest problems reflects the wisdom and generosity of the ethnic growers of Tripura, India. The study suggests the IPPP has strong potential in an integrated pest management approach passed down from generation to generation. The vulnerable practices largely remained unexplored due to inadequate scientific scrutiny and authenticity, yet in danger of being lost if not documented systematically. This study provides the first step toward accessing the valuable technology of untapped Tripura in IPPP and could be viable in paving action paradigm for their preservation, diffusion, and application with advanced pest management options.

Contemporary challenges and opportunities for the management of bird damage at field crop establishment

Bird damage, from sowing to crop establishment, is an important issue for farmers in many parts of the world. However, reliable and cost-effective solutions remain elusive because management tools and research on the subject are limited. The spatial variability of damage across landscapes and the adaptative behaviour of birds create further challenges. Additionally, the issue must be tackled at the landscape scale and involve a variety of stakeholders with conflicting interests and objectives. We summarize some of the challenges and opportunities identified to face these difficulties and address four major research directions for operational solutions including 1) crop damage assessment, 2) methods and tools development at the landscape scale, 3) coordination of stakeholders, and 4) pest bird ecology in agroecosystems. More fundamentally, we address the question of large-scale ecological dynamics that can explain changing damage patterns such as the recent observations of increased damage in Europe. Despite the impact to the agricultural sector, research effort to understand vertebrate pest damage is still modest. We advocate for the creation of networks to share knowledge and feedback and engages multiple stakeholders, including ecological and agricultural researchers, farmers, and policy makers.

Building Bear Fences for Your Apiary


 
 
 
 
 
 
 The American black bear is beloved, but it is also the most damaging vertebrate pest of honey bee apiaries in North America. That is in part because bears and beekeepers often share the same home territory. Many top beekeeping and pollination states also fall within the range of the American black bear. Can bears and beekeepers live in peace together? This 6-page fact sheet written by Kimberly K. Post and Cameron Jack and published by the UF/IFAS Entomology and Nematology Department details the basic steps for installing an electrified bear fence around a bee yard so that savvy beekeepers can protect hives and honey without harming honey-loving bears.
 
 
 
 
 
 

Post-emergence seedling damage due to vertebrate pests and its impact on soybean establishment.

The quality of field crop establishment is an indicator of the productivity and yield quality of a given crop. Several biotic and abiotic factors, as well as cropping practices, affect the quality of field crop establishment. More specifically to soybean, recent studies quantified pre-emergence seedling losses and identified the associated causes of non-emergence. However, little is known about post-emergence seedling damage, mainly due to vertebrate pests, which represent an important problem for growers. A 2-year field observation was conducted to quantify near- and post-emergence seedling damage due to vertebrate pests. The common wood pigeon (Columba palumbus) and the European hare (Lepus europaeus) were associated with this kind of damage. The characteristic damage due to the common wood pigeon consisted of either partially-damaged cotyledons during emergence or completely uprooted seedlings at emergence. In contrast, damage due to the European hare consisted of chewed seedling or seedling parts. There was significant effect of year (p < 0.001) on the final rates of post-emergence seedling damage due to the wood pigeon but not on those due to the European hare. The final rates of post-emergence damage due to the wood pigeon were higher (32% for 2018 and 22% for 2020) compared with those owing to the European hare (18% for 2018 and 17% for 2020). The severity of damage due to vertebrate pests was related to the type of seedling damage that, in turn, affected the capacity of soybean to compensate for post-emergence seedling damage.

Effects of habitat on prey delivery rate and prey species composition of breeding barn owls in winegrape vineyards

The provision of habitat for natural enemies of agricultural pests is common in integrated pest management approaches but has rarely been examined for vertebrate predators controlling vertebrate pests. To mitigate the economic and environmental costs of removing rodent pests in vineyards in Napa Valley, California, winegrape producers have installed nest boxes to attract American barn owls (Tyto furcata) to their properties. A rigorous estimate of how many rodents barn owls remove from the landscape is a necessary first step to understanding the overall impact of barn owls on rodent pest populations, and this study provides an estimate of rodent removal and prey composition by using remote nest box cameras. In addition, we tested hypotheses for how habitat may influence prey delivery rates and composition. Videography indicated that each barn owl chick received on average of 191 ± 10.01 prey items before fledging the nest box and that the amount of grassland habitat near the nest box and the proportion of deliveries of smaller prey were positive predictors of prey delivery rate. Prey composition was dominated by voles, gophers, and mice, and their relative proportions were associated with the composition of habitats near a nest box. Specifically, oak savannah was positively associated with the proportion of gophers and negatively associated with voles, and grassland was positively associated with voles. Further research on prey delivery should focus on the possible roles of rodent abundance, adult owl quality, and additional metrics of habitat structure.

Continental threat: How many common carp (Cyprinus carpio) are there in Australia?

Common carp (Cyprinus carpio) are one of the world's most destructive vertebrate pests. In Australia, they dominate many aquatic ecosystems causing a severe threat to aquatic plants, invertebrates, water quality, native fish and social amenity. The Australian Government is considering release of cyprinid herpesvirus-3 (CyHV-3) as a control measure and consequently a robust, continental-scale estimate of the carp population and biomass is essential to inform planning and risk management. Here, we pioneer a novel model-based approach to provide the first estimate of carp density (no/ha) and biomass density (kg/ha) at river reach/waterbody, basin and continental scales. We built a spatial layer of rivers and waterbodies, classified aquatic habitats and calculated the area of each throughout the range of carp in Australia. We then developed a database of fishery-independent electrofishing catch-per-unit-effort (CPUE) for habitat types, containing catch information for 574,145 carp caught at 4831 sites. Eastern Australia accounted for 96% of carp biomass and 92% of the total available wetted habitat area (16,686 km2) was occupied. To correct these data for variable detection efficiencies, we used existing electrofishing data and undertook additional field experiments to establish relationships between relative and absolute abundances. We then scaled-up site-based estimates to habitat types to generate continental estimates. The number of carp was estimated at 199.2 M (95%Crl: 106 M to 357.6 M) for an ‘average’ hydrological scenario and 357.5 M (95%Crl: 178.9 M to 685.1 M) for a ‘wet’ hydrological scenario. In eastern Australia, these numbers correspond with biomasses of 205,774 t (95%Crl: 117,532–356,482 t) (average scenario) and 368,357 t (95%Crl: 184,234–705,630 t) (wet scenario). At a continental scale the total biomass was estimated at 215,456 t for an ‘average’ hydrological scenario. Perennial lowland rivers had the highest CPUE and greatest biomass density (up to 826 kg/ha) and the modelled biomass exceeded a density-impact threshold of 80–100 kg/ha in 54% of wetlands and 97% of stream area in large lowland rivers. The continental-scale biomass estimates provide a baseline for focusing national conservation strategies to reduce carp populations below thresholds needed to restore aquatic ecosystems at a range of spatial scales.

Viruses for Landscape-Scale Therapy: Biological Control of Rabbits in Australia.

Viral diseases, whether of animals or humans, are normally considered as problems to be managed. However, in Australia, two viruses have been used as landscape-scale therapeutics to control European rabbits (Oryctolagus cuniculus), the preeminent invasive vertebrate pest species. Rabbits have caused major environmental and agricultural losses and contributed to extinction of native species. It was not until the introduction of Myxoma virus that effective control of this pest was obtained at a continental scale. Subsequent coevolution of rabbit and virus saw a gradual reduction in the effectiveness of biological control that was partially ameliorated by the introduction of the European rabbit flea to act as an additional vector for the virus. In 1995, a completely different virus, Rabbit hemorrhagic disease virus (RHDV), escaped from testing and spread through the Australian rabbit population and again significantly reduced rabbit numbers and environmental impacts. The evolutionary pressures on this virus appear to be producing quite different outcomes to those that occurred with myxoma virus and the emergence and invasion of a novel genotype of RHDV in 2014 have further augmented control. Molecular studies on myxoma virus have demonstrated multiple proteins that manipulate the host innate and adaptive immune response; however the molecular basis of virus attenuation and reversion to virulence are not yet understood.

Social Context Influence on Urban Gardener Perceptions of Pests and Management Practices

Community gardens are important urban green spaces with a variety of social and ecological benefits, one of which is access to healthy food. Similar to rural agriculture, the quantity and quality of the food produced can be compromised by pest damage. In fact, many urban gardeners report crop damages caused by vertebrate and invertebrate pests. Yet, because the food produced in community gardens is mostly for self-consumption and thus not under market quality standards, the damage thresholds and the point when gardeners perceive a pest problem and how they decide to manage it, may greatly vary from gardener to gardener. Here, we investigated how socio-demographic factors and experience affect whether gardeners report having a pest problem and which pest management practices they use. We surveyed 187 gardeners from 18 different urban community gardens in three counties in the California central coast, USA. We also collected information about gardener socio-demographic factors (age, gender, ethnicity), as well as education, and years of experience in agriculture. The majority of gardeners reported having pests in their plots but their ethnicity, the amount of time they spend in the gardens, and whether they work in agricultural-related employment or not influenced the likelihood of reporting pests. We found that the majority of gardeners use curative, non-synthetic practices for managing pests, but that some use preventive practices and some don’t do anything to control pests. The likelihood of using practices that are curative depended on gardeners’ ethnicity, the amount of time they spend in the gardeners, and their gender. Our results suggest that the agricultural knowledge of urban community gardeners and the practices they use varies greatly and that, in order to be successful, extension programs may need to take this diversity into account when promoting the agroecological paradigm in urban agricultural systems.

Progress Toward Zygotic and Germline Gene Drives in Mice.

CRISPR-based synthetic gene drives have the potential to deliver a more effective and humane method of invasive vertebrate pest control than current strategies. Relatively efficient CRISPR gene drive systems have been developed in insects and yeast but not in mammals. Here, we investigated the efficiency of CRISPR-Cas9-based gene drives in Mus musculus by constructing "split drive" systems where gRNA expression occurs on a separate chromosome to Cas9, which is under the control of either a zygotic (CAG) or germline (Vasa) promoter. While both systems generated double-strand breaks at their intended target site in vivo, no homology-directed repair between chromosomes ("homing") was detectable. Our data indicate that robust and specific Cas9 expression during meiosis is a critical requirement for the generation of efficient CRISPR-based synthetic gene drives in rodents.