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Invasive rats are one of the world's most successful animal groups that cause native species extinctions and ecosystem change, particularly on islands. On large islands, rat eradication is often impossible and population control, defined as the local limitation of rat abundance, is now routinely performed on many of the world's islands as an alternative management tool. However, a synthesis of the motivations, techniques, costs, and outcomes of such rat-control projects is lacking. We reviewed the literature, searched relevant websites, and conducted a survey via a questionnaire to synthesize the available information on rat-control projects in island natural areas worldwide to improve rat management and native species conservation. Data were collected from 136 projects conducted over the last 40 years; most were located in Australasia (46%) and the tropical Pacific (25%) in forest ecosystems (65%) and coastal strands (22%). Most of the projects targeted Rattus rattus and most (82%) were aimed at protecting birds and endangered ecosystems. Poisoning (35%) and a combination of trapping and poisoning (42%) were the most common methods. Poisoning allows for treatment of larger areas, and poison projects generally last longer than trapping projects. Second-generation anticoagulants (mainly brodifacoum and bromadiolone) were used most often. The median annual cost for rat-control projects was US$17,262 or US$227/ha. Median project duration was 4 years. For 58% of the projects, rat population reduction was reported, and 51% of projects showed evidence of positive effects on biodiversity. Our data were from few countries, revealing the need to expand rat-control distribution especially in some biodiversity hotspots. Improvement in control methods is needed as is regular monitoring to assess short- and long-term effectiveness of rat-control. Las ratas invasoras son uno de los grupos animales más exitosos a nivel mundial que ocasionan la extinción de especies nativas y cambios en los ecosistemas, particularmente en las islas. En las islas grandes, la erradicación de las ratas es generalmente imposible y el control de población, definido como la limitación local de la abundancia de ratas, hoy en día se practica rutinariamente en muchas de las islas del mundo como una herramienta alternativa de manejo. Sin embargo, se carece de una síntesis de motivaciones, técnicas, costos y resultados de dichos proyectos de control de ratas. Revisamos la literatura, buscamos sitios web relevantes, y realizamos una encuesta por medio de un cuestionario para sintetizar la información disponible sobre los proyectos de control de ratas en las áreas naturales isleñas en todo el mundo para así mejorar el manejo de ratas y la conservación de especies nativas. Se recolectaron datos de 136 proyectos que se realizaron en los últimos 40 años; la mayoría se ubicaron en Australasia (46 %) y el Pacífico tropical (25 %) en ecosistemas boscosos (65 %) y franjas costeras (22 %). La mayoría de los proyectos estaban enfocados en Rattus rattus, y la mayoría (82 %) estaban centrados en la protección de aves y ecosistemas en peligro de extinción. Los métodos más comunes fueron el envenenamiento (35 %) y una combinación de trampas y veneno (42 %). El envenenamiento permite tratar con áreas más grandes y generalmente dura más tiempo que el trampeo. Los anti-coagulantes de segunda generación (principalmente el brodifacoum y la briomadiolona) fueron los más usados. El costo medio anual de los proyectos de control de ratas fue de US$17,262 o de US$227/ha. La duración media de los proyectos fue de cuatro años. Para el 58 % de los proyectos, se reportó una reducción en la población de ratas, y el 51 % de los proyectos mostró evidencias de un efecto positivo sobre la biodiversidad. Nuestros datos provienen de pocos países, lo que revela la necesidad de expandir la distribución del control de ratas, especialmente en algunos puntos calientes de biodiversidad. Se necesita mejorar los métodos del control, así como un monitoreo regular para evaluar la efectividad del control de ratas a corto y largo plazo.

This work reviews the historical and current pest risks and research concerning seed storage in the Czech Republic (CR). Stored seed pests (i.e. animals causing injuries to the germ and endosperm) represent a high risk of economic damage due to the high value of seeds coupled with long-term seed storage in small storage units (e.g., boxes, satchels). Rodents represent a significant risk to all types of seeds, especially seeds stored in piles or bags. Mites, psocids, and moths are the main pests of stored grass and vegetable seeds: mites can decrease seed germinability by 52% and psocids caused 9.7% seed weight loss in broken wheat kernels after 3 months of infestation under laboratory conditions. Although beetles (Sitophilus sp., Tribolium sp., Oryzaephilus sp.) and moths (Plodia sp.) are common pests of grain seeds (e.g., wheat, barley, maize), two serious seed pests, Sitotroga cereallela and S. zemays, are rare in the CR. Bruchus pisorum is a common pest of pea seeds, while other Bruchids are rare in the Czech legume seed stores. Currently, the control of seed pests is becoming difficult because the efficient pesticides (e.g., methylbromide, dichlorvos, drinking anticoagulant rodent baits) for seed protection have been lost without the development of adequate substitutes. New research on seed protection in the CR using biological control (mite predators Cheyletus sp.), low pressure, modified atmospheres, and hydrogen cyanide is overviewed.

The role of predators in the integrated protection of agricultural crops is highly important. An example may be found in the use of bird predators for vole control by artificially boosting their aggregations through installation of artificial perches. The dependence of raptor density in the period following nesting (summer through to autumn) on vole abundance in the presence and absence of artificial perches was studied using the method of belt transect. The research was conducted in field biotopes of cultivated sugar beet in the beet-production area of the Olomouc region. Presented research results have revealed that artificial perches installed in sugar beet plantations increase the efficiency of raptor predation pressure on the target pest species up to six times. It is quite obvious that this method of biological control of the common vole may yield significant results in the integrated pest control in sugar beet.

A study was conducted in western Montana to determine the impact of different predators on grasshopper populations. By placing grasshoppers of different species, sexes, ages, and body masses on monofilament tethers in the field, rates of predation could be estimated. These rates are consistent with other estimates obtained from population studies in the same environment, but provide a far more detailed assessment of which grasshoppers are most vulnerable to predators and which predators are most important. Immature individuals are more vulnerable at small body sizes and adults are more vulnerable at large body sizes; this is because the principal predators on immature individuals are arthropods, and on adults, vertebrates. Male grasshoppers were 2-3 times as vulnerable as females. The subfamily Oedopodinae was more vulnerable than the Gomphocerinae or Melanoplinae. Predation rates indicate that predators are only able to impact seriously (reduce life expectancy below the suitable abiotic period for existence) the largest Oedopodinae, making predation of little consequence for most grasshopper populations in this environment.

Sugarcane growers in Hawaii suffer crop damage and sugar losses to rats (Rattus spp.). We conducted tests to evaluate commercial zinc phosphide baits for reducing rat populations in Hawaiian sugarcane fields. During laboratory bioassays, mortality of black rats (R. rattus) and Polynesian rats (R. exulans) was higher (P < 0.05) with KFE Zinc Phosphide Prepared-Rat Bait and Hopkins Zinc Phosphide Pellets than with ZP Rodent Bait AG or Ridall-Zinc Rodent Field and Agricultural Bait. Hopkins Zinc Phosphide Pellets was the most effective (P < 0.05) bait against Norway rats (R. norvegicus), but low mortality with even this bait (70%) indicates the effectiveness of field applications may be variable. Single aerial broadcast applications of HGP Zincphos Oats or Hopkins pellets did not reduce (P > 0.05) the number of rats captured in sugarcane fields. Prebaiting with nontoxic grain according to manufacturers' instructions enhanced (P < 0.05) effectiveness of zinc phosphide oat bait, but not zinc phosphide pelleted bait (P > 0.05). However, substantial numbers of rats remained in all fields, regardless of rodenticide or whether fields were prebaited with nontoxic grain. Absorption of moisture and physical degradation may have reduced rats' acceptance of pellets. A more weather-resistant bait is needed to control rat depredations in wet and humid areas.

This study was designed to test the hypothesis that large-scale provision of diversionary food (sunflower seeds) would reduce red squirrel (Tamiasciurus hudsonicus) feeding damage to lodgepole pine (Pinus contorta) crop trees. Study areas with managed lodgepole pine stands were located near Vernon and Quesnel in south-central British Columbia, Canada. Large-scale applications of sunflower seeds were conducted on a manual basis in 1989, and by manual and aerial means in 1990, and an operational level by aerial means in 1991. Feeding damage to crop trees was assessed in control and treatment blocks. Populations of the red squirrel, northwestern chipmunk (Eutamias amoenus), and Columbian ground squirrel (Spermophilus columbianus) were sampled intensively by live-trapping on control and treatment blocks in 1990. Manual application of seed (clumped distribution) significantly reduced damage in the treatment block (11.3% of trees damaged) compared with the control (57.5% of trees damaged). Aerial application of seed (uniform distribution) also significantly reduced damage in replicated treatment vs. control blocks. Provision of diversionary food resulted in a temporary increase in the overall number of red squirrels caught on the treatment areas followed by a return to control levels within 6 wk. This increase was primarily the result of an increased number of transients in the trapped sample. The population density of resident (transients excluded) red squirrels did not increase when diversionary food was added. Similarly, we could not detect differences in reproduction, body masses, or survival of squirrels between control and food-supplemented areas. Northwestern chipmunks and Columbian ground squirrels also showed a temporary increase in density when food was added. Application of sunflower seed on an operational basis significantly reduced damage by squirrels in replicated study areas covering three different forest ecological zones. Provision of diversionary food is an effective strategy to protect intensively managed stands of lodgepole pine from red squirrel feeding damage.

Two indirect measures of pocket gopher activity have been widely applied, the open-hole method and the plot-occupancy or mound-count method. These methods and two plot sizes are compared. In each case, the open-hole measurement detected more positive results than the plot-occupancy measurement.