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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 effects of grazing by white-tailed deer (Odocoileus virginianus) on populations of Trillium spp. were examined in remnant, old-growth patches of the highly fragmented Big Woods forest ecosystem in southeastern Minnesota. We conducted three separate studies involving an exclosure experiment, transplant experiments, and comparisons of Trillium populations among study sites. The highest grazing intensity was observed where deer occurred at high overwinter concentrations (∼ 25-35/km2); significantly lower grazing intensities occurred at low overwinter density (∼ 5-10/km2). Deer focused their grazing on large, reproductive plants; at sites with high deer density, Trillium population structure was skewed toward small plants, and deer consistently caused over 50% reduction in reproduction during the growing season. Protection of individual plants from deer for two growing seasons resulted in dramatically increased flowering rates and significantly greater leaf area compared to control plants. No significant impact of current-year herbivory on reproduction in the following year was detected. Nevertheless, flowering rates at one site with high overwinter deer densities for at least the past 5 years suggest that the cumulative effects of grazing over several years can reduce reproduction in subsequent years. Transplant experiments with Trillium grandiflorum also showed that deer had significant effects on growth and reproduction where deer occur at high density. Our results suggest that changes in landscape structure and local deer abundance have altered plant-deer relationships such that grazing can lead to the local extirpation of sensitive forbs such as Trillium spp. As a result, active, long-term management of deer at low densities appears necessary for the conservation and restoration of fragmented forest communities in eastern North America.

Monitoring of species spectrum of true bugs (Heteroptera) on apple trees without pest management was conducted in 2010-2011. Two sites were selected - an abandoned orchard and a road alley near the village of Velke Bilovice (Breclav district, Czech Republic). The capture of true bugs with a fogger device (Pulsfog) on five selected trees in each site was performed. The effective substance deltamethrin at concentration of 0.0025 g/L was applied to the tree crowns. Three collections (28/4, 20/5, and 9/7) in 2010 and two (11/5 and 23/6) in 2011 were done. Out of 55 detected species of true bugs, 43 species occurred in the alley and 29 in the orchard. Thirty-two species were predatory or partly predatory (58.18%), 22 species were phytophagous (40%), and one mycetophagous (1.82%).

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.

We argue that generalist natural enemies of herbivorous insects provide a major selection pressure for restricted host plant range. The significance of plant chemistry is discussed in terms of regulating behavior, while the chemical coevolutionary theories are considered to be of limited value.

We used a predator removal experiment to examine the role of red fox (Vulpes vulpes) predation in suppressing rabbit (Oryctolagus cuniculus) population growth in Namadgi National Park in southeastern Australia. At 2 sites, fox abundance was reduced with a 1080 poisoning campaign maintained over 18 months. The responses of rabbit populations in these fox-reduced sites were compared to 2 other sites where fox populations remained intact. In the 2 removal sites, rabbit populations grew to 6.5 and 12.0 times their initial population size within 18 months. In the untreated sites, rabbit populations showed very small population increases over the same period. The experiment demonstrated that 1 introduced pest species suppressed the population growth of another pest species. As fox removal was initially planned to protect native fauna threatened by fox predation, the response of the rabbits represents a serious ecological cost of fox control.

We radiotracked 95 white-tailed deer (Odocoileus virginianus, all age classes) in Michigan's Upper Peninsula between January 1992 and January 1995 for a total of 38,888 deer-days. Fifty-eight deer died: 12 due to predation, 6 due to malnutrition, 14 due to other or unknown sources, and 26 killed by hunters (including 1 that was poached). Analysis of mortality indicated rates of annual nonhunting mortality were 0.19 (SE = 0.09) for adult females, 0.00 (SE = 0.05) for adult males and yearling females, and 0.16 (SE = 0.07) for yearling males. Hunting mortality was 0.04 (SE = 0.10) for adult females, 0.72 (SE = 0.12) for adult males, 0.12 (SE = 0.09) for yearling females, and 0.47 (SE = 0.10) for yearling males. Hunting mortality was higher among males in both age classes (P < 0.01) though nonhunting mortality was equivalent (P ≥ 0.05). Seasonal mortality rates of males and females differed during the fall (P < 0.001), coincident with Michigan's hunting seasons. Hunting mortality was significantly higher for yearling and adult males due to hunting regulations that limited harvest of antlerless deer; consequently, adult sex ratios were skewed towards females.

We evaluated the effectiveness of Flight Control™ (FC), which contains 50% anthraquinone (AQ), as a grazing repellent for Canada geese (Branta canadensis) and as a seed-treatment repellent for brown-headed cowbirds (Molothrus ater) in northern Ohio in 1997. For the turf test, FC was applied at 4.5 L/ha in 6 18.3- × 30.5-m pens. There were 2.5 times more (P < 0.01) bill contacts/min observed on untreated plots (26.4 ± 6.0; x̄ ± SE) compared to treated plots (10.4 ± 3.8) during a 7-day test with captive geese. Mean numbers of geese per observation were also greater (P = 0.02) on untreated plots (2.6 ± 0.4) compared to treated plots (1.4 ± 0.4). Residue analyses indicated AQ declined from 2.02 kg/ha at application to 0.22 kg/ha after 1 week. Individually caged cowbirds were presented untreated millet or millet treated with FC at 0.1, 0.5 and 1.0% (g/g) levels in 1- and 2-choice tests for 3-4 days. Flight Flight Control™ was repellent to cowbirds at all levels in both 1- and 2-choice tests. In the 2-choice test, birds in the 1.0% treatment level lost body mass (P = 0.04), whereas birds at the other levels did not. Each group of treated birds in the 1-choice test lost mass (P ≤ 0.01), whereas the control group did not. Birds in the 0.5 and 1.0% groups ate minimal amounts; 3 of 12 birds died. We conclude that FC was an effective foraging repellent for Canada geese in a 7-day pen experiment and for brown-headed cowbirds as a seed repellent in aviary experiments. Flight Control™ shows promise as an avian feeding repellent. Further lab and field studies are needed to refine minimum repellent levels and to enhance retention of AQ on treated vegetation.

The use of hand-reared deer in foraging experiments is a common practice, but its validity as a technique for estimating wild deer behavior has often been questioned. We conducted 2 experiments to determine the influence of learning and experience on forage selection and foraging efficiency in white-tailed deer (Odocoileus virginianus). In the first experiment, we compared food selection (diet composition) and foraging efficiency (biting rate, bite size, and intake rate) among a group of adult hand-reared deer that had been used in previous field experiments (experienced adults), and 2 groups of fawns, one of which was weaned to a diet of 13 browses, a pelleted ration, and alfalfa hay (experienced fawns), the other weaned to pellets and hay alone (naive fawns). Each animal was offered an identical array of 6 browses varying in palatability in a series of 5 feeding trials. The naive fawns selected a diet similar to that of the experienced fawns and adults. The ordering of preferences of the 6 browses was not statistically different among the 3 groups of animals. Biting rates, bite sizes, and intake rates were not statistically different between naive and experienced fawns, although bite size and intake rates were generally greater for the adult animals. In a second experiment, we compared food selection and foraging efficiency of wild and hand-reared adult deer using a procedure similar to experiment 1. Food selection by tame and wild deer was similar except for a difference between groups for one of the lesser-preferred species of browse. Preference rankings of the 6 browses were not statistically different when preferences were ranked according to mass consumed or number of bites taken. We suggest that food selection by white-tailed deer is largely an innate behavior and that hand-reared deer are essentially the foraging equivalents of maternal-reared or wild animals.

Factors affecting the distribution of the grasses Spartina alterniflora and Distichlis spicata in a mid-Atlantic salt marsh were examined. A series of eight shallow wells, four in patches of each grass type, was used to describe physicochemical conditions known to limit the distribution of both grasses. Tidal amplitude, surface of subsurface salinity, and subsurface oxidation-reduction potential were found to be within range, but suboptimal, for both grasses. Evidence of selective grazing upon S. alterniflora was found through examination of grazing sign within the grass patches, observations of feral horse feeding behavior, and examination of feral horse feces for grass epidermal fragments. An exclosure experiment simulated preferential grazing and showed that S. alternifora responded negatively while D. spicata responded positively to simulated preferential grazing of S. alterniflora. These results point to a competitive relationship between the grasses under suboptimal conditions for dominance of either species. Selective herbivory (analogous to predation) upon S. alterniflora was shown to be a plausible factor impacting the competition relationship to favor D. spicata. Location along physical gradients, interspecies competition, and herbivory are discussed in relation to salt marsh plant communities.