Bug Hunting with False Negatives Revisited

Safe data abstractions are widely used for verification purposes. Positive verification results can be transferred from the abstract to the concrete system. When a property is violated in the abstract system, one still has to check whether a concrete violation scenario exists. However, even when the violation scenario is not reproducible in the concrete system (a false negative), it may still contain information on possible sources of bugs. Here, we propose a bug hunting framework based on abstract violation scenarios. We first extract a violation pattern from one abstract violation scenario. The violation pattern represents multiple abstract violation scenarios, increasing the chance that a corresponding concrete violation exists. Then, we look for a concrete violation that corresponds to the violation pattern by using constraint solving techniques. Finally, we define the class of counterexamples that we can handle and argue correctness of the proposed framework. Our method combines two formal techniques, model checking and constraint solving. Through an analysis of contracting and precise abstractions, we are able to integrate overapproximation by abstraction with concrete counterexample generation

Alfalfa Trap Cropping Increases Abundance Of Key Arachnids In An Organic Strawberry Agroecosystem

Eighty three percent of the strawberries consumed in North America are grown in California, where the widespread use of insecticides has become hazardous to public health. The intensive use of pesticides for growing strawberries causes serious health risks to farm workers, in addition to contaminating the soil and groundwater. The cost to the environment and public health in the United States is estimated at $12 billion annually. Finding effective nontoxic management strategies for insect pests has become essential for long term sustainability. One strategy strawberry producers can use to promote sustainability is to increase the effectiveness of biological control techniques. Field experiments in other crops suggest that arachnid diversity and abundance may provide such a role in controlling insect pests and that agroecosystem diversification can enhance arachnid populations. This study therefore evaluated the composition, abundance, and pest control potential of arachnid communities in an organic strawberry field in California. The study found that by integrating alfalfa trap crops into organic strawberries, arachnid populations were substantially increased. Results reflected substantial increases in both male and female arachnid populations in and near alfalfa strip crops, with spider and harvestman arachnid families increasing most dramatically. Preliminary data suggest that an increase in alfalfa trap crops may lead to a reduction of the primary strawberry insect pest, Lygus hesperus, which is consumed by arachnids. These results provide useful new information for California farmers

Insects - a mistake in God's creation? Tharu farmers' perception and knowledge of insects: A case study of Gobardiha Village Development Committee, Dang-Deukhuri, Nepal

Recent trends in agriculturalresearch and development emphasize the need forfarmer participation. Participation not onlymeans farmers' physical presence but also theuse of their knowledge and expertise.Understanding potentials and drawbacks of theirlocal knowledge system is a prerequisite forconstructive collaboration between farmers,scientists, and extension services.An ethnoentomological study, conducted in aTharu village in Nepal, documents farmers'qualitative and quantitative knowledge as wellas perceptions of insects and pest management,insect nomenclature and classification, andissues related to insect recognition and localbeliefs. The study offers a basis to improvepest management programs in terms of efficacyand acceptance. It demonstrates, for instance,that a concept of pests and beneficials isvirtually missing in traditional farmingcommunities and that the Tharu folkclassification profoundly differs from thescientific classification, but is not radicallydifferent from other folk entomologicalsystems. Insects belong to the taxa calledkiraa consisting of arthropods andnon-arthropods that interact with humans. Theyare classified in several overlappinghierarchies where locomotion and human impactplay major roles while morphological criteriaare almost irrelevant. Recognition ofkiraa, however, is dominated by agriculturalaspects followed by physiological-behavioral,ecological, and human-directed features.Morphological criteria play a minor role. Innomenclature, however, the insects' physicalappearance is more important than otherfeatures. The study further shows that male andfemale farmers have different perceptions ofkiraa.The insect-related knowledge system of theTharu has prevented farmers from using modernpesticides in the past. In the course ofmodernization, however, some aspects of theirknowledge system could become obsolete andprove disadvantageous to their livelihood andagro-ecosystem

Collectivized Intellectualism

We argue that the evolutionary function of reasoning is to allow us to secure more accurate beliefs and more effective intentions through collective deliberation. This sets our view apart both from traditional intellectualist accounts, which take the evolutionary function to be individual deliberation, and from interactionist accounts such as the one proposed by Mercier and Sperber, which agrees that the function of reasoning is collective but holds that it aims to disseminate, rather than come up with, accurate beliefs. We argue that our collectivized intellectualism offers the best explanation of the range of biases that human reasoning is prone to, and that it does better than interactionism at offering a function of reasoning that would have been adaptive for our distant ancestors who first evolved this capacity

South Carolina Wildlife, May-June 1981

The South Carolina Wildlife Magazines are published by the South Carolina Department of Natural Resources who are dedicated to educating citizens on the value, conservation, protection, and restoration of South Carolina's wildlife and natural resources. These magazines showcase the state’s natural resources and outdoor recreation opportunities by including articles and images of conservation, reflections and tales, field notes, recipes, and more. In this issue: Biosphere ; The Gift of an Oak ; Outdoor Ethics: Code for Survival ; Wild Plants: Ten for the Table ; The Port Royal Torpedo ; The Birds of Boykin Mill ; Bugging for Bass and Bream ; The Adaptable Bandit ; Oases Beneath the Sea ; Striking ; Readers' Forum ; Books and Events ; Field Trip ; Ramblings ; Roundtable

Observational Learning in the Jumping Spider \u3ci\u3ePhidippus audax\u3c/i\u3e

Observational learning is a complex form of learning most frequently studied in social vertebrates. However, evidence for social learning exists in several invertebrate species Evidence of invertebrate observational learning also exists, though to a lesser extent. This study addresses observational learning in a jumping spider (Phidippus audax) through video playback. My results suggest that while observational learning is occurring, the exact mechanism in use remains unclear. Spiders that saw a conspecific satiate itself on a prey item readily attacked a similar prey item when exposed to a live prey item. However, spiders exposed to a conspecific rejecting or in the absence of a prey item were much more cautious when exposed to a live prey item. While virtually all spiders did eventually attack, a significant increase was found in the latency to the attack. No other groups demonstrated deviated from the behavior of the control group. My data suggest that observational learning may be present in a more diverse array of taxa than is held in traditional views of social learning, including highly asocial invertebrates such as spiders. Advisor: Rick A. Bevin

Community level impacts of Microstegium vimineum on arthropod community structure and foodweb dynamics in a temperate deciduous forest.

Invasion by non-native primary producers are generally expected to lead to a decline in native species richness, however in some cases, these invasions can actually lead to an increase in diversity and abundance of certain groups of organisms. Arthropods are extremely sensitive to changes in the plant community, particularly herbivores, and the response of these primary consumers can influence predator populations. Microstegium vimineum is an invasive C4 grass that has developed strong populations in the understory of temperate deciduous forests along the east coast of the U.S. This work evaluates the influence that this invader may have on insect and spider abundance and diversity, including changes at the trophic group and functional guild levels. Additionally we evaluate the impacts of both an increase in invasion density and a decrease in native plant diversity on arthropod community structure. In general, we find a significant increase in herbivore abundance, primarily as a result in the increased abundances of concealed chewers, free-living chewers and free-living sap feeders. Free-living sap-feeders also showed an increase in biomass. Spider abundance and diversity also increased in association with invasion by M. vimineum. Both active hunters and sit-and-wait predators showed significant increases in invaded sites. The ratio of adult:immature spiders however had a negative relationship with invasion. These changes in the arthropod community appear to be related to both changes in vegetation structure as well as changes in plant biomass. We found increased abundances in our treatments in which invasion density increased and decreases in the arthropod community in sites where native plants were removed from the system. We also show some support for the idea that carnivores, specifically spiders, may respond more strongly to changes in vegetative complexity, while herbivores, specifically leaf hoppers, may respond more strongly to changes in plant biomass