Introduction, Recovery, and Limited Establishment of Coleophora klimeschiella (Lepidoptera: Coleophoridae) on Russian Thistles, Salsola australis, in Southern California

Although case-bearing leafmining larvae of Coleophora klimeschiella Toll were released on Russian thistles, Salsola australis R. Brown (Chenopodiaceae), at 13 locations in southern California during 1977-85, this biological control agent remained tenuously established at only one site by late 1986. Neither insectary-reared or field-collected stocks released in field cages or in the open in numbers of 100-600 per site appeared to foster colony establishment. Poor host-plant adaptation as well as predation and parasitism by indigenous natural enemies are identified as possible sources of biotic resistance to the establishment of this imported insect. The predator, Phylobacnus atriplexus (Foster) (Coleoptera: Cleridae), and the primary parasite, Macroneura sp. (Hymenoptera: Eupelmidae), found attacking C. klimeschiella, also are known from gall-midge hosts on native saltbushes (Atriplex spp., also Chenopodiaceae

Teaching Robust Argumentation Informed by the Nature of Science to Support Social Justice. Experiences from Two Projects in Lower Secondary Schools in Norway

Under embargo until: 2022-09-09This chapter suggests a set of design principles for science curricula that will enable students to produce evidence-based arguments expressing views related to their own interests. It is based on the assumption that the ability to construct evidence-based arguments strengthens students’ ability to promote their own views in the interest of social justice. This is of special importance for students not enculturated into such argumentation through their upbringing. To promote one’s own views in a debate means to critique others’ arguments, and especially to ensure one’s own arguments are resistent to criticism. Insight into the nature of science includes insights in how to construct sound arguments based on facts and research results. The discussion of design principles is based on an analysis of two science projects in two lower secondary schools in Norway (Grade 8). In the first project, students produced scientific claims based on evidence from their own practical experiments. In the second project, the students developed and applied a method for estimating energy use and carbon dioxide (CO2) emissions. The students used their findings to construct arguments related to local transport plans. The analysis focuses on challenges and successes in scaffolding students at different competence levels to successfully produce evidence-based arguments.acceptedVersio

Cancer risks from arsenic in drinking water.

Ingestion of arsenic, both from water supplies and medicinal preparations, is known to cause skin cancer. The evidence assessed here indicates that arsenic can also cause liver, lung, kidney, and bladder cancer and that the population cancer risks due to arsenic in U.S. water supplies may be comparable to those from environmental tobacco smoke and radon in homes. Large population studies in an area of Taiwan with high arsenic levels in well water (170-800 micrograms/L) were used to establish dose-response relationships between cancer risks and the concentration of inorganic arsenic naturally present in water supplies. It was estimated that at the current EPA standard of 50 micrograms/L, the lifetime risk of dying from cancer of the liver, lung, kidney, or bladder from drinking 1 L/day of water could be as high as 13 per 1000 persons. It has been estimated that more than 350,000 people in the United States may be supplied with water containing more than 50 micrograms/L arsenic, and more than 2.5 million people may be supplied with water with levels above 25 micrograms/L. For average arsenic levels and water consumption patterns in the United States, the risk estimate was around 1/1000. Although further research is needed to validate these findings, measures to reduce arsenic levels in water supplies should be considered

Host selection by an insect herbivore with spatially variable density dependence

Many species of phytophagous insects do not oviposit preferentially on plants that yield high offspring performance. One proposed explanation is that negatively density-dependent offspring performance would select for females that disperse eggs among plants to minimize competition. Recent work showing larval density dependence often varies substantially among plants suggests that ovipositing females should not only respond to the density of competitors but also to traits predictive of the strength of density dependence mediated by plants. In this study, we used field and greenhouse experiments to examine oviposition behavior in an insect herbivore that experiences density-dependent larval performance and variability in the strength of that density dependence among host-plant individuals. We found females moved readily among plants in the field and had strong preferences for plants that mediate weak offspring density dependence. Females, however, did not avoid plants with high densities of competitors, despite the fact that offspring performance declines steeply with density on most plants in natural populations. This means females minimize the effects of density dependence on their offspring by choosing plants that mediate only weak larval density dependence, not by choosing plants with low densities of competitors. Our results suggest that explaining the lack of positive preference-performance correlations in many systems may not be as simple as invoking density dependence. Resource selection behavior may depend not just on the presence or absence of density-dependent offspring performance but also on variation in the strength of offspring density dependence among sites within populations

The evolution of mating systems in bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae)

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72492/1/j.1096-3642.1983.tb00858.x.pd