How Do Students Critically Evaluate Outdated Language That Relates to Gender in Biology?

Cisheteronormative ideologies are infused into every aspect of society, including undergraduate science. We set out to identify the extent to which students can identify cisheteronormative language in biology textbooks by posing several hypothetical textbook questions and asking students to modify them to make the language more accurate (defined as "correct; precise; using language that applies to all people"). First, we confirmed that textbooks commonly use language that conflates or confuses sex and gender. We used this information to design two sample questions that used similar language. We examined what parts of the questions students modified, and the changes they recommended. When asked to modify sample textbook questions, we found the most common terms or words that students identified as inaccurate were related to infant gender identity. The most common modifications that students made were changing gender terms to sex terms. Students' decisions in this exercise differed little across three large biology courses or by exam performance. As the science community strives to promote inclusive classrooms and embrace the complexity of human gender identities, we provide foundational information about students' ability to notice and correct inaccurate language related to sex and gender in biology.

Co-occurrence Among Intraguild Predators: Avoidance or Aggregation?

Intraguild predation (IGP) may interact with prey availability to structure predator communities. However, if predators are able to avoid each other, its effect on predator community structure may be minimized or absent. To determine whether co-occurrence among IG predators is limited, we estimated co-occurrence among predators in experimental plots of maize and soybean. These crops provide high densities of shared resources (aphids) as well as known IG predators (primarily coccinellids). Despite documented intraspecific and interspecific avoidance behaviors, aggregation to patchy resources could bring IG predators into contact. We, therefore, hypothesized that despite documented intraspecific avoidance behaviors, aphidophagous IG coccinellid predators would not significantly avoid co-occurrence, making IGP likely. Co-occurrence was estimated from visual counts of aphid predators and their prey on randomly selected plants over the course of the growing season. For each habitat, we used maximum likelihood analysis to determine whether observed co-occurrence deviated significantly from that expected for each possible pairwise combination of IG predators. We repeated this analysis using published data on co-occurrence among aphid predators on tansy. We found that most co-occurrence among IG predators was random, suggesting that avoidance does not limit co-occurrence. Failure to limit co-occurrence could be the result of ineffective avoidance mechanisms or because predators balance aggregating on shared resources with avoiding IG predators.

Landscape Effects on Solenopsis invicta (Hymenoptera: Formicidae) and Geocoris spp. (Hemiptera: Geocoridae), Two Important Omnivorous Arthropod Taxa in Field Crops.

The economically important brown stink bug, Euschistus servus (Say) (Hemiptera: Pentatomidae), is a native pest of many crops in southeastern United States and insecticide applications are the prevailing method of population suppression. To elucidate biological control of E. servus populations, we investigated two egg predators' (red imported fire ants, Solenopsis invicta Buren (Hymenoptera: Formicidae), and Geocoris spp. (Hemiptera: Geocoridae)) responses to both local and landscape factors that may have influenced their combined ability to cause mortality in immature E. servus. We estimated the density of fire ants and Geocoris spp. on four major crop hosts-maize, peanut, cotton, and soybean-in 16 landscapes over 3 yr in the coastal plain of Georgia, USA. Both Geocoris spp. and fire ant populations were concentrated on specific crops in this study, maize and soybean for Geocoris spp. and peanut and cotton for fire ants, but the percentage area of specific crops and woodland and pasture in the landscape and year also influenced their density in focal fields. The crop specific density of both taxa, the influence of the percentage area of specific crops and woodland in the landscape, and the variability in density over years may have been related to variable alternative resources for these omnivores in the habitats. Despite the variability over years, differential habitat use of fire ants and Georcoris spp. may have contributed to their combined ability to cause E. servus immature mortality.

Landscape Effects on Reproduction of Euschistus servus (Hemiptera: Pentatomidae), a Mobile, Polyphagous, Multivoltine Arthropod Herbivore.

Landscape factors can significantly influence arthropod populations. The economically important brown stink bug, Euschistus servus (Say) (Hemiptera: Pentatomidae), is a native mobile, polyphagous and multivoltine pest of many crops in southeastern United States and understanding the relative influence of local and landscape factors on their reproduction may facilitate population management. Finite rate of population increase (λ) was estimated in four major crop hosts-maize, peanut, cotton, and soybean-over 3 yr in 16 landscapes of southern Georgia. A geographic information system (GIS) was used to characterize the surrounding landscape structure. LASSO regression was used to identify the subset of local and landscape characteristics and predator densities that account for variation in λ. The percentage area of maize, peanut and woodland and pasture in the landscape and the connectivity of cropland had no influence on E. servus λ. The best model for explaining variation in λ included only four predictor variables: whether or not the sampled field was a soybean field, mean natural enemy density in the field, percentage area of cotton in the landscape and the percentage area of soybean in the landscape. Soybean was the single most important variable for determining E. servus λ, with much greater reproduction in soybean fields than in other crop species. Penalized regression and post-selection inference provide conservative estimates of the landscape-scale determinants of E. servus reproduction and indicate that a relatively simple set of in-field and landscape variables influences reproduction in this species.

Do trade-offs have explanatory power for the evolution of organismal interactions?

The concept of a trade-off has long played a prominent role in understanding the evolution of organismal interactions such as mutualism, parasitism, and competition. Given the complexity inherent to interactions between different evolutionary entities, ecological factors may especially limit the power of trade-off models to predict evolutionary change. Here, we use four case studies to examine the importance of ecological context for the study of trade-offs in organismal interactions: (1) resource-based mutualisms, (2) parasite transmission and virulence, (3) plant biological invasions, and (4) host range evolution in parasites and parasitoids. In the first two case studies, mechanistic trade-off models have long provided a strong theoretical framework but face the challenge of testing assumptions under ecologically realistic conditions. Work under the second two case studies often has a strong ecological grounding, but faces challenges in identifying or quantifying the underlying genetic mechanism of the trade-off. Attention is given to recent studies that have bridged the gap between evolutionary mechanism and ecological realism. Finally, we explore the distinction between ecological factors that mask the underlying evolutionary trade-offs, and factors that actually change the trade-off relationship between fitness-related traits important to organismal interactions.