Aaron Iverson

• PhD
• Professor (Assistant) at St. Lawrence University

Land-use and local field management affect pollinators, pest damage and ultimately crop yields. Agroecology is implemented as a sustainable alternative to conventional agricultural practices, but little is known about its potential for pollination and pest management. Sub-Saharan Africa is underrepresented in studies investigating the relative impo...

In the tropics, smallholder farming characterizes some of the world's most biodiverse landscapes. Agroecology as a pathway to sustainable agriculture has been proposed and implemented in sub‐Saharan Africa, but the effects of agricultural practices in smallholder agriculture on biodiversity and ecosystem services are understudied. Similarly, the co...

In response to anthropogenic environmental change, the cues that animals use throughout their lifecycle to optimize fitness may become unreliable, resulting in an ecological trap. Here we investigated whether commercial bumble bee Bombus impatiens colonies managed for early spring crop pollination act as ecological traps for wild nest‐searching Bom...

Remote Amazonian communities are often largely self-sufficient, made possible in part by their agricultural skills and deep ecological knowledge of their landscapes. Mastery of their local flora undoubtedly plays a vital role in daily life, yet communities in the Amazon can vary widely in both the diversity of plants that they utilize and in how th...

Naturally occurring predator and parasitoid communities are well known to respond to multiple scales of environmental heterogeneity within and around agroecoystems, yet our understanding of which scales are most influential on different functional guilds of enemies is limited. Using vote-counting methodology, we synthesized the results from 40 empi...

Several beetle species in the family Coccinellidae have evolved close associations with ants in order to consume ant-tended hemipteran prey. These myrmecophilous lady beetles employ various strategies for avoiding ant aggression, including physical and chemical protection. We asked how the lady beetle Diomus lupusapudoves Vandenberg, Iverson and Li...

Whether an ecological community is controlled from above or below remains a popular framework that continues generating interesting research questions and takes on especially important meaning in agroecosystems. We describe the regulation from above of three coffee herbivores, a leaf herbivore (the green coffee scale, Coccus viridis), a seed predat...

Pollinators such as bumble bees are in decline as a result of many factors, including loss of habitat. Initiatives to improve and restore pollinator habitat are increasingly popular. However, to most effectively conserve pollinators, we need a better understanding of which habitats limit their survival and fitness at the landscape scale. Our study...

Resistance and resilience have become important concepts in the evaluation of disturbance events, providing a framework that is useful in light of the expected increase in frequency and occurrences of hurricanes as a consequence of climate change. Hurricane Maria landed on Puerto Rico as a category 4 storm in September of 2017. Among the affected e...

Human land use threatens global biodiversity and compromises multiple ecosystem functions critical to food production. Whether crop yield–related ecosystem services can be maintained by a few dominant species or rely on high richness remains unclear. Using a global database from 89 studies (with 1475 locations), we partition the relative importance...

Human land use threatens global biodiversity and compromises multiple ecosystem functions critical to food production. Whether crop yield–related ecosystem services can be maintained by a few dominant species or rely on high richness remains unclear. Using a global database from 89 studies (with 1475 locations), we partition the relative importance...

Understanding how different pesticides influence bee health is inhibited by a limited knowledge about the interactions between different compounds to which bees are simultaneously exposed. Although research has demonstrated synergistic effects of some sterol biosynthesis inhibiting (SBI) fungicides on the toxicity of certain insecticides to bees, a...

Human land use threatens global biodiversity and compromises multiple ecosystem functions critical to food production. Whether crop yield-related ecosystem services can be maintained by few abundant species or rely on high richness remains unclear. Using a global database from 89 crop systems, we partition the relative importance of abundance and s...

Significance Decades of research have fostered the now-prevalent assumption that noncrop habitat facilitates better pest suppression by providing shelter and food resources to the predators and parasitoids of crop pests. Based on our analysis of the largest pest-control database of its kind, noncrop habitat surrounding farm fields does affect multi...

A new species of myrmecophilous lady beetle, Diomus lupusapudoves, sp. nov. (Coleoptera: Coccinellidae: Diomini), is described from a coffee agroecosystem in Chiapas, Mexico. The new species was found preying on the green coffee scale pest, Coccus viridis (Green), tended primarily by Azteca sericeasur Longino and Pheidole synanthropica Longino ants...

Natural enemy diversity may be beneficial, through species complementarity, or detrimental, through antagonistic interactions, such as competition or intraguild predation, for the biological control of agricultural pests. We studied two coexisting myrmecophilous coccinellid beetles, Azya orbigera (Mulsant) (Coleoptera: Coccinellidae) and an undescr...

The intensification of agriculture drives many ecological and environmental consequences including impacts on crop pest populations and communities. These changes are manifested at multiple scales including small-scale management practices and changes to the composition of land-use types in the surrounding landscape. In this study, we sought to exa...

Increased agricultural intensification has led to a decrease in biodiversity and the deterioration of important agricultural ecosystem services, such as biological control. Parasitoid wasps are important biological control agents for many crop pests, and augmenting their abundance and diversity may confer significant economic and environmental bene...

Biodiversity loss—one of the most prominent forms of modern environmental change—has been heavily driven by terrestrial habitat loss and, in particular, the spread and intensification of agriculture. Expanding agricultural land-use has led to the search for strong conservation strategies, with some suggesting that biodiversity conservation in agric...

Agriculture comprises the largest global land use, makes it a leading cause of habitat loss. It is therefore critical to identify how to best construct agricultural systems that can simultaneously provide food and other ecosystem services. This challenge requires that we determine how to maximize win‐win relationships and minimize trade‐offs betwee...

Background/Question/Methods Agricultural intensification is implicated as a major driver of global biodiversity loss. Local management and landscape scale factors both influence biodiversity in agricultural systems, but there are relatively few studies to date looking at how local and landscape scales influence biodiversity in tropical agroecosyst...

Background/Question/Methods Over the past several decades agricultural lands have become increasingly intensified. This has consequently lead to a deterioration in biodiversity, increased habitat homogeneity, and the degradation of important ecosystem services such as biological control. In many agroecosystems, such as coffee farms, parasitoid wa...

Background/Question/Methods Agricultural land-use is a strong driver of biodiversity loss considering that around 40% of the terrestrial land surface is now covered by agriculture. Yet, some agricultural systems can maintain high levels of biodiversity, for example shade coffee plantations can maintain high species diversity. At the same time, ma...

Background/Question/Methods The simplification of communities is thought to have important consequences for ecosystem functioning. In agriculture, these consequences may have immediate ramifications for species interactions that are valuable to humanity, including pest control and pollination. However, understanding if interactions between foodwe...

Background/Question/Methods Agricultural lands currently cover ~40% of the earth’s terrestrial surface, and increased agricultural intensification has resulted in the degradation of biodiversity and various ecosystem services associated with agriculture. However, individual agroecosystems have varying impacts on ecosystem services, and attention...

Agroecological factors at local-management and landscape scales influence organisms residing in agriculture. Management for control of insect pests of agricultural commodities can be facilitated by our knowledge of these factors. We sampled for a minor coffee pest, a leaf-chewing beetle (Rhabdopterus jansoni), across sites that varied in coffee sha...

This study focuses on the distribution and abundance of one species of Chrysomelid beetle, Rhabdopterus jansoni, within Mexican coffee plantations and aims to observe how different techniques of coffee management affect the abundance of this coffee herbivore.

Agricultural intensification is implicated as a major driver of global biodiversity loss. Local management and landscape scale factors both influence biodiversity in agricultural systems, but there are relatively few studies to date looking at how local and landscape scales influence biodiversity in tropical agroecosystems. Understanding what drive...

Agricultural intensification is implicated as a major driver of global biodiversity loss. Local management and landscape scale factors both influence biodiversity in agricultural systems, but there are relatively few studies to date looking at how local and landscape scales influence biodiversity in tropical agroecosystems. Understanding what drive...

Background/Question/Methods Agricultural intensification over the past several decades has resulted in serious environmental impacts, including habitat simplification and a correlated loss of biodiversity, leading to compromised ecosystem services such as biological control of pests. Structurally and biologically diverse agroecosystems have been...

Background/Question/Methods Biotic factors affect species distribution and abundance therefore the overall impact of organisms on ecosystems. Indeed, some species have a strong effect on the distribution of other species because they act as keystone species that cascade (up or down) their effects to other trophic levels. In addition to their impor...

Background/Question/Methods Land-use change is considered the strongest driver of biodiversity loss. An alarming fact considering that approximately 40% of the terrestrial land surface is now used for agriculture. Yet some agriculture practices maintain high levels of biodiversity, and therefore it is essential to understand which components are...

Background/Question/Methods Diverse agroecosystems are important providers of ecosystem services. Although many studies have investigated the individual ecosystem services provided by these systems, there is a need to quantify whether tradeoffs or synergies exist between individual ecosystem services. We considered several ecosystem services, inc...

Background/Question/Methods Biotic and abiotic contexts can alter the outcome of defense mutualisms between plants and their partners. This conditionality may be specifically true for indirect ant-plant mutualisms mediated by honeydew-producing hemiptera (hereafter hemiptera) because plants may compete for ant attendance with other plants that al...

We tested the role of salicylic acid (SA) and jasmonic acid (JA) in altering the tomato plant's defense against herbivory by tobacco hornworm. Treatments of SA or JA were topically applied to tomato plants, hornworm consumption was allowed to proceed for 12 days, and harvest analyses were performed. Measurements taken included a subjective plant ra...

We tested chemical and insect feeding-induced insect resistance on soybean plants. The chemical induction effects of jasmonic acid (JA) and salicylic acid (SA) were investigated. We also evaluated the effects of plants stressed with previous insect herbivory. A larval antibiosis screening technique (LAST) and a preference test were performed in pet...

White-tailed deer (Odocoileus virginianus) have been increasing dramatically in the eastern United States, with concomitant increases in impacts resulting from deer browsing and deer-vehicle collisions. In Ohio, the number of deer were estimated at near zero in 1940 to over 450,000 in 1995. We analyzed estimates of deer harvest and deer-vehicle col...