Mia K Lippey

Bio: Mia K Lippey is an academic researcher from University of California, Davis. The author has contributed to research in topics: Medicine & Agriculture. The author has an hindex of 1, co-authored 1 publications receiving 2 citations.

The complexity of global change and its effects on insects.

Abstract: Global change includes multiple overlapping and interacting drivers: 1) climate change, 2) land use change, 3) novel chemicals, and 4) the increased global transport of organisms. Recent studies have documented the complex and counterintuitive effects of these drivers on the behavior, life histories, distributions, and abundances of insects. This complexity arises from the indeterminacy of indirect, non-additive and combined effects. While there is wide consensus that global change is reorganizing communities, the available data are limited. As the pace of anthropogenic changes outstrips our ability to document its impacts, ongoing change may lead to increasingly unpredictable outcomes. This complexity and uncertainty argue for renewed efforts to address the fundamental drivers of global change.

Increasing crop field size does not consistently exacerbate insect pest problems

Abstract: Significance Economies of scale in agricultural production continue to promote shifts to larger monocultural plantings of crop plants. Contrary to widely accepted views on resource concentration in monocultures, we find that larger field sizes do not consistently amplify the severity of arthropod pest impacts. Although smaller fields may enhance biodiversity and augment many ecosystem services, including pollination, our analysis shows that simply downsizing the scale of agriculture will not consistently ameliorate pest impacts. Additional work on pest and natural enemy overwintering and movement biology is needed to understand why larger field sizes can amplify, reduce, or have no effect on pest severity across different pest-crop systems.

Reply to Marini et al.: Insect spill-over is a double-edged sword in agriculture

Abstract: Agroecologists have long suggested that increasing the size of agricultural fields, one of the main features of agricultural industrialization, worsens problems with insect pests (1, 2). Recent research has examined the effects of mean field size across landscapes, suggesting highly context-dependent outcomes (3, 4). But, despite elegant theory describing insect responses to the size of a particular focal crop field (5, 6), there is a surprising deficit of empirical research addressing the question: should farmers plant smaller fields to improve pest control? Our study addressed this knowledge deficit. We found that smaller fields are sometimes associated with ameliorated pest impacts (the conventional expectation), but more often are associated with unchanged or worsened pest impacts (7). As Marini et al. (8) note, our work examined the size of a single focal field and not the mean size of fields in the surrounding landscape. Generating knowledge about focal field size is important, as individual farmers can adjust the size of their fields, but often cannot implement changes across landscapes. Nevertheless, we agree that landscape context is important and that additional research is needed to explore landscape-scale mean field size, as well as many other factors that could modulate focal field size effects. We further concur with Marini et al. (8) that fine-grained landscapes may result in “improved landscape complementation and the facilitation of spill-over of organisms between crop and non-crop patches.” This does not necessarily imply improved pest control, however. Enhanced resource complementation and spill-over of organisms are double-edged swords: they may augment not only predators but also pests. We respectfully disagree with Marini et al. (8) that our results failed to consider landscape-level factors sufficiently. Our statistical models controlled for landscape context by i) including key landscape-level covariates (natural habitat remnants; amount of the focal crop); ii) fitting spatial smoothers that corrected for regional differences in pest abundance; and iii) including fixed effects for ranch identity. Controlling for ranch identity isolates the effect of focal field size while holding constant features of the broader surrounding landscape. Furthermore, if any landscape effects leaked through our attempts at statistical control, we would expect them to make our conclusions more conservative. Smaller fields are most often found in landscapes with other small fields; thus, if small-field landscapes enhance pest control, it should only have made it more likely that we would observe lower pest densities in smaller focal fields. We did not observe that. The sampling design proposed by Marini et al. (8) has clear efficiencies for parsing potential interactions of local and landscape field size. Maximizing efficiency is important when researchers must gather data with their own hands. However, the ecoinformatics methods that we used capitalize on farmer-generated data, decentralizing the labor-intensive task of data collection and yielding larger (ca 100×) data sets that are likely to include a broad array of landscape contexts (9). Such datasets could readily be analyzed to examine interactions of localand landscape-scale factors. We agree with Marini et al. (8) that such work is worth pursuing.

Testing the potential benefits of small fields for biocontrol needs a landscape perspective

Abstract: Rosenheim et al. (1) present an interesting study testing the effect of focal field size on pest suppression across multiple cropping systems. The main conclusion of their study is “The idea that larger field sizes consistently disrupt natural pest control services is without foundation in either the theoret - ical or empirical record.” We argue that this general conclu - sion should be considered with more caution. First, Rosenheim et al. focused on the local effect of field size com - paring pest density in small vs. large fields irrespective of the configuration of the surrounding landscape. However, most of the empirical research providing evidence for a positive effect of reducing field size on pest suppression or natu - ral-enemy enhancement has tested the effect of landscape configuration (e.g., gradients in field size or edge density in the surrounding), usually adopting specific designs to control for differences in landscape composition (2–5). Decreasing field size at the landscape scale is expected to have more pervasive effects than the size of the focal field alone. Fine-grained landscapes usually have a higher density of margins and higher microhabitat diversity, resulting in improved land - scape complementation and in the facilitation of spill-over of organisms between crop and noncrop patches (6). This scale dependence was not fully acknowledged in the study, generating confusion between the reported lack of a local effect and the potential—but not investigated—effect of reducing mean field size at larger spatial scales. Second, the data used (1) come from unplanned field obser - vations by farm staff, consultants, and pest control advisors who quantified pest pressures without any sampling design. As pest suppression is often context dependent, many poten - tial biotic and abiotic drivers of success or failure exist (7, 8). Without a robust design, observational landscape studies usu

Growth and development of an invasive forest insect under current and future projected temperature regimes

Abstract: Abstract Temperature and its impact on fitness are fundamental for understanding range shifts and population dynamics under climate change. Geographic climate heterogeneity, behavioral and physiological plasticity, and thermal adaptation to local climates make predicting the responses of species to climate change complex. Using larvae from seven geographically distinct wild populations in the eastern United States of the non‐native forest pest Lymantria dispar dispar (L.), we conducted a simulated reciprocal transplant experiment in environmental chambers using six custom temperature regimes representing contemporary conditions near the southern and northern extremes of the US invasion front and projections under two climate change scenarios for the year 2050. Larval growth and development rates increased with climate warming compared with current thermal regimes and tended to be greater for individuals originally sourced from southern rather than northern populations. Although increases in growth and development rates with warming varied somewhat by region of the source population, there was not strong evidence of local adaptation, southern populations tended to outperform those from northern populations in all thermal regimes. Our study demonstrates the utility of simulating thermal regimes under climate change in environmental chambers and emphasizes how the impacts from future increases in temperature can vary based on geographic differences in climate‐related performance among populations.

Assessing Climate Change Impacts on Island Bees: The Aegean Archipelago

Abstract: Simple Summary In this study, we conducted, for the first time, an extensive climate change impact assessment of bee pollinators in the Aegean Islands, Greece, a regional bee hotspot in the Mediterranean. We located the current biodiversity and future extinction hotspots in the region and identified areas in urgent need for conservation prioritization, by undertaking an overlap analysis with the established protected areas network in Greece. Most bee species occurring in the archipelago are expected to face severe range contractions and there is evidence of an underlying extinction debt in the study area. Our work could serve as the baseline for the integration of a rather neglected, yet extremely economically and ecologically important taxonomic group, the bees, in the systematic conservation planning in the archipelago. Abstract Pollinators’ climate change impact assessments focus mainly on mainland regions. Thus, we are unaware how island species might fare in a rapidly changing world. This is even more pressing in the Mediterranean Basin, a global biodiversity hotspot. In Greece, a regional pollinator hotspot, climate change research is in its infancy and the insect Wallacean shortfall still remains unaddressed. In a species distribution modelling framework, we used the most comprehensive occurrence database for bees in Greece to locate the bee species richness hotspots in the Aegean, and investigated whether these might shift in the future due to climate change and assessed the Natura 2000 protected areas network effectiveness. Range contractions are anticipated for most taxa, becoming more prominent over time. Species richness hotspots are currently located in the NE Aegean and in highly disturbed sites. They will shift both altitudinally and latitudinally in the future. A small proportion of these hotspots are currently included in the Natura 2000 protected areas network and this proportion is projected to decrease in the coming decades. There is likely an extinction debt present in the Aegean bee communities that could result to pollination network collapse. There is a substantial conservation gap in Greece regarding bees and a critical re-assessment of the established Greek protected areas network is needed, focusing on areas identified as bee diversity hotspots over time.