Overview
I am passionate about insect ecology and species interaction. My research interests expand into aquatic insect ecology in tropical streams, Costa Rican butterfly dispersal, plant-insect interaction on leaf gall-forming in a riparian ecosystem, and the ecological specialization of plant-insect networks.
My dissertation focuses on understanding the consequences of ecological specialization and plant-insect interaction networks. My goal is to examine questions about the specialization of lepidopteran larvae (caterpillars) and provide evidence to support predictions that have been addressed about the ecological specialization (Futuyma & Moreno, 1988; Hardy et al., 2020; MacArthur, 1972). Specifically, I will document: 1) a relationship between diet specialization and abundance and whether this relationship depends on the scale of observation and measurements. 2) variation in interaction diversity of plant-arthropod communities across anthropogenic and environmental gradients. 3) microhabitat specialization of common caterpillars found on a focal host plant species. These proposed questions are designed to complete knowledge gaps on phytophagous insects' ecological specialization and surrounding environmental factors forming the ecological specialization pattern we see today. Understanding aspects of specialization, such as the relationships between the degree of resource specialization and insect abundance, will enhance our understanding of how resource specificity can determine species' distribution and complexity of ecological networks.
My dissertation focuses on understanding the consequences of ecological specialization and plant-insect interaction networks. My goal is to examine questions about the specialization of lepidopteran larvae (caterpillars) and provide evidence to support predictions that have been addressed about the ecological specialization (Futuyma & Moreno, 1988; Hardy et al., 2020; MacArthur, 1972). Specifically, I will document: 1) a relationship between diet specialization and abundance and whether this relationship depends on the scale of observation and measurements. 2) variation in interaction diversity of plant-arthropod communities across anthropogenic and environmental gradients. 3) microhabitat specialization of common caterpillars found on a focal host plant species. These proposed questions are designed to complete knowledge gaps on phytophagous insects' ecological specialization and surrounding environmental factors forming the ecological specialization pattern we see today. Understanding aspects of specialization, such as the relationships between the degree of resource specialization and insect abundance, will enhance our understanding of how resource specificity can determine species' distribution and complexity of ecological networks.
1. Diet breadth and caterpillar abundance
I am interested in investigating a relationship between dietary specialization and performance (i.e., abundance) of phytophagous insects across multiple scales of observation and indices of measuring abundance using empirical data from Ecuador. The data include diet breadth information and caterpillar (larvae of Lepidoptera) abundance sampled across space (elevational gradients) and time (17 years of data collection). It is hypothesized that caterpillar abundance will locally decrease with the increase for all observed scales as specialists would have higher fitness and reach greater local population densities than generalists (a prediction from Dyer et al., 2010).
Using Bayesian linear models and a moving window method, the results from this study provide evidence that specialists are locally more abundant than generalists, consistent with a key component of the "jack of all trades, master of none" hypothesis, which has otherwise received poor to mixed support from previous studies that have mostly involved fewer species and shorter time series. Generalists achieve greater prevalence across the landscape, and we find some evidence for geographic variation in the abundance-diet breadth relationship, in particular among elevational bands. Interspecific variation in abundance also had a negative relationship with diet breadth, with specialists having more variable abundances across species. The interesting result that more specialized species can be both rare and common highlights the ecological complexity of specialization.
Using Bayesian linear models and a moving window method, the results from this study provide evidence that specialists are locally more abundant than generalists, consistent with a key component of the "jack of all trades, master of none" hypothesis, which has otherwise received poor to mixed support from previous studies that have mostly involved fewer species and shorter time series. Generalists achieve greater prevalence across the landscape, and we find some evidence for geographic variation in the abundance-diet breadth relationship, in particular among elevational bands. Interspecific variation in abundance also had a negative relationship with diet breadth, with specialists having more variable abundances across species. The interesting result that more specialized species can be both rare and common highlights the ecological complexity of specialization.
2. Interaction diversity and environmental gradient
Ecological specialization is associated with resource availability, habitat use of a given species (Bagchi et al., 2018; Fox & Morrow, 1981), and interaction complexity. Habitats with different resource availability can host different plant-arthropod communities (Redmond et al., 2019; Robinson & Strauss, 2020; Vidal et al., 2019). In the complexity of a community and ecosystem, a research study needs to focus on a diversity of interactions (Dyer et al., 2010; Morris, 2010; Tylianakis et al., 2008) within the community as a response to a changing climate instead of traditional measures of biodiversity such as abundance and species richness. Here, I want to investigate whether there is variation in plant-arthropod communities' interaction networks across various degrees of disturbances in the Great Basin habitat. It is hypothesized that there will be variation in the network specialization and interaction diversity across anthropogenic parameters. Because the anthropogenic activities likely remove species richness and diversity, it is predicted that the interaction networks will be more sensitive to loss of relative specialist herbivores in areas with a high degree of disturbance than regions with less disturbance.
3. Microhabitat specialization
Host plant quality and caterpillar performance can potentially connect to a microhabitat experienced by the caterpillars. Here, I want to examine whether there is a local adaptation to the microhabitat. It is hypothesized that caterpillars are adapted to the local resource and microclimate created by a focal host plant species. This hypothesis will be tested in two ways: a reciprocal field experiment and a lab-based experiment. A common hypothesis is that there is a microclimate specialization among the caterpillar species found on a focal host species. It is predicted that caterpillars will perform best in their native microclimate condition (Petschenka & Agrawal, 2016). Caterpillar performance will be measured in terms of survivorship (i.e., can caterpillars survive to an adult?), developmental time, caterpillar body mass, and pupal mass (Dyer et al., 2013; Lill & Marquis, 2001).