Understanding the landscapes and the elements that make up the landscapes can help us understand the entire natural ecosystems and biodiversity. Landscape ecology has been studied since the past. however, many studies are conducted on single landscapes, and comparative studies between landscapes are few. We compared insect species diversity and community structure within a single plant community across landscapes and habitat. Additionally, identify environmental factors that affect diversity. Our results showed that above-ground and below-ground insect communities were clearly distinguished. Additionally, species diversity was high below-ground in all landscapes. Insect community structures across landscapes did not differ in above-ground. However, below-ground, the urban was differentiated from the forest and agricultural land. We identified the urbanization indices GMIS and PHBASE as factors responsible for these difference.

Individual plants can provide space for various herbivore communities, and multiple herbivores often colonize different parts of the same plant. Plants can therefore play an important role in shaping community composition in ecosystems by mediating interactions among herbivore. Plant-mediated interactions among different folivores or between above-and below-ground herbivores are relatively well understood. However, although important for structural support and nutritional transport, the stem is largely unknown in how it responds to stem-feeding herbivores, or whether leaf- and stem-responses to herbivore attack are integrated. Interestingly, I found that JA signaling is also important for resistance to the stem herbivore, and, interestingly, that N. attenuata induced lignin and chlorogenic acid in stems in the face of stem herbivore attack. I also further found that plant inducible defenses in the pith and in the leaf are not systemically induced other tissues, but systemic induction of JA signaling was asymmetric between the stem and the leaf. I conclude that tissue-localized defense responses allow tissue-specialized herbivores to share the same host and occupy different chemical defense niches in the same hostplant.

Herbivorous insects use plant metabolites to inform their host plant selection for oviposition. These host-selection behaviors are often consistent with the preference-performance hypothesis; females oviposit on hosts that maximize the performance of their offspring. However, the metabolites used for these oviposition choices and those responsible for differences in offspring performance remain unknown for ecologically-relevant interactions. In this time, I will talk about the host-selection behaviors of two sympatric weevils, the Datura (Trichobaris compacta) and tobacco (T. mucorea) weevils in field- and glasshouse-experiments with transgenic host plants specifically altered indifferent components of their secondary metabolism. In addition, I will show that adult females are able to choose the best host plant for their offspring and use chemicals different from those that influence larval performance to inform their oviposition decisions.