We monitored colonization and population dynamics of the tarnished plant bug (TPB) Lygus lineolaris in replicated 2 m by 2 m plots of different weed species as well as adjacent crop and noncrop habitats over two field seasons in upstate New York. Given the broad diet of TPB our null expectation was that patterns would be similar across habitats. Contrary to this expectation, however, we observed marked differences in relative abundance among habitats through the season. Plant phenology, particularly onset of flowering, appeared to play a key role in determining colonization and abundance patterns. Although TPB has a very large host range, it feeds on young, rapidly developing tissue, such as flower buds or young fruit. In this sense, it is a host tissue specialist. Availability of such tissue varies both in time and space. Our current research efforts are focusing on the extent to which host plant volatiles and visual cues are used by TPB to find these ephemeral resources.