This pest has gained international significance in that it is a highly invasive species that has greatly expanded its geographic distribution over the last century. This insect has been found in Asia and the Pacific islands, where it causes severe losses to many commercially important tropical and subtropical crops, especially fruits. Some entomologists and quarantine biologists consider B. dorsalis to be one of the most important pest species in world agriculture. The female oviposits inside the fruit, where the larvae feed until pupation. This often causes fruit damage and fruit drop. B. dorsalis is polyphagous as well as highly invasive, so many countries impose strict quarantine restrictions to prevent its expansion to new host plants and geographic areas. These restrictions limit the world trade in agricultural commodities. In fine, because of its invasive ability, wide geographic distribution and host range, pest status, and impact on market access, B. dorsalis is considered a major threat to global agriculture. Over the past few decades, a great deal of research has been conducted on the basic ecological and biological characteristics of B. dorsalis, but the mechanisms behind molecular regulation in this species remain poorly understood. In recent years, genes related to development and stress tolerance have been studied as potential targets for effective management of this pest. The studies on the mechanism behind organophosphate insecticide resistance in B. dorsalis are an excellent example of the utility of this research strategy. Such molecular techniques can also yield insights into basic biology and ecology. Even with the current achievements on molecular regulation of B. dorsalis, a comprehensive view of this species has yet to form, largely due to the lack of genomic information. As of May 28, 2011, only 881 B. dorsalis nucleotide sequences and 615 protein sequences have been deposited in the NCBI database. These data are far from sufficient, and most of the important genes related to development and insecticide resistance are still unknown. Gene sequences are difficult to fully characterize using traditional biochemical methods, and PCR combined with RACE is a lengthy, sometimes inefficient process. The emergence of next-generation high-throughput DNA sequencing techniques has provided an opportunity for researchers to quickly and efficiently obtain massive quantities of genetic data. The Illumina technique for transcriptome analysis has been used to investigate human diseases, as well as mammals, plants, and insects. In insects, Illumina transcriptome analysis has been shown to be a reliable and precise way to study genomic characteristics, AZD6244 including development, insecticide targets, detoxifying enzymes, metabolism and immune response, and tissue specificity. This technique has not yet been applied to B. dorsalis, but we expect that a transcriptome analysis will greatly improve our understanding of B. dorsalis at the molecular level. In this study, we used short read sequencing technology for de novo transcriptome analysis. We constructed a library covering four life stages of B. dorsalis, eggs, third-instar larvae, pupae, and adults. Nearly 27 million reads of a total of 2.4 billion nucleotides were assembled into 49,804 unigenes.