he rapid warming of the Earth caused by anthropogenic factors has profound long-term implications for preventing pests and controlling vector-borne diseases. Put simply, Arthropods, ectotherms animals, do better in a warmer world. One of the advantages of a more hospitable environment is spreading geographically to establish new niches. However, appropriate communication both within and between individuals is crucial for successful niche realization, and one of the most ancient ways of communication occurs via chemicals and chemoreception. This project will examine chemosensory adaptations to specialized lifestyles in two arthropods as biological models. First, Ixodes ricinus (Chelicerata) is a vector for multiple tick-borne diseases common in Europe and, as a result, has a significant impact on public health. Despite their epidemiological importance, there is still limited knowledge of the chemosensory system of this species, and thus a poor understanding of host-seeking behavior and chemical ecology. By a comprehensive phylogenetic analysis and comparative genomics approaches, we will investigate how the chemosensory receptor genes are conserved or diversified in seven tick species from five of the major genera in the family of hard ticks (Ixodidae), I. ricinus, I. persulcatus, Haemaphysalis longicornis, Dermacentor silvarum, Hyalomma asiaticum, Rhipicephalus sanguineus and R. microplus. In addition, we will sequence and analyze the transcriptomes of the mouthparts of the tick I. ricinus to identify candidate gustatory and olfactory receptor genes and compare their expression levels in male and female ticks. The highly abundant chemosensory receptor genes will then be cloned and functionally characterized in the Xenopus oocyte heterologous expression system. On the other hand, we will annotate the chemosensory gene families in the ambrosia beetle Trypodendron lineatum, second biological model. We previously sequenced and assembled this species genome. Here, we aim to utilize the large amount of genomic data that resulted from a separate comparative genomics study to identify chemosensory genes. In addition, we planning a transcriptomic sequencing for a proper genome annotation. The T. lineatum genome will be globally annotated using automated annotation pipelines, and analysis of gene family expansions will be conducted for comparisons with available bark beetle genomes (Ips typographus and Dendroctonus Ponderosae) to seek for genomic signatures of the specialized lifestyle of ambrosia beetles as fungal farmers and eusocial insects.