Trehalose is not only an important disaccharide, but also a key stress resistance factor in the development of many organisms, including plants, bacteria, fungi, and insects. To study the potential function of trehalose in development and behaviour, cDNA for a trehalose-6-phosphate synthase from Catantops pinguis (CpiTPS) was cloned and sequenced. Results revealed that the CpiTPS cDNA sequence contains an open reading frame of 2430 nucleotides encoding a protein of 809 amino acids with a predicted molecular weight of 91.13 kDa and a pI value of 6.25. Northern blot and RT-PCR analyses showed that CpiTPS mRNA expression was high in the fat body and testes, ovaries, Malpighian tubules, brain, trachea, rectum, and posterior extensor of C. pinguis. Northern blotting revealed that CpiTPS mRNA was expressed in the fat body at different developmental stages and was present at a high level in first instar larvae and adults. The results demonstrate that CpiTPS is a key gene in C. pinguis development.