Neuropeptides are diffusible signal molecules mediating vital physiological processes in metazoans. A group of peptides in insect homeostasis includes the diuretic hormones. The osmoregulatory neuroendocrine system has been suggested as a possible target for the development of new biopesticides. We tested in vivo function of a corticotropin releasing factor like-DH₄₇ (TcDH₄₇) in the red flour beetle Tribolium castaneum (Herbst), which belongs to the group of desiccation tolerant coleopteran species.  The genome sequence of the T. castaneum has recently been completed.  We identified the gene encoding TcDH₄₇ which has identical deduced amino acid sequence to the Tenmo-DH₄₇ previously described in Tenebrio molitor (Linnaeus), except that the C-terminus of TcDH47 is amidated, while Tenmo-DH47 has a free acid form of carboxy terminus_. We studied the in vivo activity of Tenmo-DH₄₇ in adult T. castaneum using a highly sensitive humidity chamber assay. The chamber assay consisted of a humidity analyzer measuring the change in humidity from the air passing through a chamber containing a single insect in which we injected either Tenmo-DH₄₇, 8 bromo-cAMP or Ringer’s solution (treatment, positive, and negative controls, respectively). Excretions from the individual beetle in the chamber were instantly evaporated and detected by the humidity sensor.  Injection of Tenmo-DH₄₇ into adult T. castaneum induced significant levels of diuresis. A sexually dimorphic response was detected where the female has a higher sensitivity to the Tenmo-DH₄₇ by excreting approximately 200 nL compared to about 60 nL in the male.