Adipokinetic hormones (AKH) [1,2] are small active peptides produced by some insect species. They bring on the release of diglycerides from the fat body and then stimulate the flight muscles to use them as an energy source. Other types of active peptides structurally related to AKH are:

• Hypertrehalosaemic factors (HTF), which are neuropeptides that elevate the level of trehalose in the hemolymph of some insects.
• Red pigment concentrating hormone (RPCH), a peptide that stimulates pigment concentration in prawn and crab erythrophores.

These peptides are eight to ten amino acid residues long. The signature pattern to detect them is based on the sequence of the first eight residues, which are common to all these peptides.