Methods for identifying arthropod repellents based on modulation of specific ionotropic receptors, and compounds and compositions identified by such methods

A method of identifying a compound that is a repellent for at least one arthropod species, comprising:

• a) contacting an Ir40a receptor or Ir40a receptor-expressing neuron with a candidate compound;
• b) measuring the activity of the Ir40a receptor;
• c) comparing the activity of the Ir40a receptor after contact with the candidate compound to the activity of the Ir40a receptor in the absence of the candidate compound;
• and
• d) identifying a compound that is a repellent for at least one arthropod species by determining whether or not the candidate compound modulates the activity of the Ir40a receptor.

A method of identifying a compound that is a repellent for at least one arthropod species, comprising:

• a) providing a sample comprising a full-length or partial Ir40a receptor protein from Drosophila melanogaster or an ortholog thereof;
• b) contacting the sample with a candidate compound;
• c) measuring the activity of an Ir40a receptor in the sample;
• d) comparing the activity of the Ir40a receptor after contact with the candidate compound to the activity of the Ir40a receptor in the absence of the candidate compound;
• and
• e) identifying a compound that is a repellent for at least one arthropod species by determining whether or not the candidate compound modulates the activity of the Ir40a receptor.