Preferably, the cadherin is a Bacillus thuringiensis (B.t) insecticidal crystal protein (Cry) toxin receptor.

Disclosed are fusion polypeptides comprising a Cry protein, or crystal-forming domain thereof, and an antimicrobial protein.

Also in some preferred embodiments, the fragment is administered with a Cry protein that is active against a dipteran.

Some of the approved products contain a single Cry protein, but increasingly ‘pyramids’ expressing two Cry proteins are grown.

In some preferred embodiments, the protease-stable BtB is used in combination with B.t. spores and/or crystals comprising a Cry protein.

When used in this manner, the peptide fragment can not only enhance the apparent toxin activity of the Cry protein against the insect species that was the source of the receptor but also against other insect species.