Abstract: Provided are chimeric Hemiptera-active insecticidal toxin proteins comprising a Bt toxin peptide with activity against Hemiptera, a peptide multimer or fusion protein containing such peptide which binds to the gut of sap-sucking insects, preferably the Asian citrus psyllid, Diaphorina citri. This insect carries a bacterium associated with Huanlongbing disease or citrus greening and damages citrus crops. When bound, this peptide mediates the binding of the chimeric insecticidal protein to the target insect gut. Also described are coding sequences, vectors, and transgenic plants genetically modified to contain and express such insecticidal proteins. Other delivery mechanisms such as use of phloem-inhabiting bacteria, are also contemplated. Thus, the use of these toxins reduces economic loss due to feeding by the target insect and also reduces loss due to plant diseases spread by the target insect.