Delivery of intrahemocoelic peptides for insect pest management

• Transcytosis across the gut epithelium can be exploited for insect pest control.
• Luteovirus coat proteins deliver neurotoxins from the insect gut into the hemocoel.
• Plant lectins also deliver intrahemocoelic toxins from the insect gut.
• Entomopathogenic fungi deliver intrahemocoelic toxins via the insect cuticle.

The extensive use of chemical insecticides for insect pest management has resulted in insecticide resistance now being recorded in >500 species of insects and mites. Although gut-active toxins such as those derived from Bacillus thuringiensis (Bt) have been successfully used for insect pest management, a diverse range of insect-specific insecticidal peptides remains an untapped resource for pest management efforts. These toxins act within the insect hemocoel (body cavity) and hence require a delivery system to access their target site. Here, we summarize recent developments for appropriate delivery of such intrahemocoelic insect toxins, via fusion to a second protein such as a plant lectin or a luteovirus coat protein for transcytosis across the gut epithelium, or via entomopathogenic fungi.