If pesticides are bombs intended for pests, then butterflies, bees and other species are often collateral damage.
A new material developed by Kansas State University (K-State) researchers may both eliminate off-target killings and deliver much more effective management of important stored-grain pests, disease-causing insects and other threats. A multidisciplinary team led by John Tomich, professor of biochemistry and molecular biophysics, developed a nontoxic material that can deliver biomolecules that are lethal to a particular species. The material is made of peptides—combinations of amino acids—formed into tiny capsules that are harmless to the environment.
“The best way to think of it is that we have developed a carrier, and we stick active ingredients to it,” Tomich said. “We could target termites, roaches, or vectors like mosquitoes, and we can go specifically for that species as opposed to using something that kills other species.”
Species-specific weapons also fight pesticide resistance, a growing problem worldwide.
Tomich and his colleagues took aim at Tribolium castaneum, known as the red flour beetle, and Acyrthosiphon pisum, known as the pea aphid. The red flour beetle infests stored products, particularly food grains, and the pea aphid inflicts damage on forage crops such as alfalfa and clover. In addition to their status as worldwide pests, these public enemies are model species for studying insect development, according to researchers. The tiny capsules Tomich and his team developed will make studying these species and other insects easier.
“Many insects are so small that you can’t inject anything into them—tiny thrips and similarly-sized insects,” Tomich said. “This approach delivers the active ingredients orally, allowing them to be studied more effectively.”
Yoonseong Park, professor of entomology at K-State, investigated how the active ingredients traveled through the cells of the insects. As an entomologist, he is most interested in the development of potential pesticides and he plans to further investigate whether the biomolecules prefer specific types of cells or organs in different species. In this study, he found that the ingested nucleic acid moved through many different types of cells.
Park said the study demonstrated promising results.
“This technology will enable future medical and therapeutic tools. It carries infinite possibilities,” Park said.
The study, “Delivery of lethal dsRNAs in insect diets by branched amphiphilic peptide capsules,” was published Feb. 2 in the Journal of Controlled Release.
Other K-State coauthors were Raman Chandrasekar, research associate in biochemistry and molecular biophysics; Kayla E. Wilkinson, James Balthazor, Matthew Heerman and Jarrod Bechard, present and former graduate students in biochemistry and molecular biophysics; Susan Brown, university distinguished professor of biology; and Gerald Reeck, professor of biochemistry and molecular biophysics. Additional coauthors included Adriana Avila-Flores from Auburn University. Avila-Flores completed her doctorate at Kansas State University and worked in Tomich’s lab and then for Reeck before obtaining a tenured position at Auburn.
Partial support for the project was provided by the university’s Johnson Cancer Research Center and by the USDA’s National Institute of Food and Agriculture through the Specialty Crops Research Initiative/Citrus Disease Research and Extension. — K-State
