The complete genomes of 19 of the world’s most damaging pest insects have been mapped – paving the way for more targeted pesticides and other control measures.
The work includes such notorious threats to crops as the melon/cotton aphid (Aphis gossypii), cotton whitefly (Bemisia tabaci) and beet armyworm (Spodoptera exigua).
To date, the number of high-quality public domain pest genomes has been limited. Publication of the new data should not only provide the basis for learning more about the biology and behaviour of the insects, but allow new light to be shed on the mode of action of pesticides used against them, the international team of researchers wrote in Pesticide Biochemistry and Physiology.
Resistance genes highlighted
For 15 of the species, information about the genes involved in resistance to toxins has also been published, which could open the door to new methods of control with reduced impacts on non-target species.
“There is a need to develop new insecticides with improved pest selectivity that overcome pre-existing resistance mechanisms and to develop novel and more benign forms of pest control,” the scientists said.
“All these goals can be supported by the availability of pest insect genomes, which play an increasingly important role in crop protection research.”
New solutions to old problems
Advances brought about as a result of the genomic information could include new target proteins for pesticides, resulting in more selective chemistry, new pesticide modes of action, better understanding of the role played by host crops in bringing about resistance, as well as gene editing to block such resistance.
New chemical pathways tailored to overcome the metabolism of pests but not beneficial insects may avoid the kind of issues seen with the use of neonicotinoids, which have been widely banned due to their effects on bees.
The work could also lead to the development of non-pesticide methods of control, such as techniques to disrupt the species’ mating and cause populations to fall below levels of economic threat.
The full list of pest insects sequenced:
Agriotes lineatus (click beetle/wireworm), Aphis gossypii (melon/cotton aphid), Bemisia tabaci (cotton whitefly), Brassicogethes aeneus (pollen beetle), Ceutorhynchus obstrictus (seedpod weevil), Chilo suppressalis (striped rice stem borer), Chrysodeixis includens (soybean looper), Diabrotica balteata (cucumber beetle), Diatraea saccharalis (sugar cane borer), Nezara viridula (green stink bug), Nilaparvata lugens (brown plant hopper), Phaedon cochleariae (mustard beetle), Phyllotreta striolata (striped flea beetle), Psylliodes chrysocephala (cabbage stem flea beetle), Spodoptera exigua (beet army worm), Spodoptera littoralis (cotton leaf worm), Diabrotica virgifera (western corn root worm), Euschistus heros (brown stink bug), Phyllotreta cruciferae (crucifer flea beetle).
