Maintaining the delicate balance between insect control and resistance has long been a challenge for growers of all commodities.

Rotation has been the call from the scientific community because too much of a good thing can be really bad if you only have a few weapons in your arsenal and pests build resistance.

Understanding how the Asian citrus psyllid (ACP) develops resistance to crop protection products is the topic of CRDF-funded research by Dr. Lukasz Stelinski, a University of Florida entomologist based at UF’s Citrus Research and Education Center in Lake Alfred.

Early results fromyear one of this two-year project funded in 2010 show that five CYP4 genes may be promising candidates for RNA-interference to silence over-expression of genes associated with insecticide resistance in ACP.

These newly identified genes may also serve as DNA-based screening markers for cytochrome P450-mediated insecticide resistance in field populations of ACP.

Stelinkski explains how his research could make a difference in the industry’s fight against citrus greening disease, and its vector the Asian citrus psyllid (ACP).

“Understanding the genetics behind how resistance to insecticides develops in populations of Asian citrus psyllid will aid in the development of sound resistance management programs,” said Stelinski.

“Our recent identification of new genes in ACP, whose expression appears to be tied up to imidacloprid resistance, is a first step in this direction. Imidacloprid is currently one of our most important tools for ACP management, particularly for protection of young trees.

“These new data may have useful practical application in addition to helping us understand the genetics behind imidacloprid resistance.”

Stelinski added, “As we continue using imidacloprid and other insecticides for management of ACP, it will be important for us to continue monitoring for insecticide resistance annually to understand how populations of these insects are responding to our control tools in the field.

“Knowing which specific genes to investigate gives us an additional, and very sensitive DNA-based screening tools for imidacloprid resistance.”

Stelinski’s research on this topic will soon be published in Insect Molecular Biology, a peer-reviewed journal published by Wiley-Blackwell. To view Stelinski’s entire CRDF report or to view other CRDF-funded projects visit