The Asian citrus psyllid can carry citrus greening, which is one of the most devastating citrus diseases in the world.
The department said it was important to stop the spread of this now in California before it seriously damages citrus production there.
The funds will be used for intensive surveillance for Asian citrus psyllid and citrus greening disease. It will also support quarantine regulations, as well as outreach and education about the pest to California's nursery owners, the citrus industry and the public.
USDA's Animal and Plant Health Inspection Service confirmed California's first detection of Asian citrus psyllid in San Diego County on September 2.
It is also working with Imperial County, Texas and Louisiana due to the presence of the pest there, and with officials in Mexico.