If you spot one of them, you should report it right away to the Pest Hotline at 808-643-PEST. You can also report a pest online and find all the information you need at Hawaii's new one-stop shop website at dlnr.hawaii.gov/hisc.
Invasive species are a big problem in Hawaii due to the state's geographic isolation. Hawaii's native plant and animal species (those that arrived here naturally via wind, waves and birds) have little defense against competitive species.
The results can be really destructive to Hawaii's natural ecosystem. Miconia, an invasive plant from South America, for example, overtakes forests and prevents the growth of other plants, causing erosion. The Brown Tree Snake decimated bird populations on Guam. If you've been on the Big Island at dusk, you've probably heard the chorus of Coqui frogs, which chirrup annoyingly from dusk to dawn, but also disrupt the balance of vulnerable native ecosystems.
While the Brown Tree Snake is not known to be present in Hawaii at this time, eight were discovered in the state between 1981 and 1998, mostly likely carried here in civilian and military vehicles or cargo from Guam.
The Wood Rose, with its yellow flowers, can be seen in many Hawaii yards, but the woody, climbing vine is considered invasive and chokes and smothers plants.
Click here to see a quick list of invasives in Hawaii.