Hawaii's Invasive Species

They aren’t cute, cuddly or shy. Here are six new—or just pesky—invasive species you should know about.


Published:


Photo: Courtesy HDOA

 

1. Small hive beetle, roughly one-third the size of a honey bee and native to sub-Saharan Africa. Discovered: Big Island, 2010. Feeds on wax and honey in hives, destroys comb and causes fermentation of  honey. What’s being done: mechanical traps and pesticides; biocontrol (introducing a predator) is being researched.

 


Photo: Courtesy HDOA

 

2. Naio thrips, a 2-mm-long insect, either from New Zealand or Australia (unknown). Discovered: Big Island, 2009. The thrips has had a severe effect on the ornamental landscape plant naio; it feeds on its leaves, causing them to form heavy galls. The concern is that it will move into native naio forests. What’s being done: chemical control.

 

 


Photo: Courtesy HDOA

 

3. Varroa mite, a pinhead-size, red, crablike mite, native to Southeast Asia. Discovered: Oahu, 2007, and Big Island, 2008. Kills wild and managed bee populations by sucking the blood from honey bees and their young. What’s being done: chemical control, traps, cultural controls and biocontrol is in research.

 

 


Photo by: M. Tremblay

 

4. Erythrina gall wasp, a gnat-size, brown insect with wings, native to East Africa. Discovered: Oahu, 2005, and has spread statewide. Feeds on non-native and native erythrina trees (including wiliwili), causing the leaves and stems to form galls, which halt normal plant functions. What’s being done: a natural enemy wasp was released in 2008.

 

 


Photo: Courtesy CTAHR


5. Ohia rust, a microscopic fungus, likely from Florida. Discovered: Oahu, 2005, and has spread statewide. This particular strain of rust affects plants in the myrtaceae family (of which ohia is one) and has caused huge die-offs of the rose apple. The concern is that another strain will arrive and affect native ohia. What’s being done: No known treatments or control measures available.

 

 


Photo: Courtesy HDOA


6. Nettle caterpillar, a sluglike caterpillar with spines, originally from Southeast Asia. Discovered: Big Island, 2001; Oahu and Maui, 2002. Has stinging spines that cause pain and symptoms similar to man-of-war. Found on plants—grass, ti, palms—common in yards. What’s being done: chemicals and biocontrol; a tiny wasp that feeds on nettle caterpillars was released in 2010.

 

 

Sources: Christy Martin, public information officer for Hawaii’s Coordinating Group on Alien Pest Species, and Neil Reimer, chief of the Plant Pest Control Branch for the Hawaii Department of Agriculture.

 

 

Subscribe to Honolulu