Be on alert for this bug

January 24, 2006

ANNAPOLIS - An unusual insect has been designated Maryland's "Invader of the Month" - not because it's been seen here yet, but because it hasn't.

The Sirex noctilio, a wood boring wasp new to the United States was identified last February by Dr. Richard Hoebeke after it was collected in a September 2004 forest survey trap sample from Fulton, N.Y.

The wasp is known to be a serious pest in South America, Australia, New Zealand and South Africa, attacking and infecting pine forests, the Maryland Department of Agriculture said last week.

Officials of the department's Forest Pest Management Section are asking area residents to be on the lookout for the insect. "Early detection and intervention is the key to success," MDA said in a news release.


"Although there are several other horntails in our area, any suspicious insect should be caught, kept and sent to an entomologist for identification," MDA said. "If you find any insect of concern, contact Dick Bean, entomologist, at MDA at 1-410-841-5920.

MDA said an ongoing survey in New York has so far turned up 85 adults and larvae from within a 40-mile radius from the initial find.

The wasp "should be able to thrive anywhere in North America where there are pine forests. ...Like many other wood boring insects, S. noctilio tends to favor stressed trees, but it also attacks and kills apparently healthy trees as its populations grow. It has been known to kill up to 80 percent of the trees in stands of North American pine species grown in plantations in South America.

"The main reason it is such a threat is because as the female horntail inserts its eggs in trees, it also inoculates the wood with a fungus," MDA said. As the fungus grows, it serves as food for the wasp larvae and "can also rapidly kill the trees," MDA said.

"Once she emerges, the large female wasp is a strong flyer - as far as 100 miles - and infestations in other countries expand 5 to 15 miles per year."

The New York discovery has federal and state officials concerned and planning to survey more intensively in other nearby states, MDA said.

Scientists are looking for parasites and predators to combat this serious threat. A parasitic nematode being used in Australia has shown promise. Also, efforts are underway to develop better lures and trapping methods to detect its presence earlier in new infestations.

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