Native nanasu plant under attack by bark beetleWritten by Clynt Ridgell
Guam - Another native plant of Guam is under attack from another beetle. Although this attack is in its early stages experts warn that the nanasu is in danger.
The nanasu is a native bush or shrub that makes a nice green ornamental hedge. In fact, it currently lines the sidewalks and roadsides of Guam’s tourist district in Tumon. “Couple of weeks ago it was noticed that some of these plants are starting to die," said UOG Entomologist Dr. Aubrey Moore.
These dying plants were first noticed by GVB contract inspector Ilene Quitugua. "The wilting the leaves turning yellow and then the following week the plants are dying the leaves are falling off it’s turning brown,” said Quitugua.
Dr. Moore then took some samples of the dying Nanasu back to his lab and now he’s about 90 percent sure he's found the culprit. "Well we think it’s a bark beetle which is a little tiny beetle,” said Dr. Moore. It’s hardly visible it’s only like a little millimeter in size,” said Dr. Moore. In fact, the beetle is smaller than the letter "A" on a dime.
To be 100 percent sure that this is the culprit Dr. Moore needs to know the exact species of this bark beetle. "We don't know what species this bark beetle is. I had to send specimens as far away as Florida to a specialist who will be able to identify it hopefully to species and the reason this is important is if we know the species name it unlocks all of the knowledge globally on that species so we'll know what plant its attacking and how to control it,” said Dr. Moore.
Dr. Moore and Department of Agriculture Entomologist Dr. Russ Campbell both agree that eradication is out of the question and our only recourse now is to control it. However, this too could prove to be troublesome because this particular plant likes to grow near the coastline on beaches which means that any pesticide or poison that is used to kill this bart beetle must also be safe for marine life.
Whatever control method is found it needs to be found fast. "From the time we notice they are affected it’s within two weeks and the plant is dead already,” said Denson Fairfield of LMS adding, “On the San Vitores road for the nanasu plants that we currently maintain I would say about 75-80 percent of the plants are affected right now but that are already dead about 30-40 percent."
The nanasu is a native plant of Guam, a good ornamental hedge and it has medicinal properties. For example, there are bulbs that grow on it that when squeezed provide a juice that can be used as natural eye drops. The eye drops were traditionally used by Chamoru fisherman prior to the introduction of masks. The eye drops from the nanasu were used to soothe the irritation caused by salt water.