Wednesday, October 28, 2009

Good Bye, My Gaogao

The Gaogao will die out on Saipan. Gaogao (Erythrina variegata var. orientalis), also known as the Cat's Claw or Coral Tree, is being attacked by the Erythrina gall wasp (Quadrastichus erythrinae) or EGW .

INFECTION AND INFESTATIONThe tiny wasps (females are 1.5mm; males are 1.0mm) lay their eggs in the young leaves and stem tissue of the Gaogao. The eggs then develop into larvae that feed upon the Gaogao as they mature.
The leaves develop damaging galls (abnormal tumors and outgrowths) and fall off. Petioles and shoots swell up and curl growing in an ineffectual manner. These pictures are of the young Gaogao trees planted across the Hyatt Hotel, Garapan on Coral Tree Road. I took these picture on October 2007. Many of the trees there are dying two years later. There is a loss of growth and vigor for the trees, and heavy infestations can cause attacks from other pests and diseases more easily. Ultimately, the trees will die. I started noticing familiar and well established Gaogao trees on my outings and hikes. Check out this leafless and lifeless giant. I found this dead tree at the Laderan Tanke Trail this year. March was supposed to be the height of this tree's blooming season. Notice the rotting bark on the trunk.The Eythrina gall wasp was first described (Kim et al. 2004) from specimens infecting trees in Singapore, Mauritius, and Reunion. The next two years saw its spread to China, India, Taiwan, Philippines, Florida, American Samoa, Hawai’i and Guam. EGW started showing up on Saipan in 2007. It is uncertain if the wasps originated from Africa according to the discoverers. Our agriculturists believe that Saipan’s pests came from Tinian and Rota. Here is a picture of the wasp's life cycle from Fleming Arboretum:

Former Glory
The Gaogao is one of my favorite native trees in the CNMI. It is also for the native fauna (birds, Marianas Fruit Bat, insects, etc.). It is a tree that can match the beauty and flamboyance of the Flame Tree as I try to convince people to plant more natives. Traditional medicine also utilizes the Gaogao.

A hike through the Laderan Tanke' Trail this past March yielded some evidence in the leaf litter that some Gaogao trees survived to flower another season.

Crafters here also bead together the purplish seeds for necklaces and Bojogo dolls that are marketed to the tourists. Here, the seeds represent the doll's hands and feet.

Erythrina trees have a variety of functions in other locations as well. The flowering of the red flowers (erythros is Latin for red) is highly associated with farming and fishing activities in Taiwan. The flowering is a working calendar by tribal peoples as sign of the arrival of spring. It is a sign for the coastal tribes to start catching flying fish, and for the Puyama tribe to plant sweet potatoes. In American Samoa, the blooming trees signal the return of whales in their waters.

The following pictures are from July 2006 at the American Memorial Park, Garapan.
These are from February 2008 in San Roque at the Park Hotel Parking lot. It was one of the better sites to watch the birds that came out to celebrate the blooming of the Gaogao.

Can you see the Egigi or Cardinal honeyeater (Myzomela cardinalis saffordi) in the picture below? This endemic subspecies of the honeyeaters found in Micronesia is a fervent nectar eater and loves the Gaogao.
There's the Egigi! The Nosa or Bridled white-eye (Zosterops conspicillatus) is usually seen as a hungry insectivore foraging on leaves and twigs. It does not shy away from the delicious nectar brought on by the Gaogao blooms though. Can you see the tiny fella in the picture below? I must have counted more than 20 birds in these trees. I am sorry for not having a camera with a nice zoom feature.
This tree is probably more than 100 ft (30.48m) tall and found in Chalan Kanoa during the 2009 bloom also in February.
These are what the seeds look like as well as the seed pod and flower bracts. These are from the trees of the CNMI Retirement Building, Capitol Hill from February of last year.

In Hawai’i, the wiliwili (Erythrina sandwicensis) another species of Gaogao is a revered native and indigenous tree. It is used as an ornamental as well as for functional landscaping (windbreaks, hedges, erosion control). The soft mature wood has been used for booms and floats for single hull canoes and long surfboards. The seeds are collected and beaded for leis that can fetch up to $500 each. Since the EGW infestation, Hawai’i has tried physical (cutting down or remove and replace), chemical and biological controls to save the wiliwili. . Some people feel that the best way to preserve the wiliwili is to collect and bank as many seeds as they can before they are all gone.

The following images of the wiliwili is from Forest and Kim Starr. The Maui based biologists work for the Univesity of Hawai'i and have an environmental consulting firm for conservation involved in protecting the wiliwili.
The beautiful wiliwili bloom.APPARENT DAMAGE
It is also unfortunate that some people in agriculture and forestry limited the planting of the Gaogao in recent years. They believed that more Gaogao trees would help host and propagate more fruit piercing moths that could eventually infect fruit crops. There is a delicate balance to nature especially in our small islands that is why we should be careful as to what is introduced in our land and waters.

We will eventually see all of the Gaogao trees die in Saipan. An article in the Marianas Variety reports that our entomologists and agriculturists will let them all die thinking that their extinction will lead to the starvation and the eventual elimination of the EGW and fruit piercing moths. In a few years, the Gaogao can be reintroduced free of pests.

This well established tree in Middle Road, San Jose across the Taste of India Restaurant withered and died this year.
I usually look forward to the Gaogao blooms in March. I enjoy watching the full crown of the trees in red and the creatures that come out for the food providing flowers. I also try to show the blooms to as many people as I can so that they are aware of the importance of CNMI’s native trees. Many of the trees that I visit for the flowers are now dead. I will miss the Gaogao sorely.
My heart breaks for you
I will miss seeing you bloom
Good bye, my Gaogao

Ti napu.

The Beachcomber


Sean said...

Wow, that is so sad. Thanks for sharing BC.

Mai said...

So sad :( is there nothing that can be done?

Deece said...

I love when the coral trees are in bloom. It's so sad to see them go.

The Beachcomber said...

Thank you for your comments, friends. It looks like the only option now is to sadly let the trees die, wait for the wasps to run out of food and die out too, and then reintroduce the trees. There are no plans by the government to chemically or biologically keep the wasps in control. There may be some Coral trees that are resistant to the wasps that may survive the pests.