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Hawai'i

I think this is the characteristic fiddlehead of hapu'u i'i (Cibotium menziesii)
In the summer of 2011 I had a rare opportunity to present my research at two conferences in the Hawaiian islands.  Because of my interest in tropical agriculture and plant pathology I arranged to spend the month between the two conferences as a visiting scholar at the USDA-ARS Pacific Basin Agriculture Research Center in Hilo.  I gained insights into a variety of interesting research projects being conducted by the USDA, Forest Service, and University of Hawai'i (some of which are detailed below). 
You can read a synopsis on the Department of Plant Pathology's website.

Having spent 2001 working on coffee farms in Hawai'i I looked forward to returning and learning about other crops in the diverse Hawaiian agricultural markets and the unique problems they face.  While previously exploring the island I also developed a deep appreciation for the endemic flora of Hawai'i.  Through contacts at the University of Hawai'i and US Forest Service I was able see some of the emerging invasive pests that are further threatening native species.

2011 meeting of the American Phytopathological Society (APS)
The 2011 APS meeting included many exciting talks and workshops. There were a slew of participants from New Zealand, Australia, and the Pacific Islands that offered unique perspectives on their own challenges in plant pathology. 
*more to be added soon

XIII International Symposium on Biological Control of Weeds  (ISBCW)

It was terrific to present at the ISBCW meeting with a group of the world's top researchers in the field of weed biocontrol.  I gained insights into the practical challenges associated with implementing weed biocontrol programs as well as the latest research news.


Visiting researcher at Pacific Basin Agriculture Research Center, USDA-ARS
The USDA-ARS research station in Hilo is tasked with investigating pest control and crop genetics for tropical agriculture.  They also develop quarantine strategies and technologies to prevent the post-harvest movement of tropical pests with quarantine requirements.

I tried to help with as many USDA research opportunities as possible while staying in Hilo.  Fruit fly management was one of the original projects implemented at PBARC and one of the great success stories of pest management.  A big component of fruit fly control lies in understanding behavior. I helped with a few field trials investigating lure and trapping efficacy.  I was interested to see some innovative techniques using machine vision and RFID chips to track individual flies and determine their mating behavior.  These techniques have implications for revealing pathogen dispersal behavior in my own research.  There are many emerging niche markets in Hawai'i that are growing to fill the void left by the collapse of the sugar industry on the islands.  Dr. Francis Zee has helped to introduce a number of novel crops to the island and encouraged local adoption by growers.  Locally grown tea has been met with some excitement and I was able to see some research plots where varieties of tea are being tested for suitability in the unique Hawaiian growing conditions.  I did some sampling for disease in these trial varieties and isolated pathogenic organisms from brown and grey leaf blights.  There were a number of talks at the APS annual meeting about Puccinia psidii, "guava rust," a fungal pathogen with a wide host range in the Myrtaceae.  Newly introduced to the islands, Puccinia psidii has already been observed attacking many tree species in Hawai'i and poses a threat to the ecologically crucial, endemic Ohi'a tree.  I surveyed a few sites for incidence of Puccinia psidii on a variety of different hosts.

fruit fly larva emerging from (Solanum psuedocapsicum)
grey blight on tea (Camellia sinensis)
Brush cherry (Eugenia paniculatum) leaf with uredinia from Puccinia psidii

Fruit fly maggot emerging from Jerusalem cherry; grey blight on tea leaf; Puccinia psidii on Brush Cherry (Click on pictures to see more)

Weed biological control has been attempted for a number of invasive plants in Hawai'i.  Thanks to Mike Robinson from the Department of Hawaiian Homelands, I was able to see a massive infestation of the invasive weed Gorse and a number of management tactics, including biocontrol releases, that were being used to suppress it.


Gorse infested rangelands treated with herbicides; Sugi planted as a barrier to shade out encroaching gorse; Spider mite biocontrol (Click on pictures to see more)

Koa is an amazing tree in its unique botanical features as well as its wood properties.  Old growth Koa stands still serve the majority of the Koa wood supply though the availability of these trees is now dwindling. Dr. James B Friday from University of Hawai'i extension is hoping that younger trees planted in restoration efforts and silvaculture will offer suitable quality wood to sustainably meet the demands for Koa.  I was able to help survey small stands of Koa trees and spotted some Koa rust, Atelocauda digitata!


Koa rust uredinia
Koa rust spores; Koa phyllodes (modified stems, not true leaves); witches broom symptoms (Click on pictures to see more)



The trail is right over there...
One of my favorite native Hawaiian ecosystems is the tree fern rainforests composed of endemic understory species.  These unique forests
look ancient and are filled with the sounds of native songbirds.  I was able to accompany Michael Long, a researcher at UH Manoa, in the field to collect samples from leaf litter traps. Michael is looking at the differences in forests with and without pig-exclusion fencing.  Feral ungulates have a massive impact on native Hawaiian flora.  They uproot tree ferns and spread seeds of invasive plants. The differences between the two treatments were immediately noticeable from my brief observations.  The pig-exclusion sections were incredibly dense and lush and seemed to host a wider variety of understory plants.  It was there that I saw the critically endangered 'Aku'aku (Cyanea platyphylla), a spiny endemic Hawaiian plant.  It was a terrific opportunity to see sections of forest that get as close to pristine as you can find in Hawai'i.  Even in sections of forest with fencing in place for only several years, the differences were striking.



Young red frond of 'Ama'u (Sadleria spp.)

The distinctive red frond of the 'Ama'u fern; One of many tiny Agaricales; black fungal fruiting bodies on a downed tree limb (click on pictures to see more)

Pheromone and protein bait traps are an integral part of area-wide fruit fly control.  Depending on the types of lures and trap designs fruit fly traps can be used to simply monitor or suppress pest populations.  I assisted with several field collections that were a part of testing the efficacy and specificity of different traps/lures over time. 




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