By NORMAN BEZONA
By NORMAN BEZONA
University of Hawaii at Manoa College of Tropical Agriculture and Human Resources
Ebola is finally in the mainstream news. In February and March we were in West Africa when the first bits of news surfaced about the outbreak, and since that time, I have been very concerned about how this disease would spread. We left Cameroon a week before they started to clamp down on across-the-border travel in several adjoining countries. This is probably one of the worst of human diseases, and finally the international community is taking it seriously. The situation with Ebola, as with dengue fever, chikungunya and others being spread from one place to another, wakes us up to the fact that we are very vulnerable — not only with human diseases, but agricultural pests.
Several years ago, I was traveling to Nicaragua on a project supported by a grant from the United States Agency for International Development and Peace Corps through Partners of the Americas. The goal was to assist farmers there in integrated pest management and low input sustainable agriculture. One of the main objectives was to find alternatives to the pesticides that they are presently using.
Farmers in that part of the world are plagued with many more insects and diseases than we have in Hawaii. It made me realize how important it is to go through all the proper permits and inspections to insure that any seeds and plants brought to Hawaii are free of insects and diseases. Unfortunately, I came down with dengue fever and had to be shipped back home to recover. Even then, they kept me on the mainland for several weeks before I was able to return here.
This was a smart move, because Hawaii has the mosquito vector that can carry dengue from one person to another. Just a few months ago, I talked with a friend who had just returned from Bali with a full-blown case of dengue fever. If conditions had been just right, this could have caused an outbreak of dengue here. Presently, dengue is hitting islands in the Pacific and Caribbean. Initial symptoms are much like Ebola or the flu, but not as lethal in the latter stages. Most folks who get dengue or chikungunya usually recover, but like Ebola, there are no preventative vaccines.
Public health officials are going to have to really keep a close eye on travelers to avoid the spread of human diseases like these mentioned, but we must also recognize that plant and animal pests and diseases can easily be spread as well. A new pest may not affect us directly, but could destroy some of our agricultural crops, and thus hurt our farmers, ranchers, and ultimately, our economy.
Thanks to our isolation and diligent efforts of our Department of Agriculture, many potential pests have not found their way here. However, it takes the cooperation of everyone to make sure that we don’t bring in pests that could devastate our economy and overall environment.
One example is a disease that wipes out coconut palms. When I was in West Africa, I saw thousands of palms dead and dying. This disease looked much like the lethal yellowing disease that struck in Florida and the Caribbean. How did it get to Africa? From where did it come? With our planet so interconnected as it is today, it is easy to spread diseases and insects from one place to another.
Folks returning to Hawaii after a trip sometimes comment with pride about the plant or seeds they got past the inspector. Bringing unchecked plants in is foolish and dangerous. For example, the banana skipper became established here in the mid 1970s. No doubt, this insect was brought in by someone’s carelessness. The insect is a problem because it feeds on banana leaves. This requires more spraying by the farmer or homeowner. The pest also feeds on cannas, heliconias and bird of paradise. The banana bunchy top virus that threatened our Big Island banana industry is another that was probably introduced through illegal importation of banana plants.
The thought of accidently transporting pests into a non-infested area may not excite the average gardener, but beware: Plant pests tend to multiply at an amazing rate. One new female insect brought to our islands can lay hundreds to thousands of eggs. Without natural enemies, these insects could possibly ravage much of our tropical vegetation.
Another example of pest introduction is that of several species of fruit fly. These insects brought into Hawaii years ago have spread throughout the islands and caused untold millions of dollars of damage to tropical fruit and vegetables. It will cost millions to rid the islands of these pests. Just a few people illegally bringing in uninspected fruit on their travels may have caused these infestations.
And again, there is lethal yellowing. This is a disease that has claimed the lives of most Florida coconut palms as well as palms in South Texas. Luckily, we have not found one case of this disease in Hawaii. Unfortunately, it has reached Mexico and is spreading along the Caribbean Coast.
The Department of Agriculture and the University of Hawaii Plant Pathology people have checked out coconut palms that are dying for one reason or another here. Some damage may be due to herbicides applied too close to the trees. Other palms are affected by bud rot or stem bleeding disease that is often caused by physical damage such as unsanitary pruning equipment or climbing spikes. Some palms have been found to be suffering from lack of fertilizer or water. In fact, I have noticed trees dying in the Kona area where they are not irrigated. This is due to past, extended drought. All these problems are correctible, but if lethal yellowing ever gets into Hawaii, there’s no practical way of stopping destruction of our island’s palms.
When lethal yellowing hit the mainland of Florida, it was discovered that other palms are also susceptible to the disease in varying degrees. According to the University of Florida Lethal Yellowing Research Station in Fort Lauderdale, dozens of other palms are susceptible, including the Manila palm, fishtail palm, our native loulu palm and many others.
Who would want to be the cause of bringing something like this to Hawaii? You are probably thinking, “Oh, no, not me, I know if a plant is healthy or not.” Most growers do recognize the telltale signs of insect and disease activity — wilting, chewed leaves or blasted flowers. But plant pests do not always leave signs of their presence. Plants may be contaminated by microscopic cysts, larvae or insect eggs.
Anyone who wishes to transport plant materials to Hawaii, or from one island to another island, should first consult the Hawaii Department of Agriculture. These officials will brief gardening enthusiasts on any applicable regulations and aid them in complying with quarantine regulations.
Don’t be a party to the destruction of our state’s native forests, agriculture or the plants in your own yard.
For further information on gardening, you may contact the University of Hawaii College of Tropical Agriculture and Human Resources.