Thursday | September 03, 2015
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Avoid importing diseases when traveling

Updated: 
August 10, 2014 - 12:13am

Ebola is finally in the mainstream news. In February and March I was in West Africa when the first bits of news surfaced about the outbreak and since that time, I have been concerned about how this disease would spread.

I left Cameroon a week before they started to clamp down on across-the-border travel in several adjoining countries. This is one of the worst 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 both to human diseases and agricultural pests.

A few months ago, I talked with a friend who had just returned from Bali with dengue fever. If conditions had been just right, this could have caused an outbreak 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 must keep a close eye on travelers to avoid the spread of human diseases like these mentioned, but we must recognize that plant and animal pests and diseases can easily be spread as well. A new pest could destroy some of our agricultural crops and 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 we don’t bring in pests that could devastate our economy and 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 similar to the lethal yellowing that struck Florida and the Caribbean. How did it get to Africa? From where did it come? With our planet so interconnected 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 is foolish and dangerous.

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 plants. The banana bunchy top virus that threatened our Big Island banana industry also was probably introduced through illegal importation of banana plants.

Plant pests 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 ravage much of our tropical vegetation.

And again, there is lethal yellowing. This disease has claimed the lives of most Florida coconut palms as well as palms in southern Texas. We have not yet found a case of this disease in Hawaii, but 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 caused by 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 suffer from lack of fertilizer or water. I have noticed trees dying in West Hawaii where they are not irrigated because of past, extended drought. All these problems are correctable, but if lethal yellowing ever gets into Hawaii, there’s no practical way of stopping destruction of our island’s palms.

Most growers 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 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 more gardening information, contact the University of Hawaii College of Tropical Agriculture and Human Resources.