Tropical Gardening: Dangerous disease, pests pose potential hazards in the garden

  • 2470219_web1_IMG_3901.jpg

Spring fever and an urge to get out and putter in the garden are common almost anytime of the year in Hawaii.


Spring fever and an urge to get out and putter in the garden are common almost anytime of the year in Hawaii.

This year, we need to be aware dengue fever also might be something to consider.

More than 30 confirmed cases have been reported to date on the Big Island. That means when folks are out sharing nature with mosquitoes, it is important to be protected with repellent and clothing to avoid being bitten. Screened windows, doors and perhaps even mosquito netting over beds might be wise in warm, wet areas where mosquitoes thrive.

We have had dengue outbreaks before and this one might be minor as well, but it takes diligence to clean up areas where mosquitoes breed. Check for standing water in garden pools, containers, water catchment tanks and water-holding plants such as bromeliads. Flushing out bromeliads weekly with fresh water or treating with a biological mosquito control such as Bacillus thuringiensis subspecies israelensis will kill mosquito larvae. This mosquito specific biocontrol is available under several brand names at local garden shops.

Dengue is just one of many mosquito transmitted diseases with which we should be concerned. There has been a serious epidemic of chikungunya in the South Pacific. West Nile virus is another that can be transmitted to humans from infected birds.

We are all getting better educated about the potential hazards of bringing plants and animals into Hawaii without following the proper procedures. Agricultural inspections and quarantines are a way of life when we travel these days, but now we are reminded again serious human diseases also lurk in the shadows only to be inadvertently introduced into the Islands.

Of course, it is common sense flu and similar illnesses can come with travelers. We experience this each flu season, but dengue fever, yellow fever and perhaps even malaria could become a problem if we are not careful.

Unfortunately, we have the specific mosquito carriers, or vectors, present. They also require a reservoir where the disease organisms can reside unnoticed.

Some research shows dengue can be harbored by animals other than humans, such as monkeys, pigs or rats; although, this seems to be rare. I learned this several years ago through a conversation with a state Department of Health worker. The reason I was concerned was because I became very sick with dengue on a Peace Corps trip to Nicaragua. I was so sick I had to delay coming home for two weeks.

If I had felt better, I would immediately have returned to Hawaii, thus inadvertently being potentially infectious. If the right mosquito found me and then bit someone else, they could have become infected.

Dengue also is called Breakbone Fever because an infected person feels like every bone in the body was damaged. This condition can last for weeks.

It is important to be aware of the potential of this disease and others, since quite a few Hawaii residents are returning from Southeast Asia, South Pacific and South America this year, where dengue is epidemic.

Travelers should be aware if they are running a fever upon returning to the Islands, it would be a good idea to check in with their local physician or Urgent Care Clinic.

Thanks to our isolation and diligent efforts of our state departments of agriculture and health, many potential pests or diseases have not found there way here. However, it takes the cooperation of everyone to make sure we don’t bring in pests that could devastate our economy and overall environment.

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.

For example, the banana skipper became established here in the mid-1970’s. No doubt, this insect was brought in by someone’s carelessness.

It 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 the Big Island banana industry is another disease probably introduced through illegal importation of banana plants.

The thought of accidently transporting pests into a noninfested area might not excite the average gardener, but beware. Plant pests tend to multiply at an amazing rate.

One new female insect brought to the Islands can lay hundreds to thousands of eggs. Without natural enemies, these insects possibly could 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 spread throughout the Islands and caused untold millions of dollars in damage to tropical fruit and vegetables.

And again, there is lethal yellowing. This is a disease that killed most of Florida’s coconut palms. Luckily, we have not found one case of this disease in Hawaii. Unfortunately, it reached Mexico and is spreading along the Caribbean Coast.

If lethal yellowing ever gets into Hawaii, there is no practical way of stopping the destruction of our Islands’ palms. According to the University of Florida Lethal Yellowing Research Station in Fort Lauderdale, dozens of other palms are susceptible, such as the Manila palm, fishtail palm, our native loulu palms and many others.

Who would want to be the cause of bringing some pestilence 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 activity — wilting, chewed leaves or blasted flowers. But plant pests do not always leave signs of their presence.

Plants might be contaminated by bacteria, virus, larvae or insect eggs even if we don’t see them.

With the world being open to travel, we must be even more cautious about spreading unwanted pests and diseases.


Hawaii County Civil Defense is hosting a series of community meetings around the Big Island about dengue fever. All meetings are at 6 p.m. The remaining meetings are:


• Monday (Nov. 16), Hilo High School cafeteria.

• Tuesday (Nov. 17), Keaau High School cafeteria.

Leave a Reply

Your email address will not be published. Required fields are marked *


By participating in online discussions you acknowledge that you have agreed to the Star-Advertiser's TERMS OF SERVICE. An insightful discussion of ideas and viewpoints is encouraged, but comments must be civil and in good taste, with no personal attacks. If your comments are inappropriate, you may be banned from posting. To report comments that you believe do not follow our guidelines, email