Categorized | Agriculture, Health

Opinion: An open letter to the Dept of Health on biocontrol

Institute for the Study of Culturogenic Disease
P.O. Box 1880, Pahoa, Hawaii 96778
(808) 935-5563

May 19, 2009

Chiyome Fukino, M.D.
Director, Hawaii Department of Health
1250 Punchbowl St.
Honolulu, Hawaii 96813

Re: Potential human health impacts from exposure to biocontrol scale insect infestations

Aloha Dr. Fukino:

I am a medical anthropologist and director of the Institute for the Study of Culturogenic Disease, located on the Big Island.

As you know, Hawaii leads the nation in childhood asthma and respiratory disease. We are very concerned this may get worse from exposure to insects that will be infesting our island as part of a biocontrol experiment, and ask your attention to this matter.

The US Forest Service Pacific Southwest Research Station’s is planning to release a scale insect from Brazil, Tectococcus ovatus, as a biological control for strawberry guava. We believe this insect poses potential threats to the health of residents and visitors which have not been adequately addressed by the Forest Service.

To our knowledge, research has never been done on the potential allergenicity or other health impacts of human exposure to Tectococcus ovatus – its eggs, waxy filament, chitinous material, crawling nymphs, winged males, and females. Chitin is known to cause pulmonary inflammation and is highly allergenic. Inhalation of these tiny insects and their eggs and nymphs may induce severe allergic response.

Given the high rates of asthma in Hawaii and the negative impact of volcanic emissions on pulmonary health, this exposure to T. ovatus may be even more problematic.

This Brazilian scale insect has never before been used for biocontrol, nor has it been introduced into any alien environment, so this release is unprecedented and completely experimental. Little was known about this insect prior to research into its use as a biocontrol agent for strawberry guava, and it is relatively rare in Brazil.

Expected population densities in Hawaii could be very large, since there are no natural predators of this insect in Hawaii to limit its numbers, and there will be hundreds of thousands of acres of infested strawberry guava trees.

Since its primary mode of travel is with the wind, this proposed experimental infestation could create dangerous quantities and densities of airborne Tectococcus ovatus eggs, nymphs, and flying males to which people will be exposed.

Many residents live near strawberry guava and will contact and inhale these eggs, nymphs, and flying males. The nymphs and males, like tiny mites, will crawl over the skin and get into eyes, ears, mouths, noses, hair and clothes. Fruit will also have galls containing adult females, as well as having nymphs crawling on them and eggs adhering to them, all of which will be unintentionally eaten.

However, legitimate concerns over potential health impacts from this insect infestation have been brushed aside as insignificant by the Forest Service, without the benefit of evidence or necessary research.

The following quoted statements are the extent that this issue has been addressed, from the “Petition for field release of Tectococcus ovatus (Homoptera: Eriococcidae) for classical biological control of strawberry guava, Psidium cattleianum Sabine (Myrtaceae), in Hawaii”, May 10, 2005, by Tracy Johnson of the Institute of Pacific Islands Forestry, US Forest Service Pacific Southwest Research Station.

“Human Impacts
“Direct contact between humans and T. ovatus is likely to (be) minimal because the insects are enclosed within leaf galls most of their lives.”

This statement is misleading, since it does not consider the direct contact with eggs and nymphs, or with flying males.

“Humans near infested P. cattleianum (strawberry guava) may experience chance contact with the eggs, crawlers and waxy filaments which emerge from female galls, but are unlikely to be aware of them because of their small size.”

This statement is not based on any scientific evidence. Many people are aware of small arthropods crawling on their skin, in their eyes, and into their ears, such as mites, tiny ants, and other small crawling insects. People living or hiking near dense areas of strawberry guava may be exposed to thousands of eggs and nymphs at one time.

“Allergenicity of substances generated by homopterous insects is rare. It appears very unlikely that T. ovatus poses any risk to human health.”

As far as we know, there has never been a study of the potential allergenicity of Tectococcus ovatus – its tiny eggs, waxy filament, chitinous material, crawling nymphs, winged males, and females. Given the expected density of scale infestation and numbers of insects and insect parts that will be airborne, if this scale does prove allergenic, it could be devastating to human health.

“Simultaneous emergence and dispersal of large numbers of male T. ovatus could possibly cause occasional nuisance to humans if the winged males are attracted to lights. However, males are tiny (2 mm long) and appear to be weak fliers.”

If these flying males are attracted to light, they could become a major nuisance, and increase human exposure to and contact with these insects. This statement also shows how little is known about this insect.

We believe the following questions should be answered before this biocontrol experiment is allowed:

  1. How will inhaling airborne T. ovatus eggs, crawling nymphs and flying males affect asthmatics?
  2. What other health problems might be caused, both acutely and chronically, by exposure to this insect, its eggs, nymphs, and chitin?
  3. I am extremely concerned about potential allergic sensitization. Is the scale insect or any of its parts or in any of its stages of life an allergen?
  4. How many eggs, nymphs, and male insects floating and blowing in the wind will people be exposed to, especially in heavily infested strawberry guava areas?
  5. Will people be annoyed by these insect eggs, crawling nymphs, and flying males?
  6. Eggs, crawling nymphs, and scales will be on the strawberry guava fruit of infested trees. What will be the health impacts of ingesting these?
  7. Will there be eye, ear, nose, or throat irritation as a result of exposure?
  8. Will people itch and scratch themselves in response to contact, creating rashes and potentially harmful skin infections?
  9. To what degree is consumption of strawberry guava fruit beneficial for public health, given its high fiber, vitamin, mineral, and anti-oxidant content, and its current widespread availability, and to what degree might this consumption fall as a result of this infestation, adversely affecting public health?

On behalf of thousands of residents concerned about this infestation of our environment and its potential health impacts, we would appreciate your attention to this issue and a prompt response to the above questions.

Thank you.

Sydney Ross Singer
Medical Anthropologist
Director, Institute for the Study of Culturogenic Disease
P.O. Box 1880, Pahoa, Hawaii 96778
(808) 935-5563

2 Responses to “Opinion: An open letter to the Dept of Health on biocontrol”

  1. Benjamin says:

    Mr. Singer’s theories of all kinds are not accepted scientific explanations. Just read his web page:

    Or take a look at the wikipedia entry for his book:

    “The book’s claim that bras cause breast cancer has been dismissed by the medical and scientific communities; the National Cancer Institute,[1] the American Cancer Society,[2] and the National Institutes of Health[3] have all concluded that there is no link between bra use and breast cancer.”

    Mr. Singer does not have standing, unless you believe in conspiracy theories, paranormal, or way alternative health practices (like crystal healing) – he knows some fancy footwork in writing/speaking but the core information is hocus pocus.

    The health affect of another insect in Hawaii….seems to be none unless it stings or bites. The allergy/asthma angle is pretty weak, these aren’t cockroaches (a real asthma connection) that will be moving into your house. Many many types of insects live in trees in Hawaii, build webs and end up on hikers, gardeners and farmers.

    Stawberry Guava is a real problem for protecting native spieces, maintaining a pasture, garden or a nice looking yard. Look at some of the areas in Puna for examples of this plant gone wild – it’s a weedy tree with a bad habit of taking over.

    I would add one question to Mr. Singer’s list: Why is this inflated ego wacko getting so much coverage on the blogs?

  2. James says:

    Instead of attacking Sydney Singer, we should be looking at the questions he raises. Will this insect cause problems? Where’s the research to answer the above questions?


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