This SURVEY OF MOSQUITO CONTROL PRACTICES—AND LESS-TOXIC ALTERNATIVES is a report prepared for the Maryland Coastal Bays Program (MCBP) which is a non-profit partnership formed to restore and protect Maryland’s coastal bays.

The Md. coastal bays support many species of fish, crabs, shellfish and other life in the aquatic food chain, birds and waterfowl, turtles, frogs, etc. The region’s waterways include, in addition to the bays, a number of streams, creeks, salt and fresh water marshes, wetlands and tidal estuaries. These are a part of the environmentally sensitive habitats sought to be protected by the MCBP comprehensive plan.

A number of government agencies are supporting the program including: the Town of Ocean City, Worcester County, the State of Maryland, and the National Park Service, US Environmental Protection Agency, etc. Citizen advocates, natural resources experts, boating, fishing, golfing and other interests are actively participating in the program, and working to help achieve the MCBP objective—to restore and protect Maryland’s coastal bays environment.

Quotes/Excerpts—MCBP Comprehensive Plan

The Maryland Coastal Bays Program (MCBP) comprehensive plan has recognized that:

“pesticides . . . can have devastating environmental, as well as economic impacts” and that

“alternative techniques to control pests . . . minimize damage to the environment”

(Comprehensive Plan, Pg. 46, 6/99)

This report is one of the many steps and actions within the MCBP’s Comprehensive Plan.

Contents of this Report—Summarized

Non-toxic alternative actions which the public can take to assist in mosquito control are shown in Chapter II. These are the self-help activities which can be used in residential back yards, and around businesses. The topics include: Removal of standing water, use of “Mosquito Dunks”, Purple Martin bird houses, Bat houses, Larvae-eating fish for ornamental ponds, and Repellents. Although natural resources personnel are likely aware of these matters, many people in the general public need to become better informed, in order to have broader cooperation. Government mosquito control agencies are also involved in these activities, publicizing information, encouraging public participation, and helping the public to help themselves. However, the publicity

has often omitted mentioning all of the environmentally friendly methods, and thus there are gaps in the awareness which need to be filled by broader coverage.

The principal governmental activities for mosquito control through their adulticide and larvacide spraying activities are shown in Chapter III. References are presented of states, towns and communities using the various least-toxic and less-toxic methods. Briefly, larvaciding is the least toxic alternative, and adulticiding the most toxic, within the spraying portion of the programs. Therefore, programs which maximize larvaciding and eliminate (or minimize) adulticiding are more “friendly” to the environment. Larvaciding-Only is the least-toxic method, followed by Adulticiding Only-Hot-Spots, and by No Aerial Adulticiding. Worcester County has recently adopted the policy of No Aerial Adulticiding, except in case of a disease emergency, confirmed by the State’s Health Dept.

Combinations of various methods to assist in mosquito control are known as IPM, (Integrated Pest Management) and most programs include such kinds of IPM methods. Examples of environmentally friendly methods discussed in Chapter III include: Thoroughness of larvaciding, Open Marsh Water Management, Answering complaints, Assisting backyard clean-ups, Legal requirements for clean-ups, etc. Also, in Chapter II, the government programs are discussed for: Gambusia-mosquito fish, the old tires problem, publicity for clean-ups, etc.

The more technical aspects of product toxicities are presented in Chapter IV. The adverse effects of adulticiding are discussed, including: Measures of toxicity, Fish-kills and Harming other species, and Hazards to People.

Adulticides do not specifically target the mosquitoes, but are killing and injuring a wide variety of wildlife species. Also, adulticides can be hazardous to people. Tables are shown, ranking the toxicities of mosquito control products. There is also discussion of the West Nile situation in NY, and the way in which toxicity has been mitigated, even in their emergency situation. Briefly, NY has changed to adulticide products which have evidenced less adverse effects. Malathion has been phased out, and Resmethrin and Sumithrin products substituted in NY’s emergency situation.

Md’s selection of adulticides is also discussed in Chapter IV . The product Naled, (rated in the highest toxicity class), is the adulticide used by Md for aerial spraying. The citizens preparing this report are urging Md. to discontinue use of Naled, and to adopt the lower toxicity products Resmethrin and Sumithrin.

Miscellaneous topics are presented in the Appendices. The control program for gypsy moths is covered in Appendix-D. Mosquito control is done over substantially greater acreages than spraying for gypsy moths, thus reducing the concern for impacts from the gypsy moth program.

Groups Advocating Less-Toxic Alternatives

The Maryland Coastal Bays Program (MCBP) is one organization among many which are advocating the adoption of less toxic mosquito control alternatives. During this survey a number of other organizations were found to be actively promoting the same kinds of objectives. The following is a partial list of organizations, and references:

Illinois, McHenry County Defenders, -- Improving Mosquito Management, Least Toxic Solutions

(1/7/97) (1)

Maryland Pesticide Network, supported legislation, Task Force to Study Mosquito-Borne Public Health

Hazards (SB 710) (Feb., 2000) (2)

New York Environmental Advocates, NY Public Interest Research Group—Toward Safer Mosquito

Control in New York (Jan, 2000) (3)

Northwest Coalition for Alternatives to Pesticides—Managing Mosquitoes Without Poisons (12/93)

(4)

North Carolina, Agricultural Resources Center, Pesticide Education Project, PESTed NEWS, Aerial

Spraying Breeds Dangers (5)

Information Sources and References

In compiling information for this report, we used information, mostly from electronic sources (the web) and some from newspapers and periodicals. A significant number of states are reporting their practices on the web and in newspapers, and are included in this report. Where states have not publicized their practices, no comments could be included. Telephone interviews were also done, speaking with supervisors in Maryland and in the neighboring states of Virginia, Delaware and New Jersey to supplement published sources.

References to websites, newspapers, and periodicals are shown within each section of the report.

References:

(1) http://www.mcdef.org/mos.htm

(2) http://mlis.state.md.us/2000rs/billfile/sb0709.htm

(3) http://www.nypirg.org/mosquito.html

(4) Journal of Pesticide Reform, 12/93

(5) http://metalab.unc.edu/arc/newsletters.htm

SURVEY OF MOSQUITO CONTROL PRACTICES—AND LESS-TOXIC ALTERNATIVES

II. Non-toxic/ Natural Controls—Needing Public Participation

In this Chapter II we report on the mosquito control practices which members of the public can perform by their own efforts. These are the self-help steps that residents and small businesses can use around their yards and grounds, their gardens, boats and piers, etc. Promotions and publicity are important components to help increase public awareness and participation in these non-toxic alternatives. The following sections discuss the topics: Standing Water Removal , the use of “Mosquito Dunks”, Purple Martin birds, Bats, Larvae-eating fish, and the use of Repellents.

II.1 STANDING WATER REMOVAL

All states and all mosquito control districts, towns and cities support the removal of standing water, as an essential component of mosquito control.

It is uniformly stated and restated that STANDING WATER REMOVAL is one of the essential steps. Sometimes this is called source reduction, backyard cleanup, etc., but the purpose is always the same, i.e. to get the public to cooperate in doing the cleanups to eliminate water which has accumulated for more than four days.

There is rarely an article on mosquito control that omits mentioning standing water removal as one of the important, basic steps in preventing mosquitoes in your neighborhood. Also, there are numerous reports devoted entirely to this subject, for example:” HOW TO AVOID BREEDING MOSQUITOES AROUND YOUR HOME,” or “ARE YOU BREEDING MOSQUITOES IN YOUR YARD?

Standing Water Breeds Mosquitoes:

Mosquitoes can only breed in water, and thus removal of their standing water breeding source is very important. Mosquito authorities are continually emphasizing the importance of doing backyard cleanups of standing water. One example of the kind of statement giving an incentive to participate in cleanups is the following excerpt/quote. (Gainsville Mosquito Control)

“Recent rains have helped spawn new generations of mosquitoes hatched in containers such as pots, buckets, tires, bird baths, rain gutters, etc. When they emerge to adulthood, mosquitoes generally range no farther than 50 yards from the container they lived in as larvae. Usually the neighborhood blood supply is plentiful enough to keep the females—the biters among mosquitoes -- happy.” (1)

Maryland Supports Standing Water Removal

A Md. brochure was recently mailed (July, 2000) to residents of one community in Worcester County promoting the removal of any standing water in their yards, to assist in mosquito control efforts. The brochure included a list of common water sources to be checked and emptied in yards. This was the first year that such direct mailing occurred, promoting the removal of standing water by Md’s mosquito control agency.

In August 2000, the Asian Tiger mosquito became a nuisance in the Baltimore area according to recent Sunpapers articles. This species (Aedes albopictus) breeds only in containers and therefore the principal method of control is to remove standing water sources and conduct a publicity campaign. Recently the Baltimore Sunpaper (2) has published several articles on the front page, and in the local section which discussed the problem and gave detailed recommendations for removal of standing water, as presented by Md’s mosquito officials.

Several other mosquito species which also breed in containers (Culex, Aedes, etc.) will also be controlled when standing water is removed. The Culex pipiens is thought to be the main species spreading West Nile Virus in NY, thus emphasizing the importance of removing standing water.

If there are areas where standing water cannot be drained, “Mosquito Dunks” can be used, as discussed in section II.2.

Md’s Mosquito Control Website (Excerpts/Quotes)

“If a Marylander is bothered by tiger mosquitoes, it is likely that the mosquitoes were produced in his/her yard or the property adjacent to it. The most effective method of controlling these mosquitoes is reducing or eliminating the containers which are the source of the problem. Draining or removal of water holding containers, even on a localized basis, will produce remarkable long-term reductions in mosquito annoyance.

The list of breeding sites is extensive and includes any water holding containers, but the primary sites in residential areas include tires, buckets, cans, bottles, boats, flower pots, bird baths, outdoor statuary, ornamental pools, rain gutters, plastic or canvas tarpaulins, children’s toys, rain barrels, and pet food and water dishes.” (3)

Promotional Activities by MCBP for Standing Water Removal

It is certainly appropriate that MCBP should promote non-toxic mosquito control, as referenced within the comprehensive plan. Standing water removal, should be a major component of the non-toxic activity to be promoted, and can be used by all local residents and businesses. Public promotions have been a strong point in the MCBP, and all of the various non-toxic mosquito control activities will readily mesh within these promotions.

Suggestions for Promotional Activities

Graphics illustrating standing water removal can be included in slide shows, in hand-out flyers, and publications from MCBP. Examples of these kinds of graphics are included herein. Such promotions should be targeted to the mosquito season, spring-summer-early fall, emphasizing springtime. During this survey, several good promotional techniques were noted:

> Enclosing flyers on standing water removal with utility bills, water bills, in local newspapers, etc.

> Getting local support: community associations, civic groups, Lions Club, scouts, schools, etc.

> Easy-to-read graphics seems to help promotions.

In addition to graphics, there are numerous examples of lists promoting standing water removal.

These lists contain many details, such as: emptying birdbaths and flowerpot trays weekly, cleaning rain spouts and gutters, draining children’s wading pools and toys, removing debris—especially old tires, and toys that hold rainwater, clearing ditches and filling depressions. Do not overlook small sources of water such as vases, flowerpot saucers, and roadside ditches that may have only one-half inch of water that is constantly present.

Locate and correct hard-to-find areas such as clogged gutters and rainspouts, partially clogged culverts, depressions under decks, sheds or buildings mounted on pilings. Stored boats should have their bilge drain plugs removed, and any water-pockets in their tarps should be emptied. Thoroughness is important, and the goal is to eliminate any water areas which do not dry up within four days.

The Old Tires Problem