The battle against Aedes solicitans, the notorious salt marsh mosquito that plagues residents of Essex County continued this year. For the second year in a row the staff at ECMCP launched its attack on this dreaded pest from the air. Intensive ground work coupled with aggressive and extremely precise helicopter maneuvering helped us target local area hotspots in the coastal marshes of Ipswich, Salisbury, and the newest member to our aerial larviciding program, Newbury.

The relative successes we've enjoyed with our air spray program in both 1995 and 1996 seem to be related largely to our unique approach in application method. An integral part of the program in both seasons, has relied upon the inclusion of the ground surveyor in the actual application procedure. This decision was made based on the fact that breeding areas are not etched in stone, as inconsistent tide range, fluctuating fish populations, and the intricacies of each marsh has proven. The

incorporation of individual tide specifics into each application has been extremely helpful in pinpointing control efforts.

Control efforts are maximized by precisely directing the material. This often requires daredevil helicopter acrobatics. The confidence and determined accuracy with which the pilots fly should not be overlooked when contemplating the successes of the aerial larviciding program.

The helicopters flown this season were Bell Jet Rangers. The ships were equipped as before, with a simplex spray system housing 14 raindrop style nozzles, size RA8.

We chose to use the liquid form of Bti as we had in 1995. The sensitivity of local communities to pesticide use, lack of available dry storage space, familiarity of handling, as well as monetary factors contributed to this decision. A previous history of relative success with the liquid formulation (overall efficacy for the 1995 season was in the ninety third percentile) further increased support for the selection of this material.

Once again, maximum label rates were applied due to the potential for massive populations, evaporation of material, and the possibility of poor penetration through thick marsh vegetation.

There were several new facets to the air spray program this year. Perhaps the most significant aspect was the closing of a major coastal gap by enlisting the town of Newbury into the air assault. The Project also purchased a water tank and trailer unit.

The double tank, trailer mounted unit consists of a REAR's 50 gallon skid tank sprayer, a Snyder 200 gallon Champ leg tank, a 50 foot manual rewind reel, and two pumps. The first pump has a high pressure/low volume output for spray applications. The second pump has a high volume/ low pressure output for rapid refills.

The ability of this second pump to quickly replenish supplies of mixing water was essential to the success of ground operations at the loading site. Quite often a new batch of material was required within a brief ten minutes from the last reloading. Therefore, careful coordination of the ground crew was imperative. The capabilities of the water tank and its unit were complimented by our competent ground crew; both proved suitable to the application.

In order to improve the successes of our air spray program we decided to step up our ground surveillance efforts, hoping to obtain a greater knowledge of breeding populations. Due to the extensive areas of marsh in question and the unpredictable effects of tide range, the more you know about where, when, and how much breeding is occurring, the more effective your control can be. Intensive field surveying commenced, largely by means of extended work days.

The location of several recoverable dip stations were moved to more productive breeding areas and areas of easier access. We added a few control dip stations in order to get a broader picture of normal larval survival. We also increased the number of recoverable dip stations, (RDS), from what seems in retrospect a scant ten to a minimum of twenty in both Ipswich and Newbury. All these areas were vigilantly scrutinized throughout the course of the summer, providing us with a much larger scope of breeding data than before. As a result, our widespread applications have become that much more site specific.

You may have heard the expression, "So much marsh, so little time." My response to this is.....ROKON. The Rokon is a 2 wheel drive motor bike that enabled us to cover more ground than ever in shorter periods of time. With minute windows of opportunity for successful treatment due to the nature of Bti, time is as ever a crucial factor. The Rokon's ability to readily traverse vast areas of unknown marsh, without damaging its fragile surface, was in all ways beneficial to the surveillance program. Besides all this, the Rokon is simply a blast to operate.

In the process of extending our knowledge of existing breeding area, we have also expanded the amount of acreage that requires treatment. In 1995, between the 2 towns of Salisbury and Ipswich, a total of 2,254 acres was treated. In 1996 between these 2 towns, that amount was doubled and then some. With the addition of the town of Newbury, total acres sprayed this season ranged near 8,000. We actually exceeded the predicted amount of Bti stores needed by mid July. Fortunately we were able to secure enough additional stores of Bti, thanks to an extremely generous loan from the Plymouth County Mosquito Control Project, to complete our final applications.

When comparing the spray season of 1995 to that of l996, several factors must be taken into consideration. The weather and tides in particular are the first things that come to mind. In 1995 we experienced a relatively rain free season, and a total of three applications were initiated following full flooding tidal events. However, in 1996 we were inundated with rain throughout the summer. Tidal events this season were not nearly as cooperative either. Partial flooding coupled with consistently untimely rains resulted in nearly twice as many applications than previously.

Inclement weather also contributed to the postponement of scheduled applications. An early morning dense fog prevents one from seeing the landing area as well as application targets, perhaps even more importantly trees, power lines, and houses. Heavy rain also limits visibility and can conceivably dilute your material enough to produce poor results in efficacy. We learned this the hard way.

High winds are not something I ever wish to contend with again. For one, it is extremely difficult to direct material into restricted marsh areas, which frequently need the most attention. For two, it is simply not very safe. Spraying in high winds can make an already unpredictable flight, pure madness. A large part of one morning was spent flying sideways at best. I really hadn't thought much about this until Ray, our truly competent pilot, in the process of reloading, looked across the runway and exclaimed in disbelief, "That's a thirty knot wind sock and it's straight out!" We called off the application after that load. I was delighted to find myself stepping onto solid ground a few minutes, seeming hours later.

I want to catch you up on the status of the "No Spray" properties that I had mentioned last year. If you recall, particularly in Ipswich, there are vast areas of breeding marsh that go untreated due to their "No Spray" designation. For the most part, this has gone unchanged. There is hope however. The Parker River Wildlife Refuge on Plum Island has granted us a permit allowing Bti applications to the salt marsh, with exception to the salt panne areas within its bounds. Also, the Trustees of Reservations, one of the largest property owners to exempt their land from spray, have agreed to consider applications of Bti following completion of a study that has been set up in conjunction with the Harvard School of Public Health.

The study was established to obtain data relevant to any detrimental effects of Bti applications on aquatic, semi-aquatic, and terrestrial invertebrates, as well as aquatic vertebrates (mainly fish). Core sampling, water column sampling, and vegetation sampling were conducted on 3 consecutive plots; one treated, one buffer, and one control. Each plot measured roughly 300' by 300'. Though the data has not been compiled for final analysis, preliminary findings have shown that mosquitoes were indeed dead on the treated plot and very much alive on the control plot.

In the "Strategies for the Future" department: stepping up ground surveillance to a level of insanity seems in order. I cannot stress enough how important it is to know the marsh that you are targeting, intimately. This also has an added benefit of requiring extensive use of the Rokon, especially since it doesn't look like I will get the army of eager interns I requested last year.

With two years in the helicopter seat under our belts, the marsh has become more familiar and easier to spray. I would like to sit down with the stereoscope and collection of professional air photos we acquired last year. Recognizing the marsh from a bird's eye view ahead of time helps you pick out hotspots and heavy breeders readily. This results in efficient and accurate application. Both the ground surveyor and the pilot can only get better at this through repetition.

In "Other Notes of Interest" department: it may come as no surprise to you that neither Jack nor I have won the air sickness battle. Initially we thought we had it knocked, however, prolonged periods of nauseating flight time were logged this season, due to the increase in treated acreage. It doesn't appear that flight time will be decreased at any point soon.

There is a slim chance that the last coastal gap in the air spray program may be closed by enlisting the Town of Rowley. This possibility seems overwhelming right now. Frankly, the thought of adding more unknown salt marsh acreage to the program is somewhat horrifying, but in reality, if Rowley were to join up, it could only help the town and its adjacent communities in mosquito abatement.

Last summer is filled with memories, both good and bad. Perhaps the most unforgettable recollection that comes to mind occurred on July 4th. Here's the scenario: Jack finishes up his early morning applications in Ipswich, Ray and I take a load out of the Ipswich landing zone, apply that and head over to the airport at Plum Island, our staging area for Newbury. While awaiting the arrival of the ground crew and equipment, Ray makes a spot check on the engine and ship. Fortunate for us that he did because the driveshaft grease boot on the main rotor had let go.

I have this vivid picture in my mind of cowls, bolts and brackets everywhere. A tense morning and afternoon, filled with an occasional downpour, lots of expletives (deleted here), a couple of scunned knuckles, a few Italian subs, a parts run to Portsmouth, several of those fabulous chocolate chip cookies, and about 8 hours later the ship was back in order. These guys simply did not give up.

Here's my point. In my opinion the successes we've enjoyed with our aerial larviciding program have come largely through just this same type of devotion. Long and quite often strenuous hours of dedicated effort on both the staff at ECMCP and the crew at Joe Brigham Inc. have paid off. Even in the midst of dwindling hope, frustration, and pending failure, we have pushed on with a firm belief that this program can and will succeed.

Despite the wicked poor hand of cards that were dealt this season, we endured and actually came out on top. Lots of larvae, both live and dead have been counted. Numbers have been tabulated. The results are in. In 1996 efficacy has been calculated out to an average value of 83.3 % for the aerial larviciding program.

At one point this summer, good control was obtained even after treating a particularly allusive batch of third and fourth instar larvae. The cynic in me taunts "Ahh, you're just lucky." I suppose to some extent that can't be denied. There's a bit of luck in anything. Nevertheless, panic stricken calls of desperate nature were way down this season. Complaints of "I can't even leave my house!" or "My dog just got carried away ...!" were few and far between. Overall, the number of hysterical screams "SPRAY ME ... PLEASE! please please please please!" have dropped dramatically. Adulticide use was cut literally in half this summer.

Recently, the ECMCP's Board of Commissioners voted unanimously to compliment our staff for the "OUTSTANDING SUCCESS achieved during 1996..." We also received a letter of appreciation from the Town of Georgetown, commending the staff at ECMCP "for the splendid job" we've been doing. Possibly these unprecedented phenomenon imply what mere numbers can't. We are at the very least on the right track.

In conclusion, on behalf of the staff at ECMCP, I would like to extend wholehearted thanks and deepest gratitude to the dedicated crew of Joe Brigham Inc.. Without their patience, sincere interest, and accommodation to our frequently hectic schedule, this program may not have gotten off the ground. Extra special appreciation must go to Ray our pilot, for above all ... not crashing.

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