Biological data characterizing T. oleracea biology, phenology, and impacts in Washington State.

The lack of effective larval identification techniques limited the biological investigation aspects of this project to adult monitoring, and efforts to sample adults quantitatively (i.e. emergence and light trapping) were unproductive. As a result, the adult collection data gathered in this project must be recognized as largely random and unquantified sampling, even though hand sampling at light traps was often conducted in a similar manner many evenings throughout the course of the project. However, while unquantified, the catch data does represent a relatively consistent effort to detect and collect adult crane flies present for the purposes of determining the 1999 flight phenology for T. oleracea and T. paludosa. All adult collections for both species are summarized in Figure 10.

The catch data, as expected, does suggest a single, relatively continuous flight period for Tipula paludosa, and two separate flight periods for Tipula oleracea, reflecting the two generations per year biology described for the species in the European literature (Alford, 1991). Tipula paludosa adults were collected from May 5 until September 28, although sporadically and in low numbers from first catch until early August, and high catch numbers during September suggest a peak of flight activity around the middle of that month. Tipula oleracea adults were collected from April 16 until June 25, and August 17 to September 16, with catch numbers during the first catch interval suggesting a possible peak in flight activity in late April.

The widespread distribution of T. oleracea clearly shows that this "new" introduced species has been present in the Pacific Northwest for many years. How it went unnoticed as it became established here and spread throughout the Pacific Northwest is easy to speculate, since it so closely resembles the European crane fly. However, another significant contributing factor is that residents of the region have become accustomed to the damage and costs that "crane flies" inflicted over the last 20 years. The widespread and chronic nature of "crane fly" damage to turf in diverse commercial and private settings in the region is now common knowledge, but the actual economic impacts are poorly described in the technical literature and associated costs have never been calculated or estimated.

For this project, a brief survey was conducted to estimate one facet of the economic costs of crane fly control in Western Washington - that of private homeowner applied pesticide treatments for "european crane fly". Information sources and estimates compiled were as follows:

• Information was solicited from 3 owners or managers of prominent pest control businesses in economically contrasting areas of the Puget Sound metropolitan area (Whitworth et. al., 1999).
• Current estimates were requested by telephone interview for: percentage (range) of homeowners in business area that do their own cranefly treatments, what they use, and average size of lawns.
• The total number of residences in Western Washington used to calculate total estimated costs was from a Washington State Office of Fiscal Management report, Population Trends - 1999 (OFM, 1999).

Other gross/general assumptions for this estimate were: residents applied a single annual treatment for crane flies, and they used the most popular over-the-counter pesticide (Diazinon) at the recommended label rates, and the estimations garnered can be applied to the resident population of the rest of Western Washington (for crane fly prevalence and homeowner action). These estimates and asumptions produced the following calculations:

* - Range of estimates in different areas were; 30-35% (overall in Puget Sound metropolitan area, A. Antonelli), 10-30% (Tacoma - Parkland, suburban and rural Pierce county), 70-75% (Everett - Kent, King and Snohomish counties), 50-70% (Tacoma - Lakewood, Pierce county); Averages for range, low = (30+10+70+50)/4, high = (35+30+75+70)/4, gives average range of 40 - 52.5, mean of which is 46.25

** - Range of estimates, same order of areas as above; 3,000-5,000 ft.², 4,000-5,000 ft.², 5,000-7,000 ft.² ; Averages for range, low = (3,000+4,000+5,000)/3, high = (5,000+5,000+7,000)/3; gives range of 3,000-5,667 ft.², mean of which is 4,833 ft.².