Impact of European Crane Fly on the Turfgrass Industry in British Columbia

A Snap Shot of the Impact of the European Crane Fly on the Turfgrass Industry in British Columbia – a 2011 Survey of Turf Managers

By Deborah Henderson

Cranefly larvae damage roots and crowns of turf by direct feeding.  As with invasions of other non-native species, there have been crisis events (Williams et al 1989) but eventually new pests become part of the regular pest management expectation. This pest is actually two invasive species; European Cranefly (Tipula paludosa) and the Common Cranefly (Tipula oleracea).  In order to get a better understanding of how turf managers are dealing with these pests, a survey was offered to participants of the 2011 WCTA Conference and Tradeshow in Victoria, BC, with funding from the WCTA Research fund.

Nineteen turf managers participated in the survey. Of the respondents, 42% were managers at golf courses, 16% were sports field managers, and the remainder were horticultural growers and researchers (Fig. 1). Most of the respondents were from BC but 3 were from Ontario and 3 from Oregon. The survey posed questions on the frequency and intensity of infestations, and any chemical or biological control measures used. It should be noted that respondents were not asked to distinguish between species of Cranefly.

Results

The survey results suggested that there is a consistent presence of Cranefly (adults or larvae) in the majority of turf/sports greens in BC. Fifteen of nineteen respondents (79%) reported that the pest had been present recently (Fig. 2), with 31% recording infestation every year, and 26% every 2-3 years.

Figure 2. Number of respondents from different areas reporting recent Cranefly infestations (adults or larvae)

Despite the apparent high frequency of infestations, the pest does not seem to be causing major financial losses for turf managers. When asked to rate their experience of the severity (including financial loss) of infestation on a scale of 0-10, only 6% of respondents reported having had high financial loss. The turf managers reporting highest infestation severity were from sites in Greater Vancouver and Ontario.

The monitoring effort expended for a pest also indicates how serious an issue it is for turf managers. Turf managers do not appear to put forth a great deal of time or resource to monitor this pest:

% of managers using Monitoring method for Cranefly:

• 17% No monitoring for this pest
• 33% Observe and record damage to turf from any root feeding larvae (note, this may not be caused by cranefly larvae)
• 27% Record the number of adults swarming
• 17% Count the number of larvae in a given area

The most popular method of monitoring was to just observe and record damage to turf caused by any root-feeding larvae. The most effective method for  monitoring cranefly larval numbers  is counting the larva in a given area, but only 17% of the respondents employ this accurate method.

The frequency of using control measures for leatherjackets was also low (Fig. 3), with 33% of respondents not using any control measures, ever. The most commonly used control measure was drainage management, with 25% of respondents having taken steps to change drainage patterns and irrigation frequency in order to prevent leatherjacket damage. Chemical controls were used by 13% of respondents, with explanations that chemicals were only used in isolated situations where pest levels were exceptionally high due to poor management in the past. Biological controls (nematodes) were used by 13% of respondents, but efficacy was not monitored.

Figure 3. Frequency of control measures used against Cranefly in Turf

Conclusion

The European crane fly is well established in British Columbia, and is regularly present in commercial golf and sports turfs. Despite the pests ability to damage turf grass and its constant presence year to year, there is not an apparent demand for control options. Even monitoring and use of cultural controls are not common practices unless there have been high infestations at a particular site in the past. Concern about the residual effects of chemical control measures is minimal as chemical controls are not commonly used for this pest. Although the pressure from Cranefly is currently low, there can be years when mild winter conditions allow many larvae to survive, catching turf managers off guard and leaving few options other than chemical pesticides to quickly get the high populations under control. The development of bio controls should focus on dealing with these high pressure situations, as turf managers do not employ controls for low level infestations.

Cited reference

Williams, J., R.C. Eickelberger, and G.C. Fisher. 1989.  The European Crane Fly A Serious Pasture Pest in Tillamook County. Oregon State Univ. Extension Report EM 8411/October 1989

Malcom Storey 2011-12 / www.discoverlife.org  Tipula paludosa, European Cranefly adult

Submitted by Deborah Henderson, PhD
Director, LEEF Regional Innovation Chair and
Julia Ratcliff, Research Assistant
Institute for Sustainable Horticulture
Kwantlen Polytechnic University
12666  72nd Ave.Surrey, BC, V3W 2M8
604-599-3460
deborah.henderson@kpu.ca 
www.kpu.ca/ish