In my assessments the caterpillar appears to prefer green ash, poplar, birch, willow, and maple which compromise a significant portion of urban forest inventories.
Having a short zone 3a growing season most trees start to generate leaves in May and don’t recover after a June/July outbreak which leaves the city bare of foliage and shade cover. The few trees that are not affected such as elm shed leaves in late August and start to enter natural hibernation.
Statistics show that there have been larger outbreaks but my concern is with the changing lengths of summer and winter there is a shorter and shorter period of non-defoliated time which may harm tree health during peak cycles.
Environment Canada (1984) released a fact sheet about four species of tent caterpillars across Canada including the forest, eastern, western and prairie. The report indicates some positives such as the rarity of long term tree damage but also suggests significant economic and social concerns such as trains being delayed, motor vehicle accidents, and social paranoia. From an environmental perspective I am also concerned about the homeowners misuse of homemade remedies such as cooking oil, vinegar, and a variety of toxic insecticides available to the public such as malathion.
Image 1: Wood, J. (2016, May 19). Caterpillars a pain for Lloydminster residents. Retrieved April 13, 2018, from https://www.mylloydminsternow.com/7041/caterpillars-pain-lloydminster-residents/
Image 2. Martell, C. (2017, May 31). 'They just keep coming': Tent caterpillar invasion coats Sask. home in insects - and feces | CBC News. Retrieved April 13, 2018, from http://www.cbc.ca/news/canada/saskatchewan/tent-caterpillars-rm-dundurn-1.4139552
Resources See Canadian Forest Service Fact Sheet on Tent Caterpillars
Potential Consultations
DR. A. C. (Ale) Costamagna - Entomology, University of Manitoba - Ale_Costamagna@umanitoba.ca
DR. R.W. (Rob) Currie - Entomology, University of Manitoba - rob_currie@umanitoba.ca (On leave until July 2018)
Iain Phillips, Secretary - Entomological Society of Saskatchewan - iain.phillips@wsask.ca
Bette Beswick, Vice-President - Entomological Society of Alberta - bette.beswick>gmail.com
