Observation: This tent caterpillar tent was observed along the boardwalk in Rotary Park adjacent to Great Slave Lake. There are many many tents, so many that there are tents every few feet. Considerable defoliation is occurring. Tent caterpillars were also observed near Schooldraw Ave and 44th on wild rose.
Forest Management Consult: Jakub Olesinski, Forest Ecologist, writes, "This is a third consecutive year of this outbreak.The species has been identified as Northern Tent Caterpillar (Malacosoma californicum pluviale) which is a subspecies of Western Tent Caterpillar (Malacosoma californicum). This species has been first recorded in Fort Smith and Hay River back in the 90's but has never occurred at outbreak levels like this current one in Yellowknife. There are reports of the same species occurring at high numbers as far north as Norman Wells this year which is consistent with observations from the last two years. The outbreak observed in Yellowknife in 2015-2017 is unprecedented." Source: Environment and Natural Resources, Forest Management Division. June 13, 2017
Resources:
USDA Forest Service. Forest Insect & Disease Leaflet 119. Revised may 2008. "The first evidence of infestation is the presence of white silken tents in the branches of host plants. These are generally visible shortly after budburst. The tents increase in size as the larvae grow. Later, defoliation of individual branches becomes apparent and, during outbreaks, entire trees and stands can be completely defoliated by late spring."
Natural Resources Canada – Northern Tent Caterpillar Malacosoma californicum pluviale (Dyar). "Defoliation intensifies as larvae mature, and trees often become stripped of foliage by mid-June or early July."
Natural Resources Canada – Gardutt, R., Wood, C.S. Northern tent caterpillar. "Defoliation intensifies as larvae mature, and trees often become stripped of foliage by mid June or early July. Significant damage to the trees occurs only after prolonged severe infestations, and is limited primarily to loss of growth potential and some branch dieback." Source: Canadian Forest Service, Pacific Forest Centre | Revised July 1993 - PDF Version August 2000
