Insects and Disease
2011/12 Summary of Nisga’a Mountain Pine Beetle Program
In April 2011, Corporate Services Division of the Ministry of Forests, Lands and Natural Resource Operations approved a $1.05 million 5-year budget to address provincial forest health obligations (specifically for Mountain Pine Beetle) required in the Nisga’a Final Agreement. The Kalum North Coast district initiated a suppression program over the control area within the valley corridor from Kitsumkalum Lake to New Aiyansh during the fall of 2011. The budget for 2011/12 fiscal year was $250,000.
Preparation work in the district began in September 2011. Aerial detection data collected in 2010 was examined along with data from provincial forest health overview flights to estimate MPB rate of spread during the summer of 2011. The summer of 2011 set a record in the district as the coolest and wettest according to meteorological records. MPB life cycles require minimum temperatures for flights and reproduction. The only window that occurred during the summer of 2011 was during the first 2 weeks in August where temperatures reached the mid twenties.
On November 18 the district conducted a helicopter flight of the suppression area. The flight was delayed for 2 months due to rain and foggy weather throughout the fall. When the flight eventually did occur, much of the tree canopy along the valley was covered in snow which made the detection of red attack trees difficult. The flight was a success however as the detection data from 2010 was used to locate previous and current attack centres. In total 196 red attack sites were recorded during the flight.
Attack ratios (current attack : red attack) less than 1:1 and greater than 3:1 are not recommended for treatment as beetle activity is either below active thresholds or beyond control efforts. The results of the data collection averaged an attack ratio of 0.23:1, well below the threshold of 1:1. The decision was made to proceed with suppression activities over the containment area. The rationale for the decision was that during the expected low point in the beetle population, control efforts would be especially effective in reducing beetle numbers. If environmental conditions improved in following years, populations would take more time to recover and risk to Nisga’a lands from MPB would be reduced.
Pheremore traps will be installed at any areas of potential concern to maintain beetle populations at endemic levels. Currently no areas of concern are located on Nisga'a Lands, an annual helicopter survey will be completed in August/September of 2013.