Urban Grains

If anyone had walked by Cedar Isle farm in the week of June 4th, they would have been understandably confused by the eight 2m by 30m strips of freshly mowed grass. Should they have decided to remain, and looked closely, they may have noticed a strangely colored beetle crawling around. This beetle would have been one of hundreds that were released as part of a research project carried out by Simon Fraser University, in collaboration with the University of Fraser Valley and Agriculture and Agri-food Canada.

My name is Joyce, and I am a graduate student at SFU, studying the use of pheromone (scents used in animal communication) in the control of the dusky click beetle. The larval stages of click beetles, the wireworms, are a pest of many root crops in both Europe and North America. They enjoy feeding on the parts of the plant that are underground, which creates tunnels in the crop that make them unmarketable. They are especially a big problem for potato farmers. Many of the insecticides that have been used previously in wireworm control have been, or will be banned because of environmental and health safety concerns. Because of this, there is a great need in developing alternative forms of control, and one such solution is to use a granular form of pheromone to attract them to a fungal insecticide. To see how effective pheromone granules are in attracting beetles, I decided to find out how far away they can attract beetles from.

Amanda and Chris marking out beetle release points

To investigate this, my team and I packed up our bags at the end of May and set out to Cedar Isle farm to set up our field site, which Jim kindly offered to us. We created 8 strips of grass, to which we were going to introduce into the middle, a band of pheromone granules. The plan was we would release beetles from different distances, and see which ones we got back. We would do this in two ways: firstly, by setting up pitfall traps to trap beetles that reach the band and secondly, we would crawl on our knees and look for beetles.

Chris, checking pitfall traps. Pitfall traps are traps made from plastic cups that are installed into the ground so that the rim is level with the ground. When an animal falls in, they can’t escape because of the smooth wall created by the sides of the cup.

Sara playing hide and seek with beetles. To save us from having to look for beetles throughout the entire field, we only look for beetles within a wooden frame, of which we put down at certain points in the field. The frame is further divided into a 4 by 4 grid to make searching easier.

Prior to our experiment, we spent 2 weeks painting hundreds of beetles individually in different color combinations, in order to tell apart the different beetles. By June 4th, my team made up of Tamara and Amanda from SFU, and Chris, Sara and Aaron from UFV set out to put the finishing touches to our plots, so that it would be ready for the experiment that would begin the next day.

We painted over 2000 beetles, coding for 64 different treatments.

At 6am, we said goodbye to our 2300 painted beetles, and released them, not knowing whether we would ever see them again. We split off into our respective tasks; Chris was responsible for checking pitfall traps. Tamara, Aaron, Sara and I were responsible for looking for beetles on the ground. We were in motion, and working like a well-oiled machine. We surveyed every hour, and we continued on for 24 hours. Happily we greeted over 200 our beetles in our pitfall traps, just half an hour after we released them. The pheromone was working! Over the course of the 24 hours, we managed to recover almost half of the beetles that were released. What was surprising was that we had 19 cases of beetles moving between strips. This means that they were moving distances of over 20m!  Who knew little beetles could travel so far? Unfortunately, the ground searching team only found a total of 15 beetles. The beetles were just too good at hiding.

It is promising to know how effective the pheromone is in drawing beetles in, and it is my hope that in the future we will have a safe and easy alternative way of controlling wireworms. Thank you so much Jim and Diane, for providing us with the best field site someone could ever ask for, and also a huge thank you to Harprit and Amanda for assisting in setting up the field, and Tamara, Chris, Aaron and Sara for taking part in our marathon experiment.

Joyce

Aaron doing a side experiment on slug slime patterns on portable toilets.

Sara catches some Z’s whilst Tamara enjoys a book

Aaron and Chris squeezing in some electronic battleship in between observations

The Dream Team! It’s clear that some of us were in better spirits than others at the end of our marathon experiment.