Beach Beetle Bonanza

Hello everybody! Kouchibouguac has been treating us well; no mountains, nice neighbours, amazing ice cream, and lots and lots of insect diversity, just the thing for us bug-sters. Today, we hand collected on the Kouchibouguac dunes, at a place called Kellys Beach. When we first showed up, the pickings were sparse indeed, a beetle here, a hemipteran there, but nothing really spectacular. When we began crossing the bridge leading further out into the dunes, however, we began crossing over into an insect gold mine. Every few steps we found a new kind of beetle, interspersed with different jumping spiders and so much more. The bridge itself acted as a sort of collecting sheet during the high winds off the water, intercepting the bugs during their flight.

A blue Coleopteran hiding amongst a pile of March Flies on Kellys Beach, Kouchibouguac National Park.
A blue Coleopteran hiding amongst a pile of March Flies on Kellys Beach, Kouchibouguac National Park.

When we crossed the bridge, the diversity dried up again. All we could find was ants, and even with all of their numbers, we couldn’t find a single ant lion larva. This kept up for a bit, until Martin suggested that we cross the little grassy part we were on and go by the sea. I didn’t think we would find much by the seawater; after all, almost all of the things we have caught so far have been associated with fresh water streams or forests. I couldn’t have been more wrong. Chunky, hard shelled weevils patrolled the sand, while under every clump of seaweed we found hundreds of pretty shiny beetles. We caught orange ones, green ones, iridescent blue ones, huge black click beetles, and a wide assortment of various other nondescript beetles. It was amazing! The entire shore line was covered with seaweed and beetles, and there could easily have been thousands, or maybe millions. More amazing though, in my opinion, is how I think their little niche ecosystem works.  The seaweed we found the beetles under was right by the tide, which should bring in moisture and fresh weeds to feed on. However, as the tide changes, the beetles would either be left on the sand to desiccate, or be overtaken and drowned by the sea. The only possible explanation I can see to explain their survival is that this hidden community of detritivorous beetles follows the tide up and down the beach, staying just out of the way of both extremes. Beetles are exceptional at holding in moisture, and when assisted by the reflectivity of their shells, they can survive for a time on the beach. All things considered, these little guys are probably the favourite thing I’ve witnessed on the BIObus so far, and I can’t wait to see what else shows up.

Graham Ansell, Martin Zlatkin, and Katelyn Lutes collecting on Kellys Beach, Kouchibouguac National Park.
Graham Ansell, Martin Zlatkin, and Katelyn Lutes collecting on Kellys Beach, Kouchibouguac National Park.

To illustrate the skill the beetles have at surviving right on the precipice of two extremes, let me explain how the march flies fared on the beaches; flies that we affectionately nicknamed Fundy Flies for their masses we saw at Fundy National Park. Somewhere around 30% of the detritus on the shoreline seemed to be dead “Fundy Flies”, while all the live ones were stuck in the sand. It seems that they either get trapped, or fly directly into the ocean and drown. The Fundy Flies may demonstrate how well the little shiny beetles have adapted to their current home.

– Graham

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