Connecting people with nature in Ontario's Mississippi Valley

Beetles on the Ground

Beetles on the Ground

Thursday, October 18, 2012

Beetles—the Group Everyone Knows

Ground (carabid) beetles typically hide by day under logs, or among rocks by the edge of ponds and rivers. The shiny black or metalic backs of these predators dart across the soil surface while we are asleep. Some reach sizes of 30mm while others (in relation to their body length) are among the fastest land animals on Earth. Have you spotted them?

The Mississippi Valley Field Naturalists’ (MVFN) 2012-2013 public lecture series, Nature Beneath Our Feet, continues with the second presentation October 18, “My Favourite Insect Group—Ground Beetles (Carabidae).” You do not need to be an expert to enjoy the presentations—just possess a curiosity or appreciation for wild nature. Cottagers, hunters, fishermen, canoeists, hikers, campers, artists and seasoned field naturalists alike will find something to interest them as we explore what lives in Lanark County and how best to protect it for future generations. Refreshments are offered at each lecture.

This month’s lecture will be presented by Dr. Henri Goulet, research scientist emeritus with Agriculture and Agri-Food Canada. Henri will give us a tour of the diversity and beauty of his favouite group of insects, which will be generously illustrated with species found in Lanark County.

Not surprisingly, the formative years of many great biologists, such as Charles Darwin, included the study of beetles. Beetles are easy to recognise and are attractive subjects for study. The 350 million species worldwide are found from pole to pole. There are more named species of beetles than there are named species of any other group.

Ground (carabid) beetles, in particular, contribute 1,700 species to the insect fauna of North America. Typically they hide by day under logs, or among rocks by the edge of ponds and rivers. The shiny black or metalic backs of these predators dart across the soil surface while we are asleep. Their diet varies wildly from the insides of snail shells to springtails (the hopping “black specks” on the snow on mild winter days). Some reach sizes of 30mm while others (in relation to their body length) are among the fastest land animals on Earth. Have you spotted them?

Consider just one amazing group of ground beetles—bombardier beetles. These bluish or black little beetles, with reddish-yellow legs, are like skunks of the insect world. When threatened, they point the tip of their abdomen toward the intruder and release a blast of hot (100oC), caustic chemicals. The beetle’s abdomen acts like a two-chambered gun. When the chemicals are mixed with enzymes, heat and oxygen are produced and the material is explosively propelled from the anus with a notable pop.

It is easy to understand why Dr. Goulet fell in love with ground beetles and would like to share his repertoire of intriguing beetle secrets in his MVFN presentation, “My Favourite Insect Group—Ground Beetles (Carabidae),” at 7:30p.m. on Thurs. Oct. 18, 2012, Almonte United Church, 106 Elgin St., Almonte. All are welcome ($5 fee for non-members). For further information please contact MVFN’s Program Chair Cathy Keddy at 613-257-3089.

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