A Passion for Beetles

Academy entomologist and Director of Research Dave Kavanaugh combines his two greatest passions-science and being in the great outdoors-into a career that takes him places.

As a young boy growing up on the San Francisco Peninsula, Dave Kavanaugh yearned for family trips into the country where he would wander the rolling hills, forests, and streams in search of butterflies, frogs- anything he could find. Today, this insatiable appetite for nature still fuels Kavanaugh. For the past 30 years, he has scoured wildlands from North America to Madagascar to China for carabid beetles, one of the most diverse groups of animals on Earth. Finding them so conspicuously abundant, he's set out to discover why.

Carabids, or predacious ground beetles, are mostly nocturnal and hide during the day under leaves and rocks or behind loose tree bark, coming out at night to hunt other insects and invertebrates. They occur in nearly every type of habitat and show some remarkable adaptations. For example, species that live on high-altitude glaciers resist temperatures well below freezing; they scavenge snowfields for other insects too cold to move. Other species that live deep underground have lost their coloration, eyes, and wings.

carabid beetle eating snail
Above: Snail eating carabid beetle, Scaphinotus velutinus, Redwood National Park. Photo: Ed Ross. Inset: Carabid beetle Mormolycina oberthuri, Ranomafana National Park, Madagasgar. Photo: Dave Kavanaugh.

 

 

sifting for beetles
Dave Kavanaugh using a pooter to collect from sifted forest litter on a beating sheet, Gaoligong Mountains, Yunnan China. Photo: Charles Griswold.

But the beetles' ubiquity doesn't make them easy prey, and Kavanaugh has had his share of battle scars collecting them. Many carabids employ chemical warfare as a defense mechanism, spraying hot acid from pairs of glands in their abdomens. Once, while chasing a small beetle with a "pooter," a device used like a straw to collect insects, Kavanaugh got a mouthful. The fleeing insect had scurried underneath a larger ground beetle, which blasted its acid into the tube, causing Kavanaugh a fit of hard coughing, but no long term damage.

collecting beetles in snowfield

Dave Kavanaugh collecting carabid beetles under stones at edge of snowfield, Garibaldi Provincial Park, British Columbia, Canada. Photo: Henri Goulet