In looking back at my posts over the past few weeks, I realized that it has been far too long since I’ve actually talked about beetles. Perhaps “Petals In The Bush” would be a better name for this blog! I still have some botanical thoughts to get off my chest before the insect season starts in earnest, but until then, and in anticipation of the upcoming summer’s hunts, I offer this fun, light-hearted introduction to collecting and keeping tiger beetles by Peter Schriemer. Pay particular attention to the method he uses to capture these elusive little creatures:
Tiger Beetles are my favorite type of beetle! Entomologist John Acorn got me hooked on these little guys. They live across the country in various habitats, so you may not need to travel far to go on a Tiger Beetle Safari of your own!
Vodpod videos no longer available.
Capturing tiger beetle adults can a little (lot) more difficult than implied by this video. Adults have excellent eyesight, and many species are extremely wary. It takes practice, patience, and lots of second chances. The collecting method shown in the video is what I refer to as the “stalk and slap” method – the beetle is slowly stalked until within net reach, and the net bag is slapped over the beetle. This method works well enough, but it has its limitations. If there are any gaps between the ground and the net rim, the beetle will quickly dart through them and fly away. This is easy to prevent on sandy and soft clay substrates, as the net rim can be sealed against the ground by kneeling quickly on each side of the rim to embed it slightly and using the hands to hold up the net bag and locate the beetle. Still, there are a few things I don’t like about this method – the beetle may hide against the inside of the rim and be difficult to locate, and once found it may be difficult to grab the beetle through the net if it is against the ground (don’t even try lifting the rim and reaching under – the beetle will zip out and be gone). This method can also be taxing on the legs, as each attempted capture involves kneeling and standing back up (getting harder and harder for these 50+ year old knees to do).
The major limitation of the slap method, however, is that it doesn’t really work on hard, uneven surfaces. Many species are found in glades and other habitats with exposed rock substrates. In these types of habitats, the net rim simply cannot be clamped tightly enough to eliminate the gaps (not to mention the added difficulties in kneeling on these surfaces). Because of this, I have adopted a technique that I call the “tap and swipe” method. Here again, the beetle is stalked until within net reach (made easier with a longer handle), but rather than slapping the net bag over the beetle, the rim of the net is tapped against the ground next to the beetle and then assertively swiped sideways to catch the beetle just as it starts flying. A quick 180° flip of the net rim closes the opening to prevent the beetle from escaping, and it is easily seen in the hanging net bag, where it can be grabbed from outside the net bag with one hand to secure it before reaching into the net bag with the other hand. With a little practice, one eventually learns to reach down into the open net bag and grab the beetle while preventing it from flying up and out. All of this can be done while standing, so it’s easier on the knees.
The tap method does require more knowledge about the beetle’s escape behavior in order to anticipate how quickly and in which direction the beetle will fly – some species delay take off just slightly, thus requiring a slight “pause” between the tap and the swipe. However, once their behavior is learned I have found this method to be more consistently successful than the slap method – even on soft substrates. For species that I haven’t encountered in the field before, I use the slap method at first (if I can) until I have a feel for their escape behavior. If I can’t, I use the tap method and hope for the best!
Copyright © Ted C. MacRae 2009