INSECTS IN HIDING

Wednesday, July 23, 2008

There was a beetle on my computer screen the other day. Actually, it was a colour photo of it that arrived by e-mail, from a Cressy resident, who wrote, ".....never saw one of these before. Can you identify it?"

I don’t pretend to be an entomologist, but with the assistance of my limited library on insects, together with some help from the Internet, usually I can struggle along until I get an identity. The unusual colours on this one had me stumped, so I forwarded his message to a local entomologist who has bailed me out before on more than one occasion. Within a day, I had a reply, and the insect turned out to be a ground beetle. Somehow I was expecting something a little more profound than that, but given there are some 3,000 species of ground beetles in existence, and my insect guide showed only two species, we were both quite happy with the identification as it stood.

Unless it is a giant waterbug or something else that is quite large and obvious, many insects are just too darn small or concealed to be noticed by many people. You do have to keep your eyes open, and I am learning to do just that as I try to become more proficient in the fine art of insect identity. I am always reminded of the young boy who delivered a jar of water to me one day in the Visitor Centre when I worked at Sandbanks as a Park Naturalist. Wondering why a child would bring me water, he then pointed to something very tiny in the corner of the jar which I couldn’t see until I pulled out my magnifying glass. There, bouncing and bobbing around, its tiny legs trying desperately to keep its minute pin head sized body upright, was a red water mite, so tiny as to disappear from sight once the magnifying glass was removed.

It’s a matter of keeping your eyes open. Somehow I missed spotting the culprit who completely defoliated our snowball bushes earlier this spring, leaving a pair of robins embarrassed at having their nest so thoughtlessly exposed. When the leaves returned, I was ready this time with my magnifying glass and discovered an infestation of Viburnum leaf beetles, miniatures insects that seem to fly away the moment they sense your interest. The leaves are disappearing again, and so are those on the highbush cranberry.

Guided hikes are great for finding small stuff, as there are more eyes to spot things. On one such hike recently, someone pointed out a tiny insect perched on some trail side vegetation. At first, all I could see was a finger - then, there it was - a miniature walking stick, barely exceeding the length of a fingernail. Unlike adult walking sticks, this one was green, a clever method of escaping detection during the insect’s vulnerable weeks of evolving into an adult. This youngster had probably emerged from one of many eggs, dropped singly on the ground earlier by the female. The nymphs, upon hatching, clamber up on woody vegetation where they feed, hopefully unnoticed by the myriads of larger insects and birds that also feed in the same habitat.

If this little, green walking stick is fortunate enough to make it to adulthood, it will have picked up many useful techniques along the way on how to escape detection. As walking sticks become older, they become more like their namesake, and have the ability to remain motionless for long periods of time. Even then, they may let their guard down and become a food item for something larger. Their long legs become vulnerable in such attacks, but over thousands of years walking sticks have evolved to regenerate lost legs. Certainly an amazing survival technique.

Walking sticks are no strangers to most of us, but they are more common in the south where some species can reach the length of a person’s outstretched hand. And in areas like this where these insects are so common, the sound of the females dropping their eggs on the ground from the vegetation above is not unlike the pitter patter of light rain.

There are some amazing insects out there. One of the most incredible is the bird dropping moth which perches on an object in such a way as to allow its coloured wings to droop over the edge of its perch. The longer it perches, the more relaxed the moth becomes, and the more it resembles an actual bird dropping. So talented is the insect with this gift, it seems to deliberately choose perches that offer the dripping effect. My first introduction to this insect was on the doorknob to the Visitor Centre at Sandbanks many years ago. I carefully avoided what I thought was an actual bird dropping as I entered the building, but it took two student staff members who were obviously more observant than I was to point out that it was, in fact, a cleverly disguised insect. Since then, I have paid more attention to the bird droppings on my car. The spots on the hood I ignore, but the one dribbling down the side rear view mirror I gingerly allow to crawl onto my finger.