Wednesday, March 31, 2004

cicada rain

saw a Washington Post article about expecting the next brood of 17-year cicadas in early May. Imagine, the eggs for this batch was laid in 1987! This batch was labelled as Brood X (as in #10). So you can expect Washington DC area to be armpit deep in cicadas in May. The report also warned of "memorable" outdoor wedding ceremonies during that time. Bob Dylan even wrote a song about the cicadas (even though he called them locusts??) in 1987, the last emergence.

scientists, naturalists and even common folk knew when certain cicada species in the Northern Hemisphere emerge since they have cyclical regularities. some species have 7, 9, 11 or even 17 year cycles. We use to tell bio students in NUS during entomology classes that it can be judged almost to the day and u can set your deck chair in the garden to wait for cicadas to emerge

we in the tropics should be familiar with cicadas. you can hear the background buzz of cicadas when walking in Bukit Timah Nature Reserve. Cicadas are "True Bugs" or Order Hemiptera, meaning they have hypodermic syringe mouth parts used for sucking liquid food. not to be confused with the American reference to insects as "bugs". males produced the "buzz" with specialised organs along the sides of their bodies. Cicadas suck sap from trees. their juvenile stage, or nymphs, spend their time underground sucking on root sap.

Our army boys were amazed when they encounter huge cicadas while training in the jungles of Brunei. We can't even escape them when in Temburong Camp. Attracted by flourescent lights, they fly indoors and get hit by the spinning ceiling fans. Many NS boys had been ignominously hit by cicada ricochets. My men used to say that they must tell their folks back home how "siong" Brunei training was; even the "houseflies" were fist-sized!

Even in Singapore, we can get sudden emergence of cicadas. Prof Murphy was called out by NParks some time in the mid 90s to investigate a sudden appearance of cicadas in Labrador Park. NParks even provided a cherry picker crane to hoist Prof Murphy to the tree tops to check out the cicadas. There were so many of them on a few trees that the unusual phenomenon of "cicada rain" was seen. Since cicadas filter the dilute sap from xylem vessels, they need to pump out the excess water from their rear end. u can think of it as "cicada pee", not that accurate but close enuff... think of thousands of cicadas squirting out tiny water droplets. The effect was even more stunning on a hot day. the ground near the trees was wet and even the grass patch was muddy. Some of us also went down to Labrador Park to experience it ourselves. it was like walking through a fine drizzle, a bit like air-cond condensation...anointed by "cicada pee"...

traditional chinese medicine also make use of the empty shells of cicada nymphs after the adults have emerged. my mother still brew a soup that is suppose to be good for the eyes and de-toxing using water chestnuts, wolf-berries (good source of Vit. A) and cicada nymph cases.


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