Friday, May 2, 2014

UST GS: You can actually hear death knocking in the night.

Dr Abe V Rotor
Living with Nature - School on Blog
Paaralang Bayan sa Himpapawid with Ms Melly C Tenorio
738 DZRB AM, 8 to 9 evening class, Monday to Friday
It’s like an Edgar Allan Poe’s story of death tapping on “a night dark and dreary”, but in this case it is not a raven. It is the Death-watch Beetle (Xestobium rufovillosum) that is alluded to death. It is an insect with a scary habit all right. The name was derived from the tapping sound it produces, which is frequently heard during mating period, usually in April or May.
Death-watch Beetle - the harbinger of death 
Photo acknowledgement: Wikimedia Commons.

The beetle simply jerks its body forward in rapid succession, and strikes each time with the lower front part of its head against the surface on which it happens to be standing. It gives eight taps in slightly less than a second; and almost before it stops another beetle of its kind that is within hearing distance will respond by tapping back in the same quick manner. In woodworks and furniture that have been attacked by the Death-watch Beetle, the worm holes are large and distinguished by the presence of frass and powder around the openings.


Powder post beetle or furniture beetle

The beetles are from one-fourth to one-third of an inch in length, dark brown in color, spotted and banded irregularly with thick patches of short yellow gray hairs. Pairing takes place after the beetles have made their exit from the wood, and they die a few weeks later, the female in the meantime having laid some 70 eggs. The tapping is of the nature a sexual call, and may be repeated over and over for quite a long time. Grating sound may also be heard as the larvae gnaw on wood inside its tunnel. It takes three years to complete the insect’s life cycle. A more familiar beetle, Anobium punctatum, is called powder post or furniture beetle, named after the dust it scatters at the mouth of its tunnel on furniture.


Next time you hear death knocking in the night, think of it, it is just coded expressions of insects in love. ~
 Powder around the holes (left),  leading to the tunnels (right).

No comments: