Advanced Oracle PL/SQL Programming with Packages

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A moth is featured on the cover of Advanced Oracle PL /SQL: Programming with Packages. Moths, along with butterflies, make up the insect order Lepidoptera, the second largest order of insects. Their wings are largely or entirely covered in tiny, overlapping scales. Moths, unlike butterflies, are mostly nocturnal, yet they tend to fly toward light. An old superstition holds that white moths fluttering around lights in the evening are actually the souls of the recently dead.

The long coil seen on the head of the moth on this cover is the proboscis, a hollow tube through which it sucks up food. The proboscis is actually formed of two rounded tubes joined together by a third tube. When the moth is feeding blood flows through the two outer tubes, forcing the proboscis to straighten. When feeding is done the blood stops flowing to these tubes, allowing the proboscis to coil up and out of the way. All moths and butterflies have such a feeding "tube." Most moths feed exclusively on nectar, preferring flowers that are white or green and that can be seen at night. Their feeding activities make moths and butterflies extremely efficient pollenizers. Some moths, however, have developed proboscises that are strong enough to penetrate fruits. ...