One leaf only (Egg laying strategies)

If you are a gardener, you know something about caterpillars. It is easy to think that caterpillars will eat anything, but a closer study shows this is not the case. The caterpillar is among the most fussy eaters in the world. In fact, for many species of butterfly and moth, the caterpillar will only eat one kind of leaf. Programmed into the brain of the caterpillar is knowledge that tells it which kind of leaf was designed for it to eat. The hungry little caterpillar that just emerged from it’s egg will choose to starve to death rather than eat a leaf it was not designed to eat. So how does it find the right leaf amongst so many different kinds? The answer begins with the caterpillars mother. Instinctively knowing that her little baby is a fussy eater, she chooses to only lay her eggs on or very near to the right leaf. 

A good scientist is always asking questions about what they have observed. Knowing that a mother butterfly only lays her eggs on one kind of leaf raises some questions. Firstly, how does she know which leaf is the right leaf? Knowing that before undergoing metamorphosis she was a caterpillar eating that same kind of leaf maybe gives us a clue. She knows what the leaf tastes like. But how does a butterfly taste, because she has a proboscis for sucking nectar and the proboscis does not have a tongue for tasting and can not suck up a leaf to taste it? Scientists have observed the behavior of butterflies looking for the right leaf to lay their eggs and noted that when they land on a leaf they scratch the surface of the leaf with their foot. This observation lead to the discovery that butterflies taste with their feet.

We still have a problem. A quick look at the natural world tells us there are thousands of kinds of plants each one with many leaves. So how does the butterfly find the right leaf to taste test? The answer is smell? The word smell brings to mind the word nose, but a butterfly does not have a nose. So how does a butterfly smell? Scientists have studied this as well and discovered that the antennae of the butterfly are able detect odors (smells) in the air. In fact they have found that some butterflies can smell the right leaf from several kilometers away. Now that is amazing! I have tried smelling the right leaf with my big nose touching the leaf and I can’t smell anything.

Now lets add up what we have learned. Caterpillars are programed to only eat the leaf that is good for them + butterflies will lay their eggs only on or near the right kind of leaf for their baby + butterflies taste with their feet + butterflies smell with their antennae = a miracle. If the right leaf, the right knowledge, the foot that tastes and the antennae that smells, weren’t all designed at the same time, the very first caterpillars would have starved to death and today their would be no butterflies. We know from the Bible that on the fifth day God created the animals that fly. The miracle happened because God thought it all out ahead of time and made the butterfly with everything it needed so it could find the right leaf to lay it’s eggs on, ensuring it’s babies survival, and ensuring that we would have butterflies to bring joy to our hearts.