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Watch Out Aphids!

Watch Out Aphids!


Everyone wants to go outdoors in the spring to enjoy the sunshine and the warm breezes. But what is there to do besides sit, or play ball or ride bicycles? Of course there is always garbage to pick up. After that maybe some of the dead leaves and other plant debris can be removed to tidy up the garden a bit. But wait! Under many of those dead leaves we discover adult lady bugs waiting for summer and their favourite food, aphids. There are no aphids to eat just yet as new leaves have not emerged. Let’s allow the lady bugs their peace and quiet a while longer. Soon after the fresh green leaves appear, aphids will be there on some of them and the lady bugs will surely find their way to them.

Immature ladybugs (the larvae) are spiny, wrinkled looking creatures. Few people realize these will mature into adult lady bugs. Some people call these larvae “aphid wolves.” Guess what they eat? You’re right! Aphids! The aphid wolf spends its life gulping down aphids. And it doesn’t know when to stop. Even when it is crammed full of food, it keeps on eating. Now, however, it just takes a bit out of each victim. Each aphid wolf can kill about 500 aphids every day. If the season is dry, and aphids are scarce, the lady bug larva switches to flowers, feeding on the pollen of dandelions and other tasty treats. Within five weeks the aphid wolf sheds its coat three times. Then it glues its back end to a leaf or twig and quietly waits for about ten days. And voila! An adult lady bug emerges. The adult too has a wide mouth and jagged teeth. Aphids taste just fine to these adults too. Female lady bugs lay masses of oval eggs on leaves. Usually the clever mama lays them near a thriving colony of aphids. The lady bug eggs hatch in a few days and the young begin to feast.

Lady bug beetles are found worldwide. Different species can be identified by the arrangement of spots on their wing covers. You can be part of a Canadian project to identify and report the lady bugs you see in your area. Beautiful colour pictures and other information can be accessed on the internet at http://www.schoolnet.ca/vp-pv/coccinelle/e/ladybuge/ladybugs/bugmap.htm. Wow. What a mouthful. If you are on line, why not take part in the survey?

All this talk about eating aphids reminds me of more bad news for these victims. Have you ever noticed insects with large green delicate wings? These insects are about 1 cm-2.5 cm long. Green lacewings (as they are called) are delightful to find. Their bodies and wings are pale green and their eyes are bright gold, brassy or reddish in colour. These are common insects which may be found on grass, weeds or shrubs often in quite open areas. They fly at night but may come to an outside light left on in the dark. You may find some nearby in the morning.

These insects look so dainty, but they are really tough. The common name for immature lacewings is “aphid lions.” Guess what they eat? The lions are wrinkled, hairy creatures not at all like the delicate appearing adults. With sharp jaws the lions pierce the body of an aphid victim, inject protein dissolving juices, and drain the victim’s insides – all within about a minute. Then, perhaps, in order to extract all possible benefits from the victim, the aphid lion hooks the victim’s empty shell, like a trophy, onto stiff hairs on the aphid lion’s own back. The predator thus slinks around covered with skins of its victims and bits of bark and other debris. Birds, looking for an insect snack, will never guess that under the garbage lurks a potential mouthful. Aphid lions move quickly on relatively long legs and they grow up fast. Within 10-30 days the aphid lion ties itself to a leaf with silk it has produced and it forms a pea shaped cocoon. About three weeks later, the adult emerges. It is a true work of art and an engineering masterpiece as well.

Adults still hunt aphids. Yum, yum. The dainty wings are relatively big however so the adult flies fairly slowly. However it has a couple of methods for avoiding predators. One is its strong smell, much like garlic. Yuck! Some predators don’t fancy such a meal. But bats are different. They fly at might as do these insects and they would be happy to eat lacewings. Picture the scene. A lacewing glides gracefully through the night air. Suddenly a bat approaches, moving fast. However the lacewing has special warning devices. In each of its front wings there are incredible ultrasonic sound receivers. Imagine how small these must be. Anyway, forewarned of disaster, the lacewing folds its wings and plunges, about 2 m per second. But bats can dive too. Here comes the bat, closing in fast! At the last second the lacewing does a quick flip, changing its path. The bat streaks past and the lacewing continues its interrupted journey. Another special talent of lacewings is the dainty eggs the female lays on leaves or twigs. With her back end, she dabs sticky material onto a suitable surface. Then she stretches the material upward into a long thread. At the top she lays a single egg. Over a period of a month she lays hundreds of eggs. Each one hatches within about ten days. The interesting thing is that the long stems prevent the first hatched “lion” from eating all the remaining eggs. S/he can’t reach them. What a family! Anyway, the action of dabbing and stretching must be tedious for the mama lacewing. But it is worth the effort, isn’t it? Look, here come more aphid lions to feast on you know what. More seriously, have you ever stopped to consider the wonderful design of each one of God’s creations? Why not make a list of the special features which the lacewing enjoys. Could this insect survive without any of these behaviour patterns and special machines? These truly are gifts conferred on this insect. Without them there would be no lacewings to make nature more interesting. There would also be lots more aphids and perhaps fewer plants since aphids consume plant juices. The entire ecosystem fits so well together. See if you can identify another insect with different special talents. Draw a picture of the insect and make a list of the talents. Tell your friends about your discoveries. After all, I just shared my information with you.

July 1999

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