Lesson LXXXIX

The Mother Lace-wing and the Aphis-lion

Leading thought—The lace-wing fly or golden-eyes, as she is called, is the mother of the aphis-lion. She lays her eggs on the top of stiff, silken stalks. The young aphis-lions when hatched, clamber down upon the leaf and feed upon plant-lice, sucking their blood through their tubular jaws.

Method—Through July and until frost, the aphis-lions may be found on almost any plant infested with plant-lice; and the lace-wing’s eggs or egg-shells on the long stalks are also readily found. All these may be brought to the schoolroom. Place the stem of a plant infested with aphids in a jar of water, and the acts of the aphis-lions as well as the habits of the aphids may be observed during recess or at other convenient times, by all the pupils.

Observations—1. When you see a leaf with some white mold upon it, examine it with a lens; the mold is likely to be the eggs of the lace-wing. Is the egg as large as a pin head? What is its shape? What is its color? How long is the stalk on which it is placed? Of what material do you think the stalk is made? Why do you suppose the lace-wing mother lays her eggs on the tips of stalks? Are there any of these eggs near each other on the leaf?

2. If the egg is not empty, observe through a lens how the young aphis-lion breaks its egg-shell and climbs down.

3. Watch an aphis-lion among the plant-lice. How does it act? Do the aphids seem afraid? Does the aphis-lion move rapidly? How does it act when eating an aphid?

4. What is the general shape of the aphis-lion? Describe the jaws. Do you think these jaws are used for chewing, or merely as tubes through which the green blood of the aphids is sucked? Do the aphis-lions ever attack each other or other insects? How does the aphis-lion differ in appearance from the ladybird larva?

5. What happens to the aphis-lion after it gets its growth? Describe its cocoon if you can find one.

6. Describe the little lace-wing fly that comes from the cocoon. Why is she called, golden-eyes? Why lace-wing? Does she fly rapidly? Do you suppose that if she should lay her eggs flat on a leaf, that the first aphis-lion that hatched would run about and eat all its little brothers and sisters which were still in their egg-shells? How do the aphis-lions benefit our rose bushes and other cultivated plants?

Supplementary Reading—“A Tactful Mother” in Ways of the Six-Footed.