Q: Should a newly planted tree five feet tall be staked? Some say yes, others say no. A: Research has shown that a tree standing alone with its top free to move usually becomes a strong tree able to withstand the elements. However, if the wind causes the roots to come loose in the soil, the tree should be staked until it has established a good root system. Q: Some kind of insect is making my bean leaves look like a lace curtain. All I can find on them is lady bugs. Do you have any suggestions? A: What you think are lady bugs are probably Mexican bean beetles; they're second cousins. A spray or two of malathion should take care of them. Directions on the label should be followed closely. Turning the garden hose on them may take care of it also. Q: A few of my sunflowers have died because something ate the roots. Do you know what it is? A: It may be a small, cinnamon brown beetle. Check and if you find it, drench the soil with Spectracide. Follow directions on the label. Next year plant varieties best for bird food. Q: What causes leaves on my birch tree to become wrinkled and discolored? A: It is probably due to aphids (plant lice) feeding on the leaf tissue. They can be seen on the underside of the leaf by opening it so the wrinkled area lies flat. Malathion or Spectracide usually is effective for spraying them. However, effective spraying of a big tree is usually not a do-it-yourself project, and if you don't spray, there is a good chance that predators will move in and reduce the aphid population before it does extensive damage. Q: I've been told I should wrap the trunk of a maple tree I planted this spring. Why? A: It will retard evaporation of moisture from the bark, protect the bark from the sun and prevent sun scald. It also prevents borers from attacking the tree. Burlap is a good material to use, and special paper is available at most nurseries and garden centers. Q: Just what do nematodes do to plants that causes them to be harmful? A: Nematodes, tiny eel-like worms that attach themselves to the roots, feed on the roots and interfere with the tissues that carry nutrients and water to the stems and branches. They also create openings in the roots that permit disease organisms to enter the plants.