Insecticidal soap is effective, as are products with neem. Fire ants can be especially annoying, and diazinon drenches have been one of several mound treatments used by home gardeners. Organic home remedies for treating ants include drenching a mound with straight vinegar, soapy water or boiling water. Be extremely careful approaching and treating a mound. Baits are effective synthetic treatments, and to many, your best bet.
Mealy bugs appear on stems and buds.
If the infestation is not too severe, dip a cotton swab in rubbing alcohol and scrub the mealies off. You can wash them off your plant with jets of water, pick them off with tweezers, or use an insecticidal soap or pyrethrum spray. But try to avoid even this if you're trying to attract mother butterflies to the garden to lay eggs, which, of course, hatch into caterpillars before their transformation into butterflies. Try Bt for beetles to discourage the June beetle's larvae, those nasty white grubs. Citrus juice improves in quality the longer the fruit is stored on the tree.