Basil, like all garden plants, are prime targets for a variety of garden pests. Though many critters feed on basil, there are three that stand out as being the most invasive.
Three Most Common Basil Pests
Aphids feed on and destroy a variety of plants including basil. They are tiny, white, soft-bodied bugs that will feed on new growth causing malformation of the leaves. They can be controlled through insecticidal soaps as long as they are used in the evenings to prevent damage to the leaves.
It is usually no secret if your garden is infested with Japanese Beetles. These dime-size, metallic looking bugs do not scare easily so you will likely witness them chewing the tell-tale ragged holes in your basil plants. You can get rid of Japanese beetles by hand picking them off each plant and crushing them. They will also die if dropped in soapy water.
If this is a yearly issue, the best method of control is to deal with them during the ten months out of the year that they begin as grubs.
Slugs will crawl up the stems of your basil and feed on the leaves leaving ragged holes. A simple method to control slugs is to sprinkle diatomite, a naturally occurring sedimentary rock that can be crushed into a powder, around the base of your basil plants. The diatomite powder is coarse causing fissures in the slug when it attempts to crawl across it. The physic-sorptive properties of the diatomite absorb the lipids from the slug causing it to dehydrate.
Additional Basil Pests
As if the three mentioned were not a sufficient nuisance, the list of basil pests as actually quite extensive and includes varieties of: beet armyworm, celery leafminer, Chinese rose beetle, eriophyid mite, garden flea hopper, grass bagworm, hemispherical scale, lantana hispid, leafhopper, palestriped flea beetle, pinkwinged grasshopper, root-knot nematode, southern green stink bug, spittlebug, thrips, and whitefly.