The caterpillar is a wormlike insect that metamorphoses into one of the many varieties of butterfly or moth that are found in nature. Because a caterpillar is basically a youthful version of a larger insect, it can look like a number of other insects during its immature phase when it is going through a number of changes.
Sawfly larvae look very much like caterpillars, and they can be found eating the same types of green plants that caterpillars feast on during their growing stage. The most distinguishable difference between caterpillars and sawfly larvae is that the sawfly larvae tend to have more small legs in between their jointed legs. Their heads are also more noticeable than those of caterpillars, which usually blend into the rest of the body. Sawfly larvae tend to have smaller heads that are a different color from the rest of the body.
Dermestid Beetle Larvae
Dermestid beetle larvae are typically brown, fuzzy and fat. They look very similar to the caterpillar when the caterpillar is close to the point where it's going to build its cocoon and has grown in mass. The dermestid beetle larvae will grow to look like a typical beetle; however it will go through about five immature stages, including shedding its skin just as caterpillars do. Dermestid beetle larvae are also different from caterpillars in that they feed more on pollen and nectar instead of the green leaves of plants.
Centipedes are insects that have long, slender, segmented bodies; they are usually brown in color. Many varieties of the caterpillar share these physical properties. Centipedes typically have about 15 pairs of legs. Centipedes do not eat vegetation as caterpillars do. The centipede feasts on insects only. Also, unlike the caterpillar, centipedes often survive indoors in dark, damp areas such as a basement.
A grub is a form of a beetle in its infancy stage. During the time it is a grub, it lives in soil eating the roots of plants. You will see it come to the surface occasionally. It looks very much like a caterpillar in its growing stage when it is short, fat and segmented. The difference between the two is that grubs are often whiter in color though they can look brown when they are first emerging from the soil.