Ladybugs are usually generalist and feed on plants, crops, eggs, larva, and other insects; especially aphids in Alaska. Aphids pierce a leaf or stem of a plant and suck out the juice, which leaves a honeydew excretion behind and subsequently ants feed upon the residue. The ants in turn attack predators of aphids to keep up the supply of honeydew. This turns into a three-way predator prey relationship between aphids, ladybugs, and ants.
Therefore, to get rid of a high population of ants and aphids a good idea is to introduce ladybugs that will prey upon the aphids. Ants are not the only predator of ladybeetles, wasps and some moths also prey upon them. An ecosystem can become very complicated in a short amount of time.
Ladybugs have a two-step system of avoiding predators. The first is a reflex-bleed from the tibio-femoral articulations (leg joints). The blood (hemolymph) is a yellow staining repellent having a repulsive smell as well as containing (in some species) various alkaloid toxins (adaline, coccinelline, exochomine, hippodamine, etc.). The second is an aposematic system, where the ladybugs' bright red or orange color warns would be predators that they are toxic and distasteful.
Ladybeetles or ladybugs are oval and range in length from 0.04 inches (1 mm) to 0.4 inches (10 mm), depending upon the species. Females are larger than males. Adults of some species are brightly colored or spotted. They catch large amounts of prey by using physical contact rather than sight or smell, like other insects and chew with their mandibles (lower jaw). Ladybugs also march in straight lines until they find something to eat. They have wings and can migrate hundreds of miles by riding the winds.
When you see a ladybeetle or ladybug remember they are good at getting rid of pesky insects and are good for the yard or garden.