Many of us can recall a time seeing a ladybug on the ground, picking it up, just to watch it fly away. Although we can all relate to such an experience, we may have not all realized the significance ladybugs have on the environment. There are many species in the ladybug family, Coccinellidae. One specific ladybug is the Coccinella septempunctata Linnaeus, also known as the seven spotted lady beetle. These Coccinella septempunctata have oval shaped bodies, containing wings. Being brightly colored, C. septempunctata also have chewing mandibles to inhibit their predator behavior. C. septempunctata prey and feed primarily on aphids. C. septempunctata contribute to the environment by ridding it of overpopulated pests. Although C. septempunctata help to rid the environment of pests, it has pests of its own. The most common parasitoid of C. septempuntata is the Perilitus coccinellae, braconid wasp. C. septempunctata, also, have many defense mechanisms, interesting brooding behavior and habitats.

Defense Mechanisms

Accounting for their lack of size, C. septempunctata are brightly colored. These bright colors repel predators in fear that they are poisonous. C. septempunctata also have innate defense mechanisms. A C. septempunctata is capable of secreting a noxious fluid from its tibio-femoral articulations, or leg joints. This noxious fluid, hemolymph, is the C. septempunctata’s most efficient way to repel predators. This yellow hemolymph has such a repulsive smell that it causes predators not to approach the species.

Brooding Mechanism

Larger than males, adult female C. septempunctata lay their eggs in clusters. Eggs are most commonly laid on plants in the vicinity of aphids. The eggs then progress to the larvae stage. C. septempunctata larvae have a spotted, spiked, yellow and blue alligator appearance. Even at the larvae stage C. septempunctata are predators.  Although the larvae have an intimidating appearance, they are harmless.  After feeding on insects for several weeks, the larvae will pupate on a leaf. The new adult C. septempunctata will remain in the birthing location until pests become scarce.  Through the course of a year, C. septempunctata will go through several generations. Winter months slow the reproduction process, due to adult hibernation. 

Ecology

The C. septempunctata is native to Europe, and was introduced to Florida to help manage the population of aphids. This species typically resides in areas that are high in aphids because that is, after all, the main food supply of C. septempunctata.

Biological Control

Although minute in appearance, C. septempunctata are, interestingly, very useful in biological control. C. septempunctata are beneficial because they are predators of pests. Many gardeners spray pesticide on the eggs and larvae of the C. septempunctata thinking that it is a pest, however, ridding the garden of C. septempunctata only causes more pests to arise. While C. septempunctata control the population of many pests, they are also controlling the spread of disease.

Manipulative, augmentative, and inoculative biological control is being used on C. septempunctata to preserve and establish populations of C. septempunctata. Making conditions as favorable as possible for C. septempunctata, manipulative biological control is used. Augmentative biological control is also used to preserve C. septempunctata by purchasing C. septempunctata from commercial producers. C. septempunctata are purchased to augment the already present C. septempunctata. Lastly, placing C. septempunctata in areas that do not already contain C. semptempunctata is used to establish a population. This process is referred to as inoculative biological control.  

Bessin, R. (2007). Ladybugs. Unpublished manuscript, Department of Entomology, University of Kentucky, Kentucky. Retrieved from http://www.ca.uky.edu/entomology/entfacts/ef105.asp

Frank, J. (n.d.). Ladybugs of florida, coleoptera: coccinellidae1. Unpublished manuscript, Department of Agriculture, University of Florida, Gainseville, Florida. Retrieved from http://edis.ifas.ufl.edu/in327