Seven-Spotted Lady Beetle

Coccinella septempunctata
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Although originating from Europe and Asia, the Seven-Spotted lady beetle can be commonly found throughout the United States. From 1951-1971 this species was introduced to reduce aphid populations. Due to their introduction to the United States and their growing population size, the Seven-Spotted ladybug is classified as an invasive species. Their increase in population has had an impact on the native and less common species of ladybugs.

Read on to learn how to identify this lady beetle from other species...

As its common name entails, the Seven-Spotted ladybug can be identified by its seven black spots, three of which are on each wing and one appearing right behind the head. Being introduced for aphid control their diet can be easily guessed, mainly consisting of aphids, with the occasional meal of pollen and even their relatives if food quantities are low. 

The Seven-Spotted ladybug can be found in a variety of habitats where aphids are abundant. This mainly consists of small plants, shrubs, and trees in open fields or marshlands. During the winter the preferred habitat can be open areas with boulders or densely packed grasses that are in areas receiving maximum sunlight.

Read on to learn about the interesting life cycle of this lady beetle... 

Sexually mature male and female lady beetles will go through a courtship prior to reproducing. The male will approach the female and examine her with his antennae feeling her antennae and mouth. Once the eggs are fertilized the female will disperse them around her environment in areas that are safe and resourceful. Eggs are small and round, usually 1mm in size, and are laid in small groups on leaves. Once the eggs have been laid there is no further parental care. 

The Seven-Spotted lady beetle goes through complete metamorphosis passing through the egg, larvae, pupae, and adult stages that look very different. Egg incubation can last 3-5 days before developing into larvae. Once the larvae emerge they feed on their egg and any surrounding infertile eggs. The larval stage lasts for 2-3 weeks, where they will feed and go through multiple stages within the larval stage called instars.

Read on to learn more...

The Seven-Spotted ladybug has four instar stages where it will shift from sucking the liquids of aphids to eating the entire aphid. After the 2-3 weeks in the larval stage the ladybug will stop eating for 24 hours and attach itself to a leaf. Once attached it will go through the pupa stage of development, which can range from 3-12 days depending on temperature. 

After pupation has occurred the adult will emerge with soft and colorless wings that will develop overtime. The adults will emerge from late March to early April and will mate 1-2 weeks after emergence. Three generations of the ladybug can be produced in a year with the second generation emerging in June. Once adults, the life span of Seven-Spotted ladybugs can range from 1-2 years depending on their survival throughout the winter.

Additional Resources: 

Wichita State University

Kids Critter Catalog from the University of Michigan

Citizen Science Projects from The Xerces Society for Invertabrate Conservation

 

Facts About Seven-Spotted Lady Beetle

Live up to 2 years

Native to Europe and Asia

Considered invasive due to abundance and competition with native species