Lady Beetles (Coccinellidae)
COCCINELLIDAE – MORPHOLOGY, ECOLOGY, AND GLOBAL DISTRIBUTION
Lady beetles (Coccinellidae; from Latin coccineus “scarlet,” referring to their characteristic red coloration) are a cosmopolitan family of Coleoptera comprising over 6,000 described species worldwide. In Europe, approximately 300 species are recorded, with around 80 species occurring in the Czech Republic. Adults measure 1–10 mm in length and display a strongly convex, hemispherical or oval body, often brightly colored with red, orange, or yellow elytra adorned with black spots, stripes, or maculae as aposematic warning signals. The head is typically black with prominent eyes and short antennae; legs are short, adapted for crawling on leaves. Both adults and larvae are predatory, primarily feeding on aphids, mites, and occasionally fungi. The most emblematic species is the seven-spot lady beetle (Coccinella septempunctata), recognized by its seven black spots on a red background. Wikipedia
DISTRIBUTION AND SPECIES IN THE CZECH REPUBLIC
In the Czech Republic, the seven-spot lady beetle (Coccinella septempunctata, 5–9 mm) dominates gardens and meadows. Other notable species include the twelve-spot lady beetle (Coccinella duodecimpunctata) and the two-spot lady beetle (Adalia bipunctata). The invasive harlequin ladybird (Harmonia axyridis), introduced in the early 2000s, is rapidly spreading and poses competitive pressure on native species. Globally, Coccinellidae inhabit temperate, tropical, and subtropical zones, occupying diverse terrestrial habitats such as grasslands, forests, agricultural fields, and urban gardens. Rare endemic species are vulnerable and listed on regional Red Lists.
ECOLOGY AND HABITAT PREFERENCES
Lady beetles occupy herbaceous vegetation, forest edges, orchards, and croplands. Both adults and larvae actively hunt aphids and other pest arthropods, providing critical biological control in agroecosystems. They are primarily active during warm periods from spring through autumn. Aggregations occur during overwintering under bark or in man-made structures. Individual lady beetles consume hundreds of aphids over their lifespan. Larvae are elongate, gray with orange tubercles, highly mobile, and capable of flight as adults for dispersal and pollen foraging.
LARVAL PREDATORY BIOLOGY
Coccinellid larvae are elongate, tapered posteriorly, gray-black with yellow maculae, and reach up to 10 mm in length. They pass through 4–5 instars and consume up to 800 aphids during development. Larvae also feed on eggs and larvae of other pest species, and display cannibalistic behavior, consuming conspecific eggs when prey is scarce. Pupation occurs on plant surfaces, with adults emerging after 1–2 weeks.
REPRODUCTION AND LIFE CYCLE
Females deposit yellow to orange eggs in clusters of 10–50 on the undersides of aphid-infested leaves from April to August. Eggs hatch after 3–7 days depending on temperature. Larval development spans 10–15 days, followed by pupation. The complete life cycle lasts 4–7 weeks, allowing for 1–2 generations per year in most species. Adults overwinter and reproduce in the following season, living for several months.
ECOLOGICAL AND ECONOMIC IMPORTANCE
Lady beetles are keystone predators in terrestrial ecosystems, serving as natural regulators of aphids, mites, and other herbivorous arthropods. They reduce the need for chemical pesticides in horticulture and agriculture, enhancing sustainable crop management. Conservation strategies include promoting habitat heterogeneity, maintaining flowering field margins, and monitoring invasive species such as Harmonia axyridis. Globally, Coccinellidae play a crucial role in both natural and agroecosystems, with diversity hotspots in temperate Eurasia, tropical Asia, and the Americas.
GLOBAL CONTEXT
Coccinellidae exhibit worldwide distribution, inhabiting all continents except Antarctica. Their success is associated with morphological adaptations for predation, aposematic coloration, and ability to exploit diverse prey and habitats. Many species exhibit pronounced polymorphism, sexual dimorphism, and adaptive life-history strategies, including diapause for overwintering. Invasive species have altered local community dynamics, demonstrating the ecological sensitivity of native Coccinellidae populations to anthropogenic pressures.