Calvia quatuordecimguttata, the cream-spotted lady beetle, has a oval shaped body, and is 3.5 to 5.5 mm long. These beetles are polymorphic, in this case meaning that despite being the same species, they can have different colors and patterns on their elytra, which cover their wings. In North America, C. quatuordecimguttata has three different patterns: black with 14 white spots, black with 2 or 4 red spots, and orange with 12 black spots. In other areas, C. quatuordecimguttata is maroon-brown in color. (Eaton and Kaufman, 2007; Gordon, 1985; Lamana and Miller, 1995)
Calvia quatuordecimguttata is native to northern North America, northern Europe, and western and central Asia. In North America, this range extends from northern California to Alaska on the west coast and from New Jersey to northern Canada on the east coast. Calvia quatuordecimguttata is the only species of the genus Calvia that is found in North American. (Gordon, 1985; Lamana and Miller, 1995)
Calvia quatuordecimguttata is found in forests of deciduous trees and shrubs. This species also lives amongst flowering plants that are present in dry grassland. It can also be found on agricultural land, living on crops. (Gordon, 1985; Taylor and Francis, 1966)
Calvia quatuordecimguttata goes through complete metamorphosis, with a life cycle consisting of egg, larva, pupa, and adult stages. Eggs are laid in the early spring by adults that were in hiding over the winter (overwintering). After larvae emerge and then pupate, adults live for a few weeks in the summer until the weather cools, when the adults that are still alive overwinter. Adults of C. quatuordecimguttata cannot mate and reproduce until after emerging in the spring. Development of C. quatuordecimguttata is effected by temperature, with beetles that develop at lower temperatures reaching a greater size. The time of development from egg to adult also depends on temperature, taking about 14 days at 30 degrees Celsius, while taking up to 115 days at lower temperatures (10 degrees Celsius). (Gordon, 1985; Kalushkov and Hodek, 2001; Lamana and Miller, 1995; Webberley, et al., 2004)
There is little to no information available on this topic for Calvia quatuordecimguttata. It is known that both male and female cream-spotted lady beetles can have multiple mates. (Eaton and Kaufman, 2007)
There is little to no information available on this topic for Calvia quatuordecimguttata.
After laying eggs, adults do not provide any more care for their offspring. Additionally, the eggs of C. quatuordecimguttata are coated with a chemical that protects the eggs from attacks by Harmonia axyridis, another species of lady beetle. (Ware, et al., 2008)
Eggs of C. quatuordecimguttata are laid in the spring, as early as March. The time of development from egg to adult depends on temperature, taking about 14 days at warmer temperatures, while taking up to 115 days at lower temperatures. Adults live for several more weeks or months through the summer, until temperatures cool in the fall and adults overwinter, emerging again the following spring. (Gordon, 1985; Lamana and Miller, 1995)
There is little information available on this topic for Calvia quatuordecimguttata. The cream-spotted lady beetle can fly, and is mainly a solitary species.
Related lady beetle species use sight and detect chemicals to find prey and mates, and this is likely true for C. quatuordecimguttata as well.
Calvia quatuordecimguttata are insectivores. They eat psyllids and aphids, which are small insects that feed on plants, often crops. Feeding on psyllids seems to cause faster larval development, especially Cacopsylla mali. Six aphid species have been identified as food for C. quatuordecimguttata: Chaitophorus tremulae, Cavariella konoi, Aphis farinosa, Eucalipterus tiliae, Euceraphis betulae, and Macrosiphoniella artemisiae. (Gordon, 1985; Kalushkov and Hodek, 2001)
Other species of lady beetle often eat the eggs of Calvia quatuordecimguttata. Harmonia axyridis is an invasive lady beetle that is known to eat the eggs of many other lady beetles. Calvia quatuordecimguttata is well protected against the attack of Harmonia axyridis due to a substance on the outer surface of its eggs. There are also patches of a red substance that coat the eggs, which is believed to be a type of acid, which would also protect the eggs from predator attacks. Cannibalism also occurs in this species, with adults and older larvae sometimes eating eggs and larvae of its own species. Like other lady beetles (Coccinellidae), C. quatuordecimguttata can likely bleed toxic chemicals out of its joints when it is threatened by a predator. The different colors and elytral patterns of this species are a warning signal to predators. Predators know that brightly colored beetles are often poisonous, so the bright colors of C. quatuordecimguttata make predators less likely to eat it. (Gordon, 1985; Ware, et al., 2008)
Calvia quatuordecimguttata is a predator of many species of aphids and psyllids. It can be prey to other species of lady beetle. Coccipolipus hippodamiae is a parasitic mite that lives under the elytra of Calvia quatuordecimguttata. When males and females mate, the mites can move from one beetle to another. (Kalushkov and Hodek, 2001; Webberley, et al., 2004)
There are no known negative affects of Calvia quatuordecimguttata on humans.
Aphids and psyllids, which eat plants, can often do damage to many crops that people grow. Since Calvia quatuordecimguttata eats these insects, it can control the size of these insect populations and keep crops from being damaged. (Kalushkov and Hodek, 2001; Semyanov, 1996; Kalushkov and Hodek, 2001; Semyanov, 1996)
Calvia quatuordecimguttata is not an endangered species.
Deeana Ijaz (author), University of Michigan Biological Station, Angela Miner (editor), Animal Diversity Web Staff.
Eaton, E., K. Kaufman. 2007. Kaufman field guide to insects. Boston, Massachusettes: Houghton Mifflin Harcourt.
Kalushkov, P., I. Hodek. 2001. New essential aphid prey for Anatis ocellata and Calvia quatuordecimguttata. Biocontrol Science and Technology, 11: 35-39.
Lamana, M., J. Miller. 1995. Temperature-Dependent Development in a Polymorphic Lady Beetle, Calvia quatuordecimguttata (Coleoptera: Coccinellidae). Annals of the Entomological Society of America, 88/6: 785-790.
Semyanov, V. 1996. Lady beetles (Coleoptera, Coccinellidae) of Leningrad region orchards (fauna, biology and their role in pest population dynamics). IOBC/WPRS and ISHS International Conference on Integrated Fruit Production, 422: 208-211.
Taylor, , Francis. 1966. The pattern of animal communities. Great Britain: Menthuen and Co Ltd, II New Fetter Lane, London EC4.
Ware, R., F. Ramon-Portugal, A. Magro, C. Duncamp, J. Hemptinne, M. Majerus. 2008. Chemical protection of Calvia quatuordecimguttata eggs against intraguild predation by the invasive Harmonia axyridis. Biological Control, 53: 189-200.
Webberley, K., G. Hurst, R. Husband, J. Schulenburg, J. Sloggett, V. Isham, J. Buszko, M. Majerus. 2004. Host reproduction and a sexually transmitted disease: Causes and consequences of Coccipolipus hippodamiae distribution on coccinellid beetles. Journal of Animal Ecology, 73/1: 1-10.