''Novius cardinalis'' (common names vedalia beetle or cardinal ladybird) is a species of ladybird beetle native to

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

. It was formerly placed in the genus ''Vedalia'', then renamed to ''Rodolia'', but that genus was synonymized under the genus '' Novius'' in 2020.Pang, H., Tang, X.-F., Booth, R.G., Vandenberg, N., Forrester, J., Mchugh, J., & Ślipiński, A. (2020) Revision of the Australian Coccinellidae (Coleoptera). Genus ''Novius'' Mulsant of Tribe Noviini. ''Annales Zoologici'' 70 (1):1–24. https://doi.org/10.3161/00034541ANZ2020.70.1.001 The "vedalia beetle" came to public attention as an effective

biological control Biological control or biocontrol is a method of controlling pests, whether pest animals such as insects and mites, weeds, or pathogens affecting animals or plants by using other organisms. It relies on predation, parasitism, herbivory, or o ...

agent against cottony cushion scale, a serious pest of

citrus ''Citrus'' is a genus of flowering trees and shrubs in the family Rutaceae. Plants in the genus produce citrus fruits, including important crops such as oranges, mandarins, lemons, grapefruits, pomelos, and limes. ''Citrus'' is nativ ...

plantations.

Description

The adult has a domed oval body, flattened underneath, long, covered with dense, short hairs. Its coloration is an irregular and variable pattern of red and black, sometimes with more red, sometimes with more black. The head, the back of the prothorax, and the scutellum are all black. The species feeds exclusively on the cottony cushion scale, ''Icerya purchasi'', which feeds on trees including acacia, citrus, magnolia, olive, and rose. The beetle's young larvae eat the scale insect's eggs; older larvae and adults eat all lifecycle stages of the scale insect.

Life-cycle

The eggs are red. They are laid underneath the protective scale of scale insects, or directly on the scale insect's egg sacs. Each female lays between 150 and 190 eggs. First instar

larva A larva (; : larvae ) is a distinct juvenile form many animals undergo before metamorphosis into their next life stage. Animals with indirect development such as insects, some arachnids, amphibians, or cnidarians typically have a larval phase ...

e have reddish bodies and legs. Older larvae have black tubercles on both thorax and abdomen, and black legs. There are four instars; fourth instar larvae grow to around in length; they attach themselves to a twig or leaf when they are ready to pupate. The

pupa A pupa (; : pupae) is the life stage of some insects undergoing transformation between immature and mature stages. Insects that go through a pupal stage are holometabolous: they go through four distinct stages in their life cycle, the stages th ...

is long; its case is off-white. Breeding is rapid, with as many as 12 complete generations in a year in hot, dry regions, or about 8 generations in cooler places. However, females stop laying eggs if the temperature rises above .

As a biological control agent

An outbreak of cottony cushion scale in

California California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...

led to the importation of 514 "vedalia beetles" from Australia in 1888 as a

agent to protect plantations of

trees. The effort was successful, becoming a "spectacular" instance of biological control. This was followed by regular commercial use for that purpose.

Distribution

''Novius cardinalis'' is native to Australia. It has been introduced in citrus-growing regions of Europe and the United States.

References

External links

{{Taxonbar, from=Q2235176 Beetles of Australia Coccinellidae Beetles of New Zealand Beetles described in 1850 Taxa named by Étienne Mulsant