These insects were given their name in the Middle Ages when they were dedicated to "Our Lady" in gratitude for their ridding crops of harmful insect pests.
Some people find it a nuisance when lady beetles come into their houses in large numbers to hibernate. The best course of action is to sweep or vacuum them up gently, and seal cracks to prevent them from gaining entry (Klaas 1998).
Ladybugs are more properly known as lady beetles, because "bug" applies most accurately only to insects in the order Hemiptera.
Non-native lady beetle species have been introduced into North America for additional aphid control, and there is some concern that these species are displacing native species like the Two-Spot. (Marshall 2000)
US Federal List: no special status
CITES: no special status
Can be a nuisance if large numbers get inside houses (Klaas 1998, Fleming 2000).
This species helps control populations of aphids that are agricultural and horticultural pests.
Lady beetles feed on aphids and other small insects, insect eggs, and mites.
Native to North America (Marshall 2000).
Biogeographic Regions: nearctic (Native )
Lady beetles will live in nearly any vegetation, as long as there are aphids or other small insects to eat.
Terrestrial Biomes: savanna or grassland ; chaparral ; forest
Adult two-spotted lady beetles are 4-5mm long, and ovoid in shape. The head and thorax is black with yellow markings. Their undersides are black to reddish-brown; Their elytra (wing covers) are orange with one black spot on each side. The larvae are elongate, with soft bodies, and are black with yellow and white spots (they look a little like tiny alligators) (Marshall 2000, Milne & Milne 2000).
Range mass: 0 to 0 kg.
Other Physical Features: ectothermic ; bilateral symmetry
Females deposit bright yellow eggs on the underside of leaves and other locations near potential food sources for the larvae. Pupae are black with yellow dots and are found hanging from leaf surfaces. Adults in the North live through the winter; there can be more than one generation in a year.
Adalia bipunctata, the two-spot ladybird, two-spotted ladybug or two-spotted lady beetle, is a carnivorous[1] beetle of the family Coccinellidae that is found throughout the holarctic region. It is very common in western and central Europe. It is also native to North America but it has heavily declined in many states and provinces. It is commonly introduced and imported as a biological control agent.
The two-spotted ladybird was one of the many species originally described by Carl Linnaeus in his 1758 10th edition of Systema Naturae; its original name was Coccinella bipunctata.[2] Its specific name is from the Latin bi- "two", and punctata "spotted".[3]
Adalia bipunctata is a small Coccinellid that can feature any one of a large selection of red and black forms. Some forms are similar to Mulsantina picta, but the two white spots on the head of Adalia (in contrast with a large white region or more than two spots) readily separate it. Additionally Adalia is entirely black on the ventral surface with black legs, which helps rule out any other options.
The two-spotted ladybird is highly variable in many parts of its native range. The most familiar form, form typica with two black spots on a red base, is common throughout. A melanistic form that is black with four or six red spots is uncommon, but not rare, while the truly melanistic form purpurea is exceedingly rare. In North America the species shows the most variation, with several forms that do not occur elsewhere including a spotless form, a four-banded form, a nine to twelve spotted form, and a "cross-hatched" form. In addition, there are intermediate forms such as form annulata, but they occur rarely.[4]
Two-spotted lady beetles feed on aphids and other small insects.[1][4][5] However, the sterile soldiers within colonies of aphids such as the gall-forming Pemphigus spyrothecae, can attempt to protect the aphid colony by fighting this species.
The two-spotted lady beetle's life cycle starts with eggs that are usually laid in clutches.[1][5] The larva hatches from the egg by biting a hole in it. The larva looks very different from an adult; it has an elongated, grey, soft body with six legs but no wings. They are cannibalistic. A larva goes through four larval stages: by eating it grows and at some point it sheds its old skin and appears in a new one in which it can grow more. The last larval stage is approximately the size of an adult beetle. Once it has eaten enough, the larva attaches itself to a substrate and moults into a pupa. Inside the pupa, the adult develops. Finally the adult ecloses from the pupa.
Life cycle of Adalia bipunctata. Illustration from Insects, Their Way and Means of Living by R. E. Snodgrass
_mating.JPG)
Spotted lady beetles mating
Larva
Pupa
The adult beetle
.jpg)
Newborns
In some populations, the majority of the beetles are female. In these populations, 80-90% of the offspring are female. The cause of this anomaly is the presence of symbiotic bacteria living within the gametic cells of the female lady beetles. The bacterium is too large to live in the male gametes (sperm), so the bacterium can be transmitted to the next generation only through female gametes. When it ends up in a male, it will die when the male dies. Therefore, it kills most of the male embryos in the newly laid eggs. These dead embryos then serve as food for their sisters when they emerge from their eggs. This trait is associated with a variety of bacteria (Wolbachia,[6] Rickettsia,[7] and Spiroplasma[8]) which are present in between 0 and 20% of females, depending on locality.
The two-spot ladybird also carries a sexually transmitted infection in Central and Eastern Europe. The infection is an ectoparasitic mite Coccipolipus hippodamiae that transfers between male and female (and female and male) during copulation.[9] The infection sterilizes female two-spot ladybirds, and at some points of the year, up to 90% of adult two spots become infected.[10]
A. bipunctata is used as a localised biological control agent against aphids in, for example, greenhouses.. The two-spotted lady beetle was introduced into Australia specifically as a biological control agent.[11]
Adalia bipunctata, the two-spot ladybird, two-spotted ladybug or two-spotted lady beetle, is a carnivorous beetle of the family Coccinellidae that is found throughout the holarctic region. It is very common in western and central Europe. It is also native to North America but it has heavily declined in many states and provinces. It is commonly introduced and imported as a biological control agent.
