Adalia bipunctata
The twin spot ladybird (Adalia bipunctata) is an active predator of aphids from the order beetles (Coleoptera), the family ladybird (Coccinellidae). This species is widely spread in the wild nature of Europe. As an agent of biological control it is applied in many countries of the world. The entomophage is used in covered ground for the suppression of different species of aphids (cotton aphid, peach potato aphid, black bean aphid, potato aphid).
The adult predator is 5–8 mm in length, bright-red. Its pronotum is black with a distinctive pattern. The pattern of a male and the pattern of a female are not similar (it is possible black coloration of a beetle body). There are 4 ages of larvae. The first age larva is grey or black. The third and the forth have yellow and orange spots. The pupa is cylindrical, orange with black points and spots. The egg is yellow-orange, its size is 0.4 mm. The female lays eggs in groups of 10–40 in aphid colonies on a leaf underside. The duration of oviposition is about 30 days. The fertility of the female during her life cycle is to 500 eggs. Preimaginal development at a temperature of 25°C is about 19 days. The average life span of an adult individual is 56 days. Sex ratio is about 1:1.
The larvae and the adults are predators. The larvae of older ages move actively on the whole plant for the search of food and also migrate to other plants. The adult individuals keep not far from preys where they mate and lay the eggs. The imago kills an average of 30 aphids per day herewith the feeding of the female is more intensive. A larva during the period of development eradicates to 250–270 and the adult individual eats more than 1300 aphids. The deficiency of food can cause cannibalism.
Application
Adalia bipunctata is widely applied as a biological agent against aphids for protection of vegetables (cucumber, sweet pepper, eggplant), strawberry, and some other crops in covered ground. The larvae (besides the first age ones) and adult beetles are applied. The species is most effective in complex with such entomophages as Aphidoletes aphidimyza, Aphidius colemani, Aphidius ervi or Aphelinus abdominalis. Application in complex system is based on the peculiar properties of Adalia bipunctata biology. The species is characterized by intensive feeding process but when the colony of a pest becomes small the entomophage leaves it and searches another colony (more numerous). Herewith it is possible that inconsiderable number of the pest remains and the renewing of pest population occurs. Dependently on pest population density the release of the entomophage is fulfilled in amounts of 10–50 individuals per 1 m2. It is recommended to release the predator in the places of pest concentration in the morning or in the evening (the cool time of a day). If necessary the additional releases of the biological agent are accomplished (it is possible imago migration from a greenhouse).
It is not recommended the application of the biological agent for preventive measures because of the cannibalism of young ages and possible migration of imago.
The optimal conditions of Adalia bipunctata development are: a temperature of 24–28°C, a relative air humidity of 70–80%, a day light duration of 18 hours. The adults are most active under sufficient sun illumination.
Advantages
- high feeding intensiveness;
- high mobility in the process of food searching;
- large number of pests as a food source;
- the simplicity of the determination of entomophage level activity in the process of monitoring.
Storage and transportation
- keep out of direct sunlight;
- ransport and store at a temperature of 10–15°C;
- use within 18 hours since the moment of reception.
