Chrysoperla carnea

The aphis lion (Chrysoperla carnea) is an enough big insect which belongs to the family Chrysopidae, the order Neuroptera. Different species of aphis lions (more than 1350) occur everywhere. The species Chrysoperla carnea has the widest spreading. This insect inhabits Europe, Asia and America, where it is actively used against pests in the system of agricultural crop defense.

The adult individual is green with a brownish-red strip and a yellow strip on the spinal part of a body from a head to an abdomen. The size of the imago body is 12–20 mm in length. There is a pair of long antennae on the frontal part of the head. The eyes are light-golden. The wings are equal developed, transparent. Their spread is 23–30 mm. The legs are pale-green with brown tarsi (paws). The adult is able to move, mainly in the evening and at night. The imago feed on the sweet excretions of insects, flower nectar and pollen.

Chrysoperla carnea Chrysoperla carnea Chrysoperla carnea Chrysoperla carnea

The female of the entomophage lays solitary green eggs setting them on long strands attached to the leaves or other parts of plants. Fertility is between 100 and 900 eggs. The larva is an active predator consuming aphids, mites, coccids, eggs of many insect species. But it mostly prefers aphids. Moreover, it is inherent cannibalism to the aphis lion. The larva feeds intensively, molts twice, after that pupates in an oval white cocoon. The adult emerges from the cocoon in 10–14 days. During growth the size of the larva changes from 1 mm to 6–8 mm. The coloration of the larva is grey or brown. After emergence the larva begins to search preys by means of the sensitive cells of palpuses (feelers) and jaws. Its gluttony depends on the kind of food and availability. Within the stage of development (the duration of larva stage is 2–3 weeks) one larva kills 200–300 eggs or aphids. During the search of food it is able to exist without nutrition about 24 hours. The female is twice as more gluttonous than the male. All the stages of the entomophage (an egg, a larva, a pupa and an imago) develop in enough a wide range of temperature (20–30°C) and relative humidity (50–80%). In nature it reproduces 2–3 generations per year.

Application

Chrysoperla carnea can be introduced in the systems of the integrated defense of different vegetable crops, fruit and flower-ornamental plants against various aphids. Additionally it is able to feed on thrips, red spider mites, whiteflies, small caterpillars, eggs of moths and mealy bugs. The effectiveness of the entomophage depends on the initial number of pest population. It especially concerns different species of aphids. Therefore it is recommended to release this biological agent in situations when the density of pest population is average or low. The aphis lion is applied as a part of IPM (integrated pest management) program against aphids together with Aphidius colemani, Aphidius ervi, Aphelinus abdominalis and Aphidoletes aphidimisza (dependently on species of the pest). Crysoperla carnea is ideally suitable for the elimination of the localized focuses of aphid populations. That is why it can be used as an alternative of local insecticide applications.

One of the most specific entomophage properties is the tendency of adults to migrate after emergence from the cocoon. Therefore it is difficult to constitute the stable population of the biological agent in a greenhouse.

In the conditions of glass-covered ground the releases of the predator are realized when the first colonies of aphids appear. The best effect is observed under the application of the 2nd and the 3rd larvae ages. In dependence on a crop and the number of pests the ratio predator-prey varies from 1:5 to 1:50. Invasions are realized in amount of 5 individuals per 1 m2, 2–4 times per month. If the density of pest population is large the rate of application per area unit is increased. Owing to the resistance of the entomophage to unstable hydrothermal conditions the predator can be successfully applied in outdoor planting on many crops (the intensive life activity of the entomophage is observed at a temperature of 12–35°C). Chrysoperla carnea possesses a relatively high resistance to the influence of pesticides that allows it to be used in integrated pest management together with selective chemicals.

Advantages

  • application on many crops (vegetables and ornamental) in greenhouses and outdoor planting;
  • entomophage activity doesn't depend on temperature and relative air humidity (a wide range of hydrothermal conditions);
  • high resistance to the influence of synthetic pesticides;
  • the high effectiveness of larvae in the focuses of pest population because of its high aggression;
  • polyphagy allows the biological agent to eat alternative food (thrips, mites, caterpillars, eggs of pests).

Transportation and storage

  • transport and store in darkness at a temperature of 5–10°C;
  • don't expose to direct sunlight;
  • keep a pack in horizontal position;
  • apply within 18 hours since the moment of reception.