The predatory bug Orius laevigatus belongs to the family Anthocoridae, the order Hemiptera. It is a small insect, which has a piercing-sucking mouth apparatus and two pair of wings. The representatives of the genus Orius are polyphages and able to eat pollen and flower sap, different species of thrips, aphids, whiteflies, mites and moth eggs. Various species of Orius are known as effective consumers of the western flower thrips. In nature they inhabit regions of moderate climate. The species Orius laevigatus lives in the basin of Mediterranean sea from the Atlantic region of Western Europe to the Eastern part of Mediterranean sea including Israel.
Orius has 7 stages of ontogenesis: an egg, 5 larva (nymph) stages and an adult individual. The female lays eggs in plant tissue on the underside of a leaf. The egg is almost entirely inserted in the tissue of a plant. Therefore it is possible to see only the top part of it on the surface of the leaf. After the laying the egg is pallid, then it becomes lactescent-white. Its size is 0.4×0.13 mm. During life activity the female is able to lay 120–150 eggs (approximately 1–3 eggs per day). The most number of the eggs is laid in the first 2 weeks of life. The eggs are laid separately (individually), and approximately in 4 days at a temperature of 25°C the first larvae emerge. They are nitidious and pallid. After several hours the larva assumes a yellowish tint remaining during the 2nd and the 3rd stages of the larva. During the 4th and the 5th stages of nymph or larva development the coloration becomes dark-brown and larva bodies become similar to the shapes of adult bugs. The nymphs and the imago have flat bodies that allow them to penetrate in flower buds between petals. The adult is brown-black with grey spots. Its body size is 2.5–3 mm. The sex of individuals can be distinguished by means of genitals and the presence of an ovipositor at the female. Soon after emergence the adult begins to mate and in 3–5 days (dependently on temperature) the female lays the first egg. Development period for various species of Orius depends on temperature, food (proper quantity and quality) and to a lesser degree on the type of a crop. The availability of pollen improves feeding and development. The time of Orius development from an egg to an adult takes about 16–18 days at 25°C. The life span of the adult is 3–4 weeks herewith the male has the shorter period of life than the female has. Sex ratio is 1:1. During all the active stages of life the predator has possibility to hunt and kill preys puncturing them and sucking out liquid from their bodies. The female is able to kill 60–70 thrips per day and the larva can eat 25–30 ones per day. The excess of food doesn't hinder the bug to kill more preys than it needs. The adult Orius has well ability to move (overfly) that contributes very much to search new preys.
Since 1991 several species of Orius are commercially used in the world for the control of different thrips species, especially it concerns the western flower thrips. The bug can be applied on many vegetable crops (the pepper, the cucumber, the eggplant) and ornamental-flower crops (the rose, the gerbera, the chrysanthemum) in the conditions of glass-covered ground. The preventive application of the entomophage begins under the appearance of the first flowers of a crop. The rate of application is 1–2 individuals per 1 m2. The high density of pest population requires local invasions in focuses in amounts of 5–10 individuals per 1 m2.
- application on many crops;
- pollen can be an alternative source of food;
- can be used in the focuses of pest populations;
- ability to kill more preys than it needs for feeding;
- possibility to feed on other insects;
- important component in complex IPM-programs directed against thrips (Amblyseius cucumeris, Hypoaspis miles, Amblyseius degenerans).
Transportation and storage
- keep out of direct sunlight;
- transport and store at 5–10°C;
- apply within 18 hours since the moment of reception.