Tripide in fase di fioritura
Thrips major Uzel
Rubus thrips
This widely distributed species is associated with the flowers of many plants, but especially Rosaceae, and is yet another thrips implicated in the malformation of strawberry fruits. Adults have 7-segmented antennae and are mainly brown, but the colour of the body and wings in this species is rather variable. Adult females are active mainly from early spring to early autumn; nymphs are present from May to September.
Thrips meridionalis Priesner
Peach thrips
This species occurs on the flowers of Rosaceae, particularly apple, pear, almond, apricot, cherry, nectarine, peach and plum. Also reported as a pest of grapevine, e.g. in France. Widely distributed in the warmer parts of mainland Europe.
DESCRIPTION
Adult female: body brownish black; antennae 8-segmented, including a 2-segmented style. Adult male: similar to female, but paler in colour.
LIFE HISTORY
In southern Europe there are typically three overlapping generations annually. Adults overwinter in the shelter of dead leaves and become active from mid-February onwards. They invade early-flowering hosts, such as almond. Later, the pest migrates to other hosts as these reach the flowering stage. Eggs are laid in the flowers over a period of several weeks, development from egg to adult taking about a month. Eggs of later generations are laid in leaves or fruits. Adults of the final generation mate in the autumn and the impregnated females then take up their winter quarters.
DAMAGE
Particularly on nectarine (and, to a lesser extent, on peach), attacks on blossoms can reduce fruit set (owing to damage to the stamens), or can result in the development of necrotic patches on fruitlets (following damage to the ovaries). Necrosis can also result from direct attacks on very young fruitlets; these damaged areas enlarge as the fruitlets grow and may then split open, allowing gum to exude from the cracks. Damaged fruitlets may also become distorted, or they may wither and die without reaching maturity. Further, eggs laid in the skins of fruit are unwelcome contaminants.