|
Citrus |
Thrips (Scirtothrips aurantii)
|
Pest description:
Minute insect about 1 mm in length with four long narrow fringed wings. Immature stages orange-yellow in colour. Adults very active having the habit of turning the tip of the abdomen upwards. In the adult phase the wings are folded backwards over the body whilst resting.
|
|
Typical Damage:
Thrips feed on citrus fruit and cause unsightly blemishes on the rind. Thrips concentrate under and around the calyx or where the fruit is touched by leaves, twigs or other fruits. Typical blemishes are the rings of shallow russet marks around the stem end of the fruit caused by thrips feeding on very young fruit. In severe infestations the blemishes resembling tear stains may spread irregularly down over the surface of the fruit. Thrips also feed around the navel or blossom end, causing russety rings around that area. Damage to more mature fruit results in smooth browning of the rind. Thrips damage should not be confused with wind damage, which are usually transverse or diagonal scars, with a different texture to thrips blemishes. Thrips damage to tender new citrus shoots and leaves results in distorted and stunted growth. On macadamia the thrips feed on the undersides of young leaves and cause the edges to curl up. On mango blemishes are caused on the rind around the stem end.
|
|
| Aphids (Toxoptera citricidus, Aphis gossypii, Toxoptera aurantii)
|
Pest description:
Also called Black citrus aphid. Both winged and wingless forms are blackish in colour and shiny. They are sturdy and about 2 mm in length. The antennae of the winged form have a pale coloured fourth segment.
|
|
Typical Damage:
Copious amounts of honeydew are secreted and leaves and fruit may become black with sooty mould. Blossom drop and malformation of leaves may be caused but such direct damage is seldom severe. It is as a vector of tristeza stem pitting that this is a serious pest. The disease results in decline of grapefruit trees after 10-15 years or death of citrus trees within a year if budded on sour orange rootstock.
|
|
Dosage Table
30 ml / 100 litre water
|
EXCLUDING LEMONS AND KUMQUAT Add 250 ml Bac-Oil SO per 100 l water. Apply as a single light cover spray from 100 % petal fall and not later than 3 weeks after petal fall depending on infestation pressure based on scouting. Thorough coverage of the fruit is important. Preceding and successive applications with other products registered against thrips may be necessary depending on infestation pressure based on scouting. Calypso 480 SC thus forms part of a thrip spray programme. Should aphids be present during a Calypso 480 SC application, then simultaneous control will be obtained.
|
|