Pest name : Moths (cabbage moth Mamestra brassicae, gamma moth M. gamma, tomato moth Lacanobia oleracea)
Host range of gamma moth is extremely broad, including vegetables, winter rape, potato, sugar beet, corn etc. Host range of cabbage and tomato moths is narrower - Cruciferous plants and/or other vegetables.
Larvae of all moths occur rather frequently on cole crops and may cause serious damages both by eating the leaves and by deposition of their feces on- or into consumable parts of plants.
Larvae feed on leaves gradually causing substantial loss of leaf surface. Finally only midribs may remain. Green balls of excrements are deposited on rest of foliage. During day larvae are usually not visible on damaged leaves because they are hidden in shady places or even in soil.
Secondary rots may develop in damaged tissues like cauliflower curds or cabbage heads.
Symptoms are very similar to those caused by larvae of white butterflies but in this case larvae are usually well visible on leaves during day.
of the pest:
All these moths are very similar, greyish brown coloured. Great variability exists in each species and between males and females. Species can be differentiated according to the presence of typical light spots on wings which have span about 4,5 cm. Eggs are greyish, structured on surface. Colour of larvae is rather variable from green through brown-green to almost black (cabbage moth). Lenght of larvae can reach up to 5 cm. Pupa is about 2 cm long, yellow-green (cabbage moth at the beginning) to dark brown or even black.
Pupa is the overwintering stage for cabbage and tomato moth but gamma moth may also immigrate from Southern Europe or can overwinter in any stage. Moths appear during May and feed on nectar from flowers. They are active in evenings and nights only. Females lay heir eggs individually or in groups on leaf underside. Larvae feed on leaves or inside of cauliflower curds or cabbage heads. Their development takes about 2 months. They pupate in soil or on plants (gamma moth). Moths of second and third generations appear in July or August.
- application of insecticides against young larvae when more than 10 % of plants are
infested. Application should be done after the sunset when larvae begin to feed.
|Active ingredience||Insecticide||Dose/ha, concentration||Last application before harvest (days)|
|deltamethrine||Decis 2,5 EC||0,3
|deltamethrine||Decis EW 50||0,15 l
|deltamethrine||Decis Flow 2,5||0,3 l
|deltamethrine||Decis Flow 2,5 Spray||1|
|deltamethrine||Delta Stefes||0,3 l
|lambda-cyhalothrine||Karate 2,5 WG||0,12 kg
|alpha-cypermethrine||Vaztac 10 EC||0,15 l
|alpha-cypermethrine||Vaztac 10 SC||0,15
Wetting agent should be added to the emulsion.