Siver Y moth, Autographa gamma

Silver Y moth, Autographa gamma  is a serious insect of  sugar beet. It is distributed in North Africa and Mediterranean basin during winter; in summer, it occurs as far north as Scotland and Finland. In years of swarming, colonies of thousands of individuals could invade cultivated fields of red beet, potato, etc.

Pheromone for Siver Y moth, Autographa gamma

biologyof Autographa gamma Autographa gamma

Adult 40 to 45 mm wingspan. Brownish-yellow fore wings with. The hind wings are light brown, smoked at their periphery, the larva  40 to 45 mm, light green with 6 longitudinal whitish lines . Small and yellowish head, narrow anterior third of the body. Provided with 2 pairs of abdominal prolegs and one pair of anal prolegs, it moves about as a span-worm. The importance of the migrations leads to a geographical distribution of the species which differs considerably from season to season, so there is no distinct development cycle in any given place.

Nature of Damage

In years of swarming, colonies of thousands of individuals invade cultivated fields (red beet, potato, etc.). The older caterpillars are particularly voracious. Such invasions enable the development of numerous natural enemies of the caterpillar, particularly certain viral diseases whose effect is such that the second generation is almost non-existant.

Pheromone application guidelines

The following notes are guidelines of general nature and meant to give the user a head start in implementing pheromone monitoring programme. Local conditions and practices can very and can lead to customisation of the programme.

Trap selection

The Delta trap  is most sensitive trap to use for monitoring this insect. However, Moth catcher  may be used in dusty condition or in high moth population density. Do not re-use the trap to monitor different insects as this may lead to mixed catches.

Trap density

Two traps per hectare (2trap/ha) for small holdings and in field of uneven topography. One trap for every two hectares of large scale fields of homogenous lands.

Trap position

Near the highest point of the plant using supporting posts approximately 1 meter high or higher if the crop is higher.

Trap data and interpretation

Collect date weekly from the start of the flight of the over wintering generation.. During the height of the population more frequent reading may be needed. Decisions on pesticide application should not be taken solely on the trap catch data. Climatic and biological considerations should be taken in account.

Lures