Biological cycle

• Byctiscus betulae spends the winter as adults (figure 1) located 8 to 10 cm deep in the soil at the foot of the stumps, or under the bark of the trunk. They come out of hibernation between mid-May and early June, have a diurnal activity, and feed on green organs of the vine.

• The female rolls up the leaves and gives them the shape of a cigar to lay between 30 and 40 eggs (figure 2). We can see between 5 to 6 per cigar. Incubation lasts about ten days, and the young larvae formed feed on the blade of the rolled leaves during the first 3 to 4 weeks.

• They leave the "cigar" in mid-July and sink into the ground where they pupate. After 10 to 21 days, the nymphs rise give to adults which will remain in their compartments in diapause until the following spring.

• There is only one generation of the species per year. The activity of adults is favored by low temperatures and low humidity, unlike larvae.

• Synoptic of the development of Byctiscus betulae on vines   (figure 5)