Plant Parasites of Europe

leafminers, galls and fungi

Cameraria ohridella cocoon

Cameraria ohridella cocoon

Aesculus hippocastanum, Nieuwendam

Mostly, when a fully developed mine is opened, this is how the cocoon looks: little more than a silken lining of the central part of the mine (also the place where the frass accumulates). Contraction of the silk cases the mine to pucker somewhat, perhaps as a protection against the ovipositors of parasitoids.

Cameraria ohridella cocoon

Aesculus hippocastanum, Nieuwendam

Less often an elaborate cocoon is made. Such cocoons serve during the hibernation (the picture was made in a fallen leaf, mid-November). But when the number of mines in a leaf becomes excessive already earlier, cocoons like these may be made already in summer; the pupa within goes into diapause, and awakens only next spring.

Last modified 20.ix.2018