Impact and management of the eriophyoid mite Trisetacus juniperinus on the evergreen cypress Cupressus sempervirens
1 In the Mediterranean region, the eriophyoid mite Trisetacus juniperinus causes considerable damage to the evergreen cypress, Cupressus sempervirens L., particularly in nurseries and young stands, disturbing the apical growth of the tree.
2 The impact of mites on survival and apical growth of two commercial clones of cypress (Agrimed and Bolgheri), as well as the results of differently timed pesticide applications to suppress mite population on newly grafted trees, were evaluated.
3 Mites easily infested clonal scions from rootstocks that were previously infested in the nursery, inducing tip deformation and disturbance of the growth. Apical growth was significantly lower in infested than in control trees 2 years following the graft.
4 Deformed apical buds were left early by mites, which dispersed in the crown and may have incurred high mortality. This is interpreted as a defensive reaction of the cypress to the mite attack, which involves costs resulting in reduced apical growth in both clones. However, mites partly overcame tree defences in the Bolgheri clone.
5 Healthy rootstock and graft material should be used to limit damage and maintain plant growth because natural infestations rarely occur. In case of attack, a pesticide should be applied as soon as possible because precocious mite infestation has a log-lasting effect on tree growth, with considerable economic damage.
Document Type: Research Article
Affiliations: 1: MIPAF − Istituto Sperimentale Zoologia Agraria, Via Lanciola 12a, 50100 Firenze Italy, 2: CNR − Istituto Protezione Piante, Piazzale delle Cascine 28, 50144 Firenze Italy and 3: Università di Padova, DAAPV-Entomologia, Via dell'Università 16, 35020 Legnaro, Italy
Publication date: August 1, 2004