Impact and management of the eriophyoid mite Trisetacus juniperinus on the evergreen cypress Cupressus sempervirens

Abstract

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.

An insight into some relevant aspects concerning eriophyoid mites inhabiting forests, ornamental trees and shrubs

“…For example, unlike other gall-forming arthropods, the gall mite of wild cherry (Prunus serotina), namely Eriophyes cesaricrumena (Walsh), not only has a negative effect on the photosynthetic rate of galled leaves, but also on gall-free leaves of the same shoot (Larson 1998). In the case of nursery infestation involving T. juniperinus, the detrimental effects on tree development were observed even 2 years after transplanting (Castagnoli et al 2002) and even after mites had died or left the tree (Simoni et al 2004).…”

“…Another long-term study focused on the evaluation of the impact of mite infestation both on the survival and apical growth of two commercial cypress clones (Agrimed and Bolgheri) and the differently timed pesticide applications to suppress mite populations on newly grafted trees (Simoni et al 2004). The experiment was conducted in a large specialized nursery in Central Italy where 1 year old seedlings were obtained from seed harvested in selected stands and grown individually in pots in a greenhouse.…”

Adventive eriophyoid mites: a global review of their impact, pathways, prevention and challenges

“…In temperate and tropical fruit tree crops, Aculus schlechtendali (Nalepa) is a pest of apples in Europe (Easterbrook 1996;Gólya and Kozma 1998;Angeli et al 2007) and Aceria guerreronis Keifer is an important pest of coconut palms, Cocos nucifera L., worldwide (Moore and Howard 1996;Fernando et al 2002;Nair et al 2005). In cereal crops, Aceria tosichella Keifer is a widespread pest of wheat and corn (Oldfield and Proeseler 1996;Harvey et al 2002) and in forest and ornamental trees, Trisetacus juniperinus (Nalepa) is a pest of evergreen cypress in Europe and North America (Castagnoli 1996;Castagnoli et al 2002;Simoni et al 2004).…”

Diversity and significance of eriophyoid mites (Acari: Eriophyoidea) associated with coniferous trees in Poland: a review

“…This may result from: (i) a long period of symptom development, which induces problems with mite detection, e.g. 2 years after transplanting (caStagnoLi et al 2002) or even after the mites died or left the tree (SiMoni et al 2004); ii) difficulties in sampling from large-sized and old trees (caStagnoLi et al 2010); iii) the diversity of microhabitats that may be inhabited by these mites and diverse mite strategies as well as frequently observed low population densities (which makes it necessary to collect very large samples from various plant parts); iv) the existence of cryptic diversity within eriophyoids inhabiting coniferous plants, which may confound the systematics of this group and, moreover, is crucial for the development of effective management strategies for these pests .…”

“…In the Mediterranean region, T. juniperinus and fungal cypress canker, Seiridium cardinal (wag) Sutton & giBBSon, constitute a major problem for young, cultivated plants. For the latter (SiMoni et al 2004). For example, T. quadrisetus (thoMaS) is known as a pest of Juniperus communis, and its large populations on berries cause total destruction of the seeds.…”