Spread parameters of the borerXylotrechus Arvicola(Olivier) (Coleoptera: Cerambycidae) in a ‘Tempranillo’ vineyard in La Rioja (Spain): A long-term study

Rafael Ocete,Ignacio Armendáriz,José M Valle,Álvaro Rodríguez,Leire Usategui,Carlos A Ocete,Lara Maistrello

doi:10.1051/ctv/20203502148

Abstract

Xylotrechus arvicola(Olivier) (Coleoptera: Cerambycidae) is a polyphagous xylophagous beetle that is becoming a pest of increasing importance for vineyards in Spain, also because of the wood fungi developing in the galleries excavated by its larvae, which cause a progressive decline of the affected grapevines, until death. Between 1993 and 2015, a survey of the infestation caused byX. arvicolaand the symptoms caused by pathogenic wood fungi was performed in a ‘Tempranillo’ variety vineyard in La Rioja region (Spain). Maps showing the overtime spread of the borer and the diffusion of symptoms of grapevine decline andEutypadieback were obtained. Results indicated that the borer colonization began in the centre of the plot, followed by the first symptoms caused by the wood fungi a few years later. The statistical analysis showed that the evolution of infestation is characterized by a linear increase of new holes whereas the pattern of their allocation in the vines follows a bimodal distribution which, to some extent, can be simulated by a Poisson’s model. Based on these observations, a methodology to estimate the state of the infestation over time is proposed. The procedure - based on a linear regression of the average number of holes per vine over a set of years - can be applied in a relatively simple way and provides the probability for a grapevine to have a certain number of exit holes in a definite year with a mean error of around 5%.

Highlights

Wood-boring long-horned beetles can damage tree crops and important economic losses are being reported from all over the world (Grebennikov et al, 2010)
2003) symptoms were initially detected in the central part of the plot and spread out towards the borders until the almost complete infestation/infection of the vines
Since the first index has a significant coefficient of determination (R2 = 0.89), it means that the number of new holes grows steadily regardless of whether the plot is partially or totally infested; the regression adjusted to the second index, when only the already infested vines are considered, has a lower coefficient (R2 = 0.66)

Summary

Introduction

Wood-boring long-horned beetles can damage tree crops and important economic losses are being reported from all over the world (Grebennikov et al, 2010). Xylotrechus has over 180 species (Özdikmen and Tezcan, 2011). Xylotrechus arvicola (Olivier, 1795) (Coleoptera: Cerambycidae) is becoming an important pest in several Spanish vine-growing areas, which include many. Infestations by this borer were detected in plots of Prunus spinosa L., whose fruits are used in Navarra to produce a typical liqueur (Pacharán) (Biurrun et al, 2007), as well as in other stone fruit tree species like Prunus armeniaca L. A pheromone is produced by males to attract females (Hall et al, 2007; Rodríguez-González et al, 2017) but it is not effective in traps (Armendáriz et al, 2016). There is no indication of how adults localize vines, the use of visual clues, aggregation pheromones or specific kairomones might be involved, either alone or in combination

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