Different emergence phenology of European grapevine moth (Lobesia botrana, Lepidoptera: Tortricidae) on six varieties of grapes

Abstract

The phenology of insect emergence affects reproductive success and is especially critical in short-lived species. An increasing number of studies have documented the effects of thermal and other climatic variations and of unpredictable habitats on the timing of adult insect emergence within and between populations and years. Numerous interacting factors may affect the phenology of adult emergence. Host-plant quality and availability is a key factor that has been largely neglected in studies of the phenology of phytophagous insects. The purpose of this study was to determine the effect of host plant characteristics on the rate of larval growth and the pattern of emergence in a wild population of Lobesia botrana (European grapevine moth), a significant pest in European vineyards. The phenology of emergence differed significantly among the six tested varieties of grapes. The percentage of bunches harboring pupae was similar among the different grape varieties, and the total number of pupae collected was similar to the number of emerging adults per bunch. Among the six varieties of grapes, 0-25 pupae were produced on each bunch. Each of the grape varieties had a single wave of emergence, in which males emerged before females, but their emergence phenology differed significantly in Chardonnay, Chasselas, and Pinot grapes. Both genders had extended durations of emergence in Merlot grapes. Together, the present results show that the characteristics of the grape host plant affect the emergence phenology of L. botrana.

Climate warming effects on grape and grapevine moth (Lobesia botrana) in thePalearcticregion

“…In a similar study, Thiéry et al (2014) found a 1 : 1 ratio on six varieties of grape. We use sr = 0.5 in the model; hence, the total egg-load [E(t, T, diet l )] by all females of age x = 0 to x max at time t is:…”

“…Biodemographic functions describe the developmental rates and fecundity as affected by temperature and larval diet (berry stage), diapause induction and termination, and temperaturedependent mortality (Thiéry et al, 2014). Age-specific mortality as a result of temperature and other factors occurs in all life stages.…”

Organic farming and host density affect parasitism rates of tortricid moths in vineyards

“…Fields where very low larval populations (<10 individuals) were collected were not considered when analyzing moth and parasitoid community composition as well as parasitism rates. Grape cultivar was not included as an explanatory variable because vineyards were largely dominated by one cultivar (more than 65% of the vineyards sampled used 'Merlot' cultivar) and because it has been previously demonstrated that grape cultivar does not affect tortricid moths abundance and parasitism rates (Thiéry et al, 2014;Xuéreb and Thiéry, 2006).…”

“…These species are the major grapevine pests in Europe, and larvae naturally develop on most grapevine cultivars (Thiéry and Moreau, 2005;Thiéry et al, 2014). Larvae are polyphagous and can feed on berries (L. botrana and E. ambiguella) or on leaves and berries (A. ljungiana and S. pilleriana).…”

“…Therefore, parasitoid populations may disperse from other vineyards as well as from semi-natural habitats in the surrounding environment. However, the different factors affecting the distribution of tortricid moths and their natural enemies have mainly been studied at the field scale and nothing is known about the effect of farming systems and landscape context on these communities (Thiéry and Moreau, 2005;Thiéry et al, 2014).…”