Different Population Phenologies of Grapholita molesta (Busck) in Two Hosts and Two Nearby Regions in the NE of Spain

Abstract

Grapholita molesta is an important pest of stone and pome fruits. In commercial orchards, integrated pest management programs use pheromone traps to monitor the population dynamics of G. molesta and adjust treatments. Phenology models can be used to forecast the population phenology of pests and to help optimise the time point at which to spray the orchards with insecticides. In the present study, the adult population phenologies of G. molesta in two provinces of north-east Spain were studied, as well as their fit to the phenology model most used in both provinces. Weekly captures of adults in pheromone traps through the season were recorded over 5 y in a large number of commercial orchards, and these data were used to determine the number of generations of G. molesta in each province. The results show significant differences between provinces in the generation time, being 97 degree days (DD) shorter in the Lleida province than in the Girona province. In Girona province, four generations were registered, while five were detected in Lleida. As a result of the differences found, the phenology model was not able to predict precisely the population dynamics in the Girona province.

Degree-day risk thresholds for predicting the occurrence of Anarsia lineatella, Grapholita molesta and Adoxophyes orana in northern Greece peach orchards

“…Moreover, as the season progresses, there is higher variation in the last moth flights observed that can be related to the extreme high temperatures observed during the summer which slow down the development and might cause bimodal peaks and overlapping of the generations. This was also seen as an evident trend in other phenology studies (Kocourek & Stará 2005;Milonas & Savopoulou-Soultani 2006;Knight 2007;Amat et al 2021). Finally, other factors, such as predation, or the application of pesticides and/or mating disruption, as well as the type of lure might also affect the number of moths that are finally captured during the study (Knight 2010;Damos & Savopoulou-Soultani 2012;Damos et al 2014;Preti et al 2020).…”

Identification and Characterization of CYP6 Family Genes from the Oriental Fruit Moth (Grapholita molesta) and Their Responses to Insecticides

“…Specifically, this pest affects the yield and quality of crops by drilling into fruits and sprouts [ 1 , 2 , 3 ]. Due to the increases in the orchard area and climate change, the population of G. molesta has increased sharply and the damage to fruit trees has become increasingly severe [ 3 , 4 , 5 ]. The chemical control of this pest remains the dominant strategy, but the repeated use of large amounts of chemical pesticides has led to the development of resistance in this insect [ 6 ].…”