Evolutionary and Applied Insights into Hazelnut Resistance to the Pre-Dispersal Seed Predator Curculio nucum L.

The primary mission of the lab of the "Association des Producteurs de Noisettes (ANPN)" is to minimise the impact of pathogen disease to the hazelnut quality and to select hazelnut cultivars. The ANPN has a strong experience in biocontrol and is a major actor in pest control in French hazel orchards. The ANPN is a partnership with INRAE since 1995 and the head leader of the European project against stink bugs (REPLIK) and against the nut weevils and the indian meal moths (BALAMITE). The ANPN also works on the evaluation of new hazelnut cultivars and their adaptability to various growing conditions such as planting density, rootstock effect, soil and climate conditions or phenology (OPTIVAR). More details at

Scientific background

The hazelnut weevil (Curculio nucum L.) is the unique pre-dispersal seed predator of European hazelnuts (Corylus avellana L.), capable of infesting up to 80% of nuts [1]. Host and its predator have coevolved, and one key hypothesis is that the rate of shell hardening represents a host defence that creates a trade-off between resistance to the weevil and nut development [2]. Oviposition occurs within a narrow phenological window when the shell is penetrable; outside this window, larvae may fail to enter or become trapped inside the nut, creating an evolutionary dead end.

Goals

The intern will construct a phenology-based varietal risk matrix using degree-day accumulation and shell hardness dynamics, and quantify the evolutionary trade-off between defence and reproduction across cultivars. This framework will also provide actionable insights for IPM, including cultivar selection and timing of control measures.

Strong interest in plant-insect interactions, coevolution and IPM. Prior practical experience is an advantage, particularly in using a penetrometer, performing insect dissections and conducting statistical analyses with R, or similar tools. A driving licence is required to access the field.