No broccoli without a head: biocontrol of the Swede midges (100%) | jobs fibl

Type of offer: Master these

Background

In this project you will investigate in field trials different strategies that can be used control the swede midge, a pest on broccoli. The challenge is how to best interfere with the pest life-cycle.  Management of swede midge is particularly challenging and a single swede midge larva can render cauliflower or broccoli unmarketable. The Swede midge is a challenging pest to control, both in conventional and organic farming, for a number of reasons: 1) It has a crypt behaviour, feeding from growing points and inside the leaf stalks. A single larva can hinder the formation of the broccoli or cauliflower head. Because of its hidden feeding behaviour, foliar applications of insecticides are unlikely to kill the larvae. 2) With up to five overlapping generations within a season, a small number of Swede midge adults in the first generation can give rise to tens of thousands by the third generation in July. 3) Swede midges overwinter in the soil, and by late September, high numbers will burry into the soil to pupate, creating challenging management issues for the following growing season when they emerge in very high numbers in spring, or even up to two years later. 4) Due to their minute size, Swede midges get carried by the wind easily and can spread up to a kilometre away, challenging the use of rotation as a management strategy.

Approach/Methods

There will be several opportunities to optimize experiments and study how to best interfere with the life cycle to the swede midge in field conditions

• Automated monitoring: correlate climate data with pest population dynamics to improve timing of application of measures
• Mass capture: specificity of light colours used in traps for the swede midges
• Improve counting methodology with digitization
• Push and Pull: efficacy of multiple strategies (possible combined tests of light traps + companion plants)

Contact

Dani Lucas-Barbosa, Pascal Herren, Lara Reinbacher

Starting date

From April/May 2025