Sawflies, such as apple sawfly (Hoplocampa testudinea) and Pear sawfly (H. brevis), are major pests in organic fruit production which can cause massive yield losses. Regulation is possible by only a few measures.

Combining different preventive strategies and direct measures can help to control the pest.

A combined strategy of different direct and indirect actions can lead to a long-term reduction of the apple saw-fly population in the orchards. Practical recommendation The need for regulation of the pest relates to the flower set strength. Regulation should be considered in years with weak flower sets or high infestation pressure. REGULATION OF THE APPLE SAW-FLY Indirect measures 1. Monitoring • Only for apple: Use predictive models (RIMpro, Fruitweb) to predict flight start (based on temperature development). • Use white sticky traps (Picture 1) before blooming to monitor first appearance and flight time. • Screen 100 flower clusters visually on egg-laying stitches on the Flower bottom (Pct.2). Depending on the abundance of flowers, the threshold is 1-4. 2. Mass-trapping • Apply White sticky tapes temporarily in the Orchards before flowering to catch the sawflies (150-250/ha). (see how in PA 24 (apple) and PA25 (pear) and the Video in the Links section). Caution: Research is still ongoing with promising results so far. Check with regional advisory services or the Biofruitnet Network for new findings. 3. Other indirect measures • Remove infested fruits manually in spring (reduces primary- and secondary infestation). Direct measures 4. Use of Quassia or NeemAzal T/S • Check the permission status of the products in your country. • Apply between full bloom (BBCH 65) and petal fall (BBCH 67, see Links section). o Quassia: Use a high water application rate (1000 l/ha) and add a wetting agent. o NeemAzal-T/S: Effect is postponed; first apple gets damaged. Damage to the second and third fruit is diminished. Caution on pears, check the susceptibility of varieties on phytotoxicity!

Christina Adolphi, Niklas Oeser
Tecniche produttive