CONTROL OF PHORBIA BRASSICAE IN CAULIFLOWER: RESISTANCE TO LINDANE AND RESULTS OF APPLICATION OF CHLORFENVINPHOS

Since more than 30 years Lindane has been applying for control of cabbage root fly in the GDR. A decreasing efficacy of Lindane was observed in practice in the last years.

For this reason a special discrimination test was developed, to decide, whether a population is resistant to Lindane or not.
Round filter paper in petri dishes of 90 mm in diameter is contaminated with a Lindane preparation from 240 μg a.i. per filter and settled with 10 larvae of cabbage root fly in range of 4…6 mm body length, which were taken out from infested cabbage plants.

6 replications with altogether 60 maggots are necessary in minimum. 3 hours after exposition the moving behaviour of the larvae is estimated.
Resistance is indicated, when the movement of more of 5 % of the maggots is still normal and the colour of the body ist not yet changed.
Regarding an alternative for Lindane in the control of cabbage root fly, Chlorfenvinphos preparations were tested with different application methods.

Under conditions of a high infestation pressure we found, that 1.4…1.5 kg/ha Chlorfenvinphos, poured with 100 ml water per plant or with 2000… 3000 l water over the rows after planting gave an effectiveness from more than 88…90 % over a time from 6…8 weeks.

Also a band spraying with 600 l/ha reached a sufficient control.
Convenient possibilities of preplanting control offer the mixing of 100 g Chlorfenvinphos under 1 m³ of soil, and the oversprinkling of plants a short time before planting in the field with 0.0375…0.046 g a.i. per plant.

International Symposium on Diptera Pests in Vegetable Crops

W. Pallutt, D. Otto

https://doi.org/10.17660/ActaHortic.1988.219.11