Control of the apple sawfly Hoplocampa testudinea Klug in organic fruit growing and possible side effects of control strategies on Aphelinus mali Haldeman and other beneficial insects

Summary in the original language of the document

The effect of Quassia extract on eggs and larvae of the apple sawfly Hoplocampa testudinea
was studied. The efficacy of this extract is mainly due to an oral toxicity to the
neonate sawfly larvae. The main active ingredients, Quassin and Neoquassin, were
tested separately. Wheras Quassin has a considerable efficacy also on older larvae,
Neoquassin is less efficient in this case. While Quassin and Neoquassin are found in
different Quassia sources in varying relations to each other and have different efficacy,
they have to be considered separately in the definition of extract quality by the content of
active ingredients. These findings mean, that the “egg maturity” is not important for application
date. Nevertheless, the application must take place before the larvae hatch. It
was shown that low rates of Quassin (4-6 g/ha) can show very good results in the field,
in other cases the rates necessary for good efficacy are much higher. This corresponds
to farmers experience. Several factors as application technique and the condition of the
blossom must be taken in consideration and will be object of further studies.
The side effects of Quassin, Neoquassin and Quassia extract on Aphelinus mali and
other beneficial arthropods were tested. Quassia is harmless to all organisms tested.