Test No. 226: Predatory mite (Hypoaspis (Geolaelaps) aculeifer) reproduction test
in soil
This Test Guideline describes a method to assess the effects of chemical substances
in soil on the reproductive output of the soil mite species Hypoaspis (Geolaelaps)
aculeifer Canestrini (Acari: Laelapidae). It can be used for water soluble or insoluble
substances, but not with volatile substances.
Adult females of similar age are exposed to a range of concentrations of the test
substance mixed into 20 g dry mass of artificial soil 28-35 days after the start of
the egg laying period. Depending on the endpoint (ECx, NOEC or both), five to twelve
concentrations should be tested. At least two to four replicates for each test concentrations
and six to eight control replicates, of 10 animals each, are recommended. At 20¡ãC,
the test lasts 14 days after introducing the females, which usually allows the control
offspring to reach the deutonymph stage. The number of surviving females (mortality ¡Ü 20%
for a valid test) and the number of juveniles per test vessel (at least 50 for a valid
test) are determined. The fecundity of the mites exposed to the test substance is
compared to that of controls in order to determine the ECx (e.g. EC10, EC50) or the
No Observed Effect Concentration (NOEC). Any observed differences between the behaviour
and the morphology of the mites in the control and the treated vessels should be recorded.
Published on July 29, 2016Also available in: French
In series:OECD Guidelines for the Testing of Chemicals, Section 2: Effects on Biotic Systemsview more titles