# 5.3.4. Statistical analysis

1) The validity of a test depends on some data validity range.

2) In negative reference samples, larval mortality
(number of dead larvae/48), pupal mortality (number of dead pupae at D22/number
of alive pre pupae at D7) and adult mortality (number of dead emerged bees at
D22/total number of emerged bees) must be lower or equal to 15% for the
assessment of LD_{50} or LC_{50},
or 20% for the assessment of NOAEL or NOAEC. In case of higher mortality in the
control sample, the replicate is invalidated.

3) The mortality rate with positive reference (dimethoate) must be:

- higher than or equal to 50% at D6 for larvae
exposed to 3µg/larva at D4

- higher than or equal to 50% at D7 in chronic
exposure of larvae to the concentration 20,000µg/kg diet.

4) The calculated LD_{50} and LC_{50} must in each case be between the two
extreme tested doses. They must not be extrapolated out of the tested limits.

5) Any deviation from the above conditions will invalidate the test.

6) LD_{50} and LC_{50}
are calculated from mortalities expressed in percentage of the reference
populations after an adjustment according to the Abbott or Shneider-Orelli
formula (see section 8.4.1.).

6) The results will be analysed using regression model with high adjustment level, which can be checked with the determination coefficient value (Abbott, 1925).

7) Basing on the same raw mortality data, the NOAEL and NOAEC are assessed (see section 8.4.3.).