Abstract:
The current study aims to evaluate the effectiveness of four extracts of
Citrullus colocynthis (L), a plant collected from the Dhayet Ben Dhahoua region
(Ghardaia) against the red flour beetle insect Tribolium castaneum, as part of
research on alternative control methods against insect pests of stored grains.
Different fractions were extracted from C. colocynthis by maceration using
different solvents with diverse polarities. These extracts allowed us to achieve that
crud extracts (MeOH/H2O and EtOH/H2O) obtained the highest yields (25.85%
and 23.8% respectively) compared to the fractions.
The application of these fractions on the flour beetle insect was performed
with two methods, contact and ingestion, using three doses/method/extract. The
results showed that all the extracts have a toxic potential against this pest noting
that the highest mortality rates were recorded by tannin extract (>50%), while the
flavonoid extract showed the lowest mortality rate (<25%).
Depending on the method of application, the contact mode showed greater
effectiveness (>50%) than the ingestion mode (<25%). Furthermore, depending on
time, the period of three days was more effective than the other times (mortality >
50%). In contrast, for doses, the biggest dose (750 mg/mL) was the most effective
among the doses given. The use of this biopesticide can promise to protect stored
grains from beetle infestation and reduce the risk of secondary human exposure.
