Efficacy of some entomopathogens against Ephestia cautella (Walker) (Lepidoptera: Pyralidae) in stored date fruits
Abstract: Background: Ephestia cautella (Walker) (Lepidoptera:Pyralidae) is one of the most economically important date fruits
insect pests, which causes major losses in quantity and quality of the date yield. The present study aimed to evaluate
3 of the entomopathogens: Beauveria bassiana (Basonym 1836), Metarhizium anisopliae (Metchnikoff 1879), and Bacillus
thuringiensis (Berliner 1915) var. kurstaki individually and mixed with each other against E. cautella in stored date
fruits.
Results: Four concentrations from spores’ suspension of each entomopathogen were sprayed on 50 eggs of E. cautella
(24:48 h. old) (for fungal pathogens) and 30 2nd instar larvae of E cautella in glass jars. Pathogenicity was evaluated
at different time intervals post treatments 3, 5,7and 14 days. Obtained results showed that mortality percentages
of E cautella stages increased by increasing the tested entomopathogen concentrations and increasing of the exposure
time. Results indicated that the reduction percentages of E. cautella eggs hatchability after separately treated at
the concentrations (3.0 × 105,
3.0 × 106,
3.0 × 107
and 3.0 × 108
spores/ml) were (27.50, 39.17, 48.33 and 62.50%) for
B. bassiana, (35.83, 44.17, 50.83 and 69.17%) for M. anisopliae, respectively. After14 days of treatment, the recorded
larval mortalities were (49, 62, 77, and 81%) for B. bassiana and (60, 66, 78, and 89%) for M. anisopliae at concentrations
(3.0 × 105,
3.0 × 106,
3.0 × 107and
3.0 × 108
spores/ml), respectively. In case of treating E. cautella larvae with B.
thuringiensis, the mortality percentage was (44, 52, 63, and 72%) at concentrations (2.0 × 108,
2.0 × 109,
2.0 × 1010
and
2.0 × 1011
spores/ml), respectively, after14 days of exposure. E. cautella larvae were more susceptible to B. bassiana and
M. anisopliae than the eggs. M. anisopliae was more effective than B. bassiana. The combination of the entomopathogens
LC50 (B. bassiana + M. anisopliae, B. bassiana + B. thuringiensis, M. anisopliae + B. thuringiensis and B. bassiana + M.
anisopliae + B. thuringiensis) caused E. cautella larval mortality percentages of 67.00, 73.33, 63.33 and 86.29%, respectively,
14 days after exposure. The combination of the 3 tested entomopathogens (B. bassiana + M. anisopliae + B.
thuringiensis) increased their efficacy for controlling E. cautella.
Conclusions: The combination of the tested entomopathogens: B. bassiana, M. anisopliae and B. thuringiensis could
be recommended for controlling E. cautella stages in stored date fruits.
Publication year 2022
Organization Name
Author(s) from ARC
Publication Type Journal
↑