Population dynamics and biological parameters of Aphis fabae Scopoli on five broad bean cultivars
By: Fouad Meradsi, Malik Laamari
Key Words: Aphis fabae, Biological parameters, Demographic parameters, Resistance, Vicia faba.
Int. J. Biosci. 9(2), 58-68, August 2016.
Understanding how host-plant characteristics affect biological and demographic parameters of insect herbivores is of considerable importance in the development of resistant crop cultivar. Biological and life table parameters of the black bean aphid, Aphis fabae Scopoli (Homoptera: Aphididae), were estimated on five broad bean, Vicia faba L. (Fabales: Fabaceae) cultivars (4, 11, 12, 13 and 14) at 17 ± 5°C, 70 ± 10% Relative Humidity and a photoperiod of 14: 10 (L: D)h. The experiment was arranged in the randomized complete block design (RCBD) and there were eight replications (plants) for each treatment (cultivar). The nymphal rate mortality of A. fabae was significantly different among cultivars (P = 0.028; χ2 9.48 = 10.91). The cultivar 12 induced the highest mortality rate (26.83%), whereas the cultivar 4 caused the lowest mortality rate (4.65%). The results showed significant differences among the five cultivars for the following biological parameters: the adult size (F3.36 = 3.391; P = 0.049), the adult weight (F3.18 = 3.260; P = 0.047) and the total number of embryos (F3.48 = 5.513; P = 0.013). The poor performances of A. fabae were recorded on the cultivar 12 (2.54 mm2 of size, 0.87 mg of weight and only 20.33 embryos in mean) in comparison to other cultivars. The number of developed embryos and all demographic parameters of black bean aphid were not significantly different between the cultivars (P > 0.05). The partial correlation showed no relationship between all biological parameters tested except the total number of embryos and the number of developed embryos; there was a positive low correlation between the two parameters (r = 0.568; P = 0.03). The present study revealed that the resistant cultivar 12 have insecticidal power and a negative effect on the performances of A. fabae adults and could be used as an alternative to conventional synthetic insecticides in an integrated pest management program to A. fabae.