Detection of the Early Sensitive Stage and Natural Resistance of Broad Bean (Vicia faba L.) Against Black Bean and Cowpea Aphids

Broad bean is one of the most important leguminous crops worldwide. However, its productivity is greatly affected by the infestation of Aphis fabae and Aphis craccivora (Hemiptera: Aphididae). The main objective of the current study was to identify the most susceptible phenological stages of the broad bean variety (Histal) against black aphids&rsquo: herbivory. This had been achieved through an evaluation of plant resistance mechanisms such as antixenosis and antibiosis. The results regarding an antixenosis test revealed that the four tested phenological stages of V. faba did not have a significant effect on the preference of A. craccivora and A. fabae towards the crop plant. Overall, a slightly higher number of adults settled on the three and four unfolded leaves&rsquo: stage of the crop plant. Similarly, the highest number of developed embryos were found in the four leaves&rsquo: stage of the crop, and the lowest in the second leaf stage. The adult body size of A. craccivora was slightly larger in the case of the three unfolded leaves. Furthermore, the maximum body size of A. fabae adults was recorded in the case of the first unfolded leaf stage crop. Linear correlations between the biological parameters for both species revealed only one significant relationship between developed and total embryos for A. craccivora. The results of the current study highlight the need to protect broad bean crops against infestations of black aphids, i.e., A. craccivora and A. fabae. This is essential for reducing direct damage and preventing the transmission of phytoviruses. However, future studies should aim to evaluate the susceptibility of all developmental phenological stages of the crop against black aphids to mitigate potential crop losses.