Aphid population abundance and pestiferous effect on various bean plant species

The population abundance, infestation, and harmful effects of the aphidAphis craccivoraKoch (Hemiptera: Aphididae) were studied on four bean plant species, namely the country bean (Lablab purpureusvar. BARI Seem 1), the yard-long bean (Vigna sesquipedalisvar. BARI Borboti 1), the hyacinth bean (Dolichos lablabvar. BARI Seem 6), and the bush bean (Phaseolus vulgarisvar. BARI Jar Seem 3). Aphid abundance and infestation on the leaves, inflorescences, flowers, and pods differed significantly among the bean plant species, withP. vulgarisandV. sesquipedalishaving the lowest and highest results, respectively. Aphid severity grade and the number of trichomes of the bean plant species were negatively correlated. The duration of the growth stages among the bean plant species were significantly different, withV. sesquipedalishaving the shortest durations. Aphid abundance and infestation significantly affected the physical and phytochemical characteristics of the bean plant species. The highest reduction of number of leaves, flower inflorescences, and pod inflorescences per plant, and moisture and chlorophyll content in the leaves was found inL. purpureus. The results forV. sesquipedalisrevealed the highest reduction in plant height, seed weight, and pH, while those ofD. lablabshowed the highest reduction in leaf area.