Functional Response and Intraspecific Competition of Three Ladybird Species Feeding on Aphids on Goji Berry Plants in Laboratory and Semi-Field Conditions

Abstract

The aphid, Aphis gossypii Glover, is identified as a significant pest that causes severe damage to goji berries in China. To analyze the ladybird consumption of aphids, the functional responses of three ladybird species, Harmonia axyridis, Coccinella septempunctata, and Hippodamia variegata, and intraspecific competition among ladybird individuals were evaluated under laboratory conditions. Moreover, the practical impact of ladybirds on aphid population reduction was investigated in semi-field conditions. We found that all adult ladybirds of the three species exhibited a type II functional response toward aphids. According to Holling’s disc equation, H. axyridis exhibited the highest searching efficiency (a = 0.79), while C. septempunctata had the shortest handling time (Th = 5.07 min) among the three ladybird species studied. Additionally, intraspecific competition had a greater impact on H. variegata (m = 0.41) compared to the other two ladybird species. The semi-field study demonstrated that H. axyridis (83.9% reduction) and C. septempunctata (78.7% reduction) exhibited higher efficacy in reducing aphid populations compared to H. variegata (27.3% reduction). This study suggests that H. axyridis and C. septempunctata exhibit potential as effective biological control agents against aphids on goji berry plants and highlights the importance of considering intraspecific competition. However, the results obtained from laboratory and semi-field studies cannot be directly extrapolated to field conditions due to the simplification of these experimental systems. Future field studies are crucial in ensuring the effective implementation of a biological control program.

Effects of Various Nectar and Pollen Plants on the Survival, Reproduction, and Predation of Neoseiulus bicaudus

“…To further explore the impact of pollen on N. bicaudus cultivation, this study examined the functional response of N. bicaudus when preying upon T. turkestani in the presence of pollen [ 63 ]. The results showed that the predatory functional response of N. bicaudus to T. turkestani still fits the type II response when provided with C. cyanus pollen, B. officinalis pollen, and C. monnieri pollen, thereby indicating that the addition of pollen did not alter the feeding model [ 64 , 65 ]. This is consistent with a previous study [ 66 ], in which the presence of Typha orientalis pollen did not alter the functional response type of Neoseiulus cucumeris .…”

Comparison of Predatory Performance among Three Ladybird Species, Harmonia axyridis, Coccinella septempunctata and Hippodamia variegata, Feeding on Goji Berry Psyllid, Bactericera gobica

“…The direction and angle of prey are typically perceived with exceptional acuity by predators, facilitating their target localization [45,46]. The rapid prey location recognition based on reference objects in its surroundings is more pronounced in H. axyridis compared to H. variegata [47]. Flight is the predominant mode of locomotion for H. axyridis during foraging, while crawling is the primary means of movement for H. variegata [48].…”