Abstract
Diverse herbivores are known to induce various plant defenses. The plant defenses may detrimentally affect the performance and preference to subsequent herbivores on the same plant, such as affecting another insect’s feeding, settling, growth or oviposition. Here, we report two herbivores (mealybug Phenacoccus solenopsis and carmine spider mite Tetranychus cinnabarinus) which were used to pre-infest the cucumber to explore the impact on the plants and the later-colonizing species, whitefly Bemisia tabaci. The results showed that the whiteflies tended to select the treatments pre-infested by the mites, rather than the uninfected treatments. However, the result of treatments pre-infested by the mealybugs was opposite. Total number of eggs laid of whiteflies was related to their feeding preference. The results also showed that T. cinnabarinus were more likely to activate plant jasmonic acid (JA) regulated genes, while mealybugs were more likely to activate key genes regulated by salicylic acid (SA). The different plant defense activities on cucumbers may be one of the essential factors that affects the preference of B. tabaci. Moreover, the digestive enzymes and protective enzymes of the whitefly might play a substantial regulatory role in its settling and oviposition ability.
Highlights
In nature, plants possess a considerable diversity of resistance strategies and produce complex chemical reactions after experiencing mechanical damage or attacks by herbivores (Green and Ryan, 1972)
The percentages of B. tabaci that settled on the treatments with T. cinnabarinus were significantly more than those on the control treatments without T. cinnabarinus (12 h, P = 0.008; 24 h, P = 0.002; 36 h, P = 0.003; 48 h, P = 0.009; 60 h, P = 0.007; 72 h, P = 0.007) (Figure 1)
Less whiteflies settled on the plants infested with P. solenopsis (12 h, P = 0; 24 h, P = 0.001; 36 h, P = 0; 48 h, P = 0.001; 60 h, P = 0.005; 72 h, P = 0.014) (Figure 1)
Summary
Plants possess a considerable diversity of resistance strategies and produce complex chemical reactions after experiencing mechanical damage or attacks by herbivores (Green and Ryan, 1972). The JA and ET pathway are induced against necrotrophic pathogens, chewing herbivores and cell-content feeders (Thaler et al, 2012; Godinho et al, 2016). The SA signaling pathway is primarily induced by bio-trophic pathogens and piercing- sucking herbivores, resulting in minimal tissue damage (Arena et al, 2016). The herbivores may induce the accumulation of SA by attacking host plants and utilize this accumulation to inhibit JA-mediated defenses. Interference between the plant defense pathways may occur
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
