Effect of Colored Sticky Cards on Non-target Insects

Field experiments to evaluate four different colored sticky cards for trapping non-target insects were conducted in an organic maize field in the Heinigou region of China. Yellow, blue, green, and red sticky cards were used to trap insects in the field. The total number of insects species caught was 54, with 3,862 individuals recorded. Over half of the specimens caught were non-target insects, including phytophagous insects, particularly dipteran species(including many mosquitoes)(50.3%), followed by target pests(37.0%), and beneficial insects(12.7%). Statistical analysis revealed a significant difference in attraction to target pests, non-target pests, and beneficial insects among treatment groups. The results showed that higher numbers of target pests(Myzus persicae Sulzer, Empoasca flavescens Fabricius, Nysius ericaecshinly Schilling) were caught on yellow sticky card traps compared with blue, green, or red sticky card traps, indicating that yellow was the best trap color for target pests, with green and blue being progressively less attractive. For non-target insects, including phytophagous insects, flies, and mosquitoes,higher numbers of were caught on blue sticky card traps compared with yellow,green, or red sticky card traps. Our study indicated that blue was the most attractive color for flies, especially for the housefly, Musca domestica Linnaeus. Our study also showed that most beneficial insects exhibited preferences to particular trap color characteristics: yellow was the most attractive color for parasitic wasps and lady beetles; blue was the most attractive color for hoverflies and honeybees. In contrast,green and red had no significant attraction to beneficial insects.

Tri-Trophic Interactions within Potato Agro-Ecosystem, Qassim, KSA

Tri-trophic interactions between fertilizer applications, cotton aphid (Aphis gossypii Golver) and associated beneficial insects were studied to investigate direct and indirect effects of fertilizers (types and ratios) on potato plants under field and greenhouse conditions, A. gossypii and associated beneficial insects. Fertilizers regimes showed direct impacts on the potato plant phenology and indirect effects on both A. gossypii population and the associated beneficial insects. Our data indicated that potato plants had been influenced by fertilizer elements used within tri-trophic system comprising potato plants, cotton aphid, and certain associated beneficial insects. This demonstrates that a bottom-up interaction is robust and has a particular value in the attraction of beneficial insects towards the potato plant signals due to used fertilizers which can also have a function when plants are attacked by A. gossypii. Yet, flexibility in the use of fertilizers (as chemical cues) is conserved, and that may help beneficial insects to specifically focus on the odor of plants that carry potential plant hosts and avoid plants that are only attacked by non-hosts. These results support the still controversial notion that fertilizer elements, at least in part, help plants to serve as functional signals to attract the enemies of the harmful insects. These observations declare the benefits of the tri-trophic interactions as an ecological phenomenon in particular and the food chain in general. Additionally, this study may be useful to be used as a predictable model with the associated beneficial insects which may have key roles in overall aphid suppression or regulating its population. Impact of fertilizers on potato phenology characteristics and the cotton aphid population density seems to be variable based on types and ratios of the fertilizers. Interfacing the impact of natural enemies (plant-pest-natural enemies) through tri-trophic relationship within the food chain verified to be straightforward way of predicting on the impact of beneficial insects-guild on the cotton aphid population density.