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Simple Summary: Many studies have shown that pesticide use has negative environmental effects. Therefore, alternative measures to manage insect pests and protect plant health are needed. Potential tools include chemicals that cause behavioral changes in pests and are already a part of the integrated pest management toolbox. Aphids are a significant pest in sugar beet (Beta vulgaris). They cause visual damage and act as vectors for various phytopathogens that reduce the yield. When attacked by predators, aphids emit an alarm pheromone, which causes other aphids to stop feeding, move away, and sometimes even abandon the host plant. We tested whether the artificially release of this pheromone could be an environmentally friendly alternative to prevent aphid infestation in sugar beet. Application of the pheromone resulted in reduced aphid densities in experimental sugar beet patches at two out of three experimental sites. This indicates the potential of this pheromone as an aphid repellent in sugar beet production. However, more research is required to ensure the reliability of this method. The negative impact of pesticides on the environment and the potential of pest species to develop pesticide resistance make it necessary to explore new methods of pest control. Pheromones and other behavior-modifying semiochemicals are already important in integrated pest management (IPM). (E)-ß-farnesene (EBF) is a semiochemical that acts as an alarm pheromone in aphids. Upon perception of EBF, aphids stop feeding, move away, and sometimes even abandon the host plant. The aphids Myzus persicae and Aphis fabae are significant crop pests and vectors of many harmful phytopathogens affecting sugar beet (Beta vulgaris). Field trials were conducted at different locations in Germany to test whether dispensers containing a mixture of farnesene isomers (FIMs) including EBF were able to reduce the infestation of these species on sugar beet. Our results showed a reduction in aphid abundance in the FIM-treated patches in two out of three sites. Therefore, we hypothesize that FIM dispensers could prevent aphid infestation and could be used in combination with other IPM measures. However, more research is required to increase the effect and ensure the reliability of this method. [ABSTRACT FROM AUTHOR]

Repeatable macroevolutionary patterns provide hope for rules in biology, especially when we can decipher the underlying mechanisms. Here we synthesize natural history, genetic adaptations, and toxin sequestration in herbivorous insects that specialize on plants with cardiac glycoside defenses. Work on the monarch butterfly provided a model for evolution of the "sequestering specialist syndrome," where specific amino acid substitutions in the insect's Na+/K+-ATPase are associated with (1) high toxin resistance (target site insensitivity [TSI]), (2) sequestration of toxins, and (3) aposematic coloration. We evaluate convergence for these traits within and between Lepidoptera, Coleoptera, Diptera, Hemiptera, Hymenoptera, and Orthoptera, encompassing hundreds of toxin-adapted species. Using new and existing data on ∼28 origins of specialization, we show that the monarch model evolved independently in five taxonomic orders (but not Diptera). An additional syndrome occurs in five orders (all but Hymenoptera): aposematic sequesterers with modest to medium TSI. Indeed, all sequestering species were aposematic, and all but one had at least modest TSI. Additionally, several species were aposematic nonsequesterers (potential Batesian mimics), and this combination evolved in species with a range of TSI levels. Finally, we identified some biases among these strategies within taxonomic orders. Biodiversity in this microcosm of life evolved repeatedly with a high degree of similarity across six taxonomic orders, yet we identified alternative trait combinations as well as lineage-specific outcomes. [ABSTRACT FROM AUTHOR]

Insect artificial diets are not only an important tool for mass rearing, nutritional research, and maintaining laboratory colonies but also for studying insect‐plant interactions. For herbivorous insects able to sequester plant toxins, feeding and sequestration assays based on artificial diet allow for the investigation of physiological, ecological, and evolutionary questions which may be difficult to study using real plants representing complex chemical environments. We developed a simple artificial diet, consisting of sunflower meal pressed into pills, for the milkweed bugs Oncopeltus fasciatus (Dallas) and Spilostethus saxatilis (Scopoli) (Heteroptera: Lygaeidae), which are capable of sequestering cardenolides and colchicum alkaloids, respectively. We assessed insect performance, suitability of the diet for sequestration assays, and its shelf life. Compared to sunflower seeds which are widely used as a laboratory maintenance diet for milkweed bugs, no differences were found in terms of weight development, presence of deformities, speed of development, or mortality. Importantly, after feeding O. fasciatus and S. saxatilis sunflower pills enriched with crystalline ouabain (cardenolide) or colchicine (colchicum alkaloid), respectively, sequestration was observed in both species. Moreover, as a prerequisite to test ecological hypotheses, our method allows for adequate concentration control and homogenous distribution of toxins across the diet. Under relatively warm conditions (27 °C and 60% r.h.), the new diet was stable for up to 10 days when used for feeding assays with adult bugs. Therefore, studies focusing on the role of plant toxins in predator–prey interactions and plant defense, but also insecticide research could benefit from using this approach. [ABSTRACT FROM AUTHOR]