Plants and insects have been interacting with each other for millions of years which have resulted in a coevolution, forcing both to maximize their fitness and not to be left behind in the race of survival. Insects select which individuals to graze on based on plant qualities that enhance their fitness, yet the factors influencing their choice remain understudied. This study aimed to elucidate why certain plant individuals suffer higher rates of herbivory within populations. Three plant species from different habitats in Scandinavia were surveyed: Sorbus aucuparia (rowan), Salix herbacea (dwarf willow), and Lactuca sibirica (Siberian lettuce). Using standardized protocols from the Herbivory Variability Network, 30 plant individuals were randomly selected in each site and surveyed for herbivore damage. Additionally, data were collected on the nearest neighbor of each plant (representing the same species), resulting in a total of 60 surveyed plants. Results revealed varied herbivory patterns among the species, indicating differential influences of plant size, growth stage, and neighboring plants on herbivory rates. An association between leaf and berry herbivory was found, suggesting that berries are less likely to sustain damage when leaves are already damaged. It suggests that trees retaining undamaged leaves are more proficient in photosynthetic processes and, thus capable of synthesizing berries enriched with higher concentrations of sugars and essential nutrients making them more attractive to insects. There is reason to believe that chemical defenses within the plants play an important role in the result seen in this study. This result provides insight into the behavior of insects, highlighting the complexity of plant-insect interactions and the need for further research to understand the factors driving herbivory patterns.

Sex ratio is very important for the evolution of dioecious plants. It can influence the reproductive success of plants. Sex ratio bias is common among reproductive individuals. Studying the reproductive traits can help to understand possible mechanisms that could influence the generation and maintenance of sex ratio bias. However, few studies have reported the relationship between reproductive traits and sex ratio bias. We investigated 29 full-sib families of the dwarf willow Salix herbacea L. S.herbacea exhibits an overall female sex ratio bias but also strong variation in sex ratio among families. We used variance component analysis to investigate from which morphological level the variation of reproductive traits (cumulative catkin number over four growth periods, annual catkin number in the fourth growth period, flower number, ovule number) came from. And we used mixed models to test the influence of family, sex and the sex by family interaction on reproductive traits. Besides that, we also tested the correlation between sex ratio and reproductive traits. Our results suggest that genetic factors can influence the degree of sexual dimorphism of S. herbacea in the different families Flowers from families with higher sex ratios had more ovules, sex ratio and the ovule number co-varied across families.