Ants are an important part of biodiversity and are useful bioindicators. Our aim was to determine whether ant species richness and composition differ among large clear-cuts (ca. 3000 m2), small for...

The division of functions among ant workers and their mutual cooperation is one of the reasons for ants’ success. The activities that workers perform in the nest can be divided by age or morphology. We studied the body size of workers of the wood ant Formica polyctena as a function of their activity. Our results show that workers exploiting protein baits were larger than workers attracted to carbohydrate baits. The biggest of all were workers located at the upper parts of the nest, which shows the importance of nest defense and maintenance. It also points that the distribution of functions does not have to be given only by workers age. Work division based on several mechanisms may be advantageous for colony functioning.

Food availability is an important factor influencing the lives of ant colonies. Wood ants consume protein-rich and sugary foods. Protein-rich food is comprised primarily of insects, a considerable proportion of which the ants acquire by direct predation. They therefore play an important function in biological protection of forests. The objective of our study was to determine if workers activity is dependent on habitat type, size of the nest, bait size and food type (sugar, protein). We selected 23 nests in a spruce forest and placed food baits of various sizes and types near each nest. The results obtained show that the number of individuals on the baits was substantially higher in clearings than within mature forest. The number of worker ants recorded on the baits was slightly higher for larger nests. Bait size and type had no influence on the number of workers present. Because wood ants do not focus solely on food of a certain size or quality, they can effectively decrease the abundance of forest pests.

Central European coniferous forests are facing the most significant bark beetle outbreak in history. The consequence is the creation of large clearings, which are associated with changes in environmental parameters. We studied how these changes affected the survival of wood ant nests. Specifically, we monitored the relationship between mound occurrence, tree coverage, and the coverage and height of vegetation on ant mounds. We found that wood ant nests were less likely to survive (39% decline) in bark beetle-affected forests than in unaffected forests. The Formica rufa species was more affected than F. polyctena. The bark beetle attack was significantly positively correlated with increases in understory vegetation cover and height. Several factors may explain the negative effects of bark beetles on wood ants. The removal of trees subsequently increased the amount of light on ground vegetation. The support of understory vegetation growth on ant mounds cast shadows on the nests and disrupted nest thermoregulation. Additionally, the bark beetle attack may have been associated with a loss of food resources for wood ants. Our results showed that early (small-scale) management intervention against the spread of bark beetles is the preferred method for maintaining the ant population in conifer forests prone to bark beetle attacks.

Efficacy of synthetic lures for pine bark beetle monitoring | Miloš Knížek, Jan Liška, Adam Véle | Agricultural Journals