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Body size in animals is affected by both genes and the environment (e.g., the amount of food resources). In ants, body size is related to several traits in an individual's physiology and life history. For example, a large queen may increase offspring production, thus increasing her overall fitness. In this study, whether sub-optimal environmental conditions affect the body size of queens of the red wood ant, Formica aquilonia Yarrow (Hymenoptera: Formicidae). The sizes (head width in mm) of virgin queens, i.e., gynes, originating from forest interiors (resource rich) and from commercial forest clear-cuts (resource poor) were measured. No differences in the body size of the queens from the two habitats were found. In addition, the within-nest variation in queen size was similar between habitat types. The results indicate that the body size variation of F. aquilonia queens is not sensitive to environmental variation, unlike F. aquilonia workers. The lack of environmental variation in queen size in F. aquilonia may be due to a strong selection in the past to monomorphic size in this obligately polygynous (multi-queened) species.

Information about the usability of artificial sweeteners, mainly aspartame, for controlling pest ants has spread widely in the internet. With a laboratory experiment we tested the effect of an aspartame based sweetener on the mortality of the black garden ant Lasius niger, a common pest ant in kitchens in Europe. The aspartame-based sweetener was added to the laboratory jelly food of ants in the experimental group (16 colonies). The control group (14 colonies) received otherwise similar jelly but without the aspartame-based sweetener. During the 35 day period of experiment we did not find any signs of aspartame induced mortality in tested ants. In addition, 135 colony founding L. niger queens were submerged in a sweetener solution (artificial sweetener + distilled water) and 135 queens were submerged in distilled water (control). The overall mortality was very low (<1.5%) and no between-group differences in mortality were found within 24 and 96 hours. Our results strongly oppose the rumors that aspartame sweeteners are effective as an ant poison, at least with a typical dose of household aspartame products.

Environmental stress can affect individual development and fitness in insects. Forest logging is a serious environmental stress for forest-specialist insects, such as the mound-building wood ant Formica aquilonia Yarrow 1955, which builds its nests into forests and is dependent on the nutrition provided by the forest habitat. We studied whether the logging causes such a strong environmental stress that it would be visible in disproportionate growth and shape of young winged wood ant gynes (‘queens’) and males. We measured head width, thorax width and wing length of 144 gynes and 100 males from 12 nests from six clear-cut areas, 11 nests from unlogged forest stands and 10 nests in clear-cut—forest margins. We observed disproportionate growth of different body parts and allometric growth of wings in both sexes in areas with different logging-induced disturbance. Gynes had larger heads in clear-cut areas and males had narrowest thoraxes in forest clear-cut edges. With an increasing thorax width, the wing length decreases steeper in clear-cuts than in other habitats in gynes and increases steeper in clear-cuts than other habitats in males. It seems that in a strongly disturbed clear-cut environment, the gynes invest the growth of head width. There seems to be a trade-off between the growth of the thorax and wings in gynes but not in males. The altered body shape may be adaptation to clearings caused by storm events of wild fires, but not forest management practices of modern era. Large-headed gynes may be better in a colony take-over, needed for the establishment of new colonies in early succession stage habitats in this temporally social parasitic species. Long-winged males may have better long-range flight ability, and they may thus have better fitness and change to disperse their genes onto new habitats.