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The nests of mound-building ants are unexplored reservoirs of fungal diversity. A previous assessment of this diversity in the nests of Formica ulkei suggested that water availability may be a determinant of the composition of this mycota. To investigate this question, we recovered 3594 isolates of filamentous Ascomycota from the nests of Formica obscuripes and adjacent, non-nest sites, employing Dichloran Rose Bengal agar (DRBA), Dichloran Rose Bengal agar containing glycerol (DRBAG), and malt extract agar containing sucrose (MEA20S). Higher numbers of fungi were isolated from the tops of mounds than from within mounds and non-mound sites. Mound nest soils were dominated by members of the family Aspergillaceae, and up to 50% of the colonies isolated on DRBAG belonged to the genus Aspergillus. Pseudogymnoascus pannorum and species of Talaromyces were also present in higher numbers in mound soils. Species of Penicillium were more abundant in non-nest soils, where they accounted for over 66% of isolates on DRBA. All Aspergillaceae assessed for xerotolerance on a medium augmented with glycerol or sucrose were xerophilic. These results, and our observation that the nests of F. obscuripes are low-water environments, indicate that water availability influences the structure of the fungal communities in these animal-modified habitats. [ABSTRACT FROM AUTHOR]

Conducting a repeat study of the presence of mound-building red wood ants (Formica rufa group) after a period of 30 years has rarely been done in Europe. From 1990 to 2020 such a study was done in an intensively used agricultural landscape with fragments of forest in the South-Eastern part of The Netherlands. In 1990, 280 nest mounds of three species of red wood ants and a hybrid were found in the forests and along forest edges. The highest occupancy was in forests of > 25 ha. The connectivity between the forest fragments mainly determined their presence. In 2020, only 160 nest mounds were found. The development of the colonies differed for Formica polyctena Förster, 1850 (slight decrease), F. rufa Linnaeus, 1761 (substantial increase) and F. pratensis Retzius, 1783 (strong decrease). The differences between the species in this highly fragmented landscape may be due to differences in their colonization strategies of either nest splitting or producing swarms of young queens. Furthermore, the analyses show that the type of environment (in a forest or along a forest edge) determines the probability of extinction or settlement. There is a need to undertake management measures to prevent the extinction of species of red wood ants in the area studied. These measures include creating small clearings in dense forests, reducing shading due to overgrowing shrubs or herbaceous plants, and creating buffer zones around intensively manured fields. More long-term monitoring is needed in Europe to compare the circumstances in different regions, detect trends and evaluate the effects of protection measures. [ABSTRACT FROM AUTHOR]

Assessing the influence of new, reduced-risk insecticides on natural enemies within agroecosystems is essential to developing integrated pest management strategies. Three species of mound-building Formica ants are abundant throughout Maine lowbush blueberry fields (Formica exsectoides Forel, F. glacialis Wheeler, and F. ulkei Emery). All three species have been described in the literature as predaceous, with research demonstrating that F. exsectoides preys on major pest insects of lowbush blueberry. The objectives of this study were to determine the impact of common-use and newly introduced insecticides on Formica sp. ant communities in lowbush blueberry fields. Laboratory assays indicated that the commonly applied insecticide phosmet is toxic to F. exsectoides, even after 8 d of field weathering (P < 0.05). Species comparisons indicated that susceptibility varied with exposure to residues in the field. However, some of the reduced-risk biorational insecticides, such as acetamiprid, had little effect on survival of all three species. Abundance of each species in the field varied with lowbush blueberry pesticide-use strategy and amount of nonblueberry vegetation. Both F. exsectoides and F. glacialis were most abundant in organic fields; however, overall F. glacialis was the most abundant in fields of all management types. Field surveys support laboratory results suggesting that phosmet is highly toxic to these species and influences their spatial pattern. Manip-ulation of the crop to conserve natural enemies in lowbush blueberry is difficult because the crop is not planted; therefore, we must look closely at the incorporation of low toxicity insecticides with natural enemies to efficiently control pest insects. [ABSTRACT FROM AUTHOR]

Moles are fossorial mammals that can act both as zoogeomorphic agents and species diversity drivers. These popular animals regularly push heaps of earth from their subterranean tunnel systems to the surface. Thereby they rearrange and improve the local microtopography for ant nesting. Here we use a strongly molehill ( Talpa europaea) mediated nest system of the unicolonial wood ant Formica ( Coptoformica) exsecta to test for ecological factors influencing nest-site selection at the microhabitat scale. Our results show that the size of molehills plays an important role in the multifactorial process of the ant’s nest-site choice with solar insolation as a paramount factor. The ants clearly favored larger and better sun-exposed molehills, suggesting that the coaction of a zoogeomorphic modified microrelief and solar insolation can drive the spatial colonization of F. exsecta. [ABSTRACT FROM AUTHOR]