P. atrata L. is active earlier in the season than the other Silphidae species. Some variations are observed from one National Forest District (= NFD) to an other. In Saône River valley (NFD 214) and Vosges Cristallines (NFD 888), maximal activity was observed in early summer. In Plateau Lorrain (NFD 572), maximal activity was observed earlier in Spring. Saône River Valley and Vosges Cristallines widely differ in their edaphic conditions, so that phenological differences can not be attributed to any climatological cause. All that can be said at present is that these regions altogether form a South-Northward oriented gradient. For the moment, two hypotheses might be suggested: (i) samplings were influenced by year effects; (ii) activity in northern populations starts earlier in the vegetation season.
P. atrata L. adult phenology along a south-northward transect in the investigated area.
Each curve summarizes activity observed in one National Forest District (= NFD), defined by the National Forest Survey (= IFN). NFD's range northward in the following order Vallée de la Saône et affluents (=Saône River Valley) < Vosges cristallines < Plateau Lorrain.
Adults live for several years. In a season, each generation takes part into reproduction. Old females differ from the young ones by the production of a structure, named yellow body, which fills their ovarioles, after they have layed down their eggs[287].
As for other Silphinae species, diet is only partially known. Analyses of beetles δ13C and δ15N suggest, that it should be closer to ground beetles than to Nicrophorinae[17].
Adults and larvae have been observed preying upon snails. Preys are not all identified. Among them is found Fruticicola fruticum O.F. Müller. P. atrata L. climbs on the snail back and applies its salivary secretions. Thus, when the snail retracts into its shell and produces slime, the salivary secretion disolves the slime and snail tissues enabling P. atrata L. to move its way into the shell.
Figure 139E2
Snail attack by P. atrata L.[297].
As for O. thoracicum L., when an animal is endangered tegumentary glands secrete a repellent ammonia solution[287].
P. atrata L. is a forest edge species. From forest edge it can colonize the adjacent biotopes. It was thus observed in Maize crops[127].
It was also observed in peatbogs[5], which is in agreement with palaeontological records, that showed a colonization of mesic tundra in Beringian region.
| Habitat type | Location | Vegetation | |
| Natural openlands | |||
| Heathlands | |||
| Peatbogs | Dauges natural reserve, Limousin, France[5] | ||
| Wetlands | |||
| Artificial openlands | |||
| Gardens | |||
| Croplands | |||
| Crop margins | |||
| Set-aside lands | |||
| Grasslands | |||
| Grazedlands | |||
| Hedgerows | |||
| Orchards | |||
| Urban environment | |||
| Woodlands | |||
| Broadleaves | Białowieża primeval forest, Belarus[762] | ||
| Softwoods | |||
P. atrata L. is a wingless species. Fly muscles are not developped[17]. Therefore this species disperses by terrestrial way only.
P. atrata L. habitat distribution pattern looks like the one observed for Nicrophorus humator Gleditsch. In agreement with bibliographical knowledge, this species restricts to forested areas or at least hedgerows. Considering its absence from anthropogenic habitats, it can be supposed that hedgerows are its only corridor, for dispersing between favorable sites.
Up to now, it has also been missing from moisted habitats and peatbogs. Though these types of sites are not privileged by this species, several results indicate that they are normally inhabited by it. In such sites, snails are usually abundant. P. atrata L. presence in moisted habitats should thus be verified in future samplings.
P. atrata L. highest activity was found in isolated tree groups (B2 zone). These are probably reached from woodlands through hedgerows. The absence of records in forest edges (B1 zone) is a bit surprising at first sight. But in this zone, exposed to touristic perturbations, sampling intensity was much lower and this result is artificial. This is indicated by the results for large clearings (D zone), in which micro conditions are close to those in forest edges. Small clearings (E zone), in which there is no edge effect, are not frequented. This time the species trend for colonizing moisted areas is appearent (F zone), only flooded habitats (G zone) are avoided.
P. atrata L. was found at every sampled elevation, without any significant activity altitudinal variation.