Szymon Konwerski

An initial study of insect succession and carrion decomposition in various forest habitats of Central Europe

At the end of summer and beginning of fall 2005 insect succession and pig carrion decomposition were studied in pine-oak forest, hornbeam-oak forest, and alder forest in Western Poland (Central Europe). Five stages of decomposition were recognized: fresh stage, bloated stage, active decay stage, advanced decay stage, and remains stage. The highest rate of decomposition was observed in the alder forest and the lowest in the pine-oak forest. A similar composition of carrion entomofauna was found in each forest. Numerous adults of Lucilia caesar, Phormia regina and Calliphora vomitoria (Calliphoridae), Hydrotaea spp. (Muscidae), Stearibia nigriceps and Parapiophila vulgaris (Piophilidae), Necrodes littoralis and Thanatophilus rugosus (Silphidae), Creophilus maxillosus, Omalium rivulare, Oxypoda acuminata and Philonthus spp. (Staphylinidae) as well as larvae of L. caesar, P. regina, C. vomitoria, Fannidae (Diptera) and N. littoralis, C. maxillosus, Philonthus (Coleoptera) were collected. There were no differences between forests in the sequence of insect occurrence on carrion. However, differences between forests in occurrence time and activity period of some taxa were found. Implications of these results for forensic entomology are discussed.

Insect succession and carrion decomposition in selected forests of Central Europe. Part 2: Composition and residency patterns of carrion fauna

The insect fauna of pig carcasses was monitored in different seasons and forests of Western Poland (Central Europe). The composition of carrion fauna and selected features of residency in carrion in adults and larvae of particular taxa were analysed. A total of 131 adult and 36 larval necrophilous taxa were collected. Only 51 adult species and 24 larval taxa were minimally abundant (>or=10 specimens) at least on one carcass. As for the composition of carrion fauna, there were large differences between seasons, but no important differences between forest types. In most species of Diptera, length of the presence period of adults was between 35 and 65% of the sampling interval, while in most species of Coleoptera, it was above 60%. Only in a few species (e.g., Saprinus semistriatus, Necrodes littoralis or Creophilus maxillosus) was the presence period shorter than 35% of the sampling interval. Interestingly, in some adult Coleoptera (e.g., Necrobia violacea) very long presence periods were recorded. In most taxa, the length of the presence period of larvae was between 40 and 65% of the sampling interval. Only Calliphora vomitoria, Phormia regina, Hydrotaea dentipes, N. littoralis and C. maxillosus had shorter presence periods of larvae. As a rule, residency of adults was broken, whereas residency of larvae was unbroken. Moreover, in adults, two distinct residency patterns were observed; with breaks clumped in the final part of the presence period and with breaks evenly distributed inside the presence period. Almost in all taxa, the time of appearance showed the closest relationship to the onset of bloating. The relationship was significant, positive and strong in adults of P. regina, Fannia manicata, Hydrotaea ignava, Stearibia nigriceps, S. semistriatus, N. littoralis and C. maxillosus as well as larvae of P. regina, H. dentipes, H. ignava, S. nigriceps, N. littoralis, Oiceoptoma thoracicum, Thanatophilus sp., C. maxillosus and Philonthus sp. Interestingly, in some forensically significant taxa (e.g., adults of N. violacea or Thanatophilus rugosus), we found no significant relationship between the time of their appearance and the onset of any decompositional process. Implications for the succession-based post-mortem interval (PMI) estimation, determination of the carcass movement and the season of death are discussed.

Insect succession and carrion decomposition in selected forests of Central Europe. Part 1: Pattern and rate of decomposition

Pig carrion decomposition and insect succession were monitored in different seasons and forests of Central Europe. Pattern of decomposition as well as onset, duration and rate of decompositional processes were measured. Pattern of decomposition was the same in almost all cases with putrefaction, active and advanced decay. In the majority of carcasses active decay was driven by larvae of Calliphoridae with a clear seasonal shift in dominant taxa. However, in some spring, alder forest cases active decay was driven by larvae of Necrodes littoralis (Coleoptera: Silphidae). As a rule the mosaic decomposition was observed. In spring a significant delay in onset of all decompositional processes was found. Season significantly affected rate of active decay due to a much higher rate in summer. Decomposition in alder forest proceeded faster than in pine-oak forest and hornbeam-oak forest. Differences between the latter two forests were practically negligible. Implications for forensic entomology are discussed.

The Food Composition of Immature and Non-breeding White Storks in Poland

Abstract The food of immature White Storks (Ciconia ciconia) feeding in meadows in Poland was studied by pellet analysis. The most important food items by numbers were insects, mainly beetles, which constituted 83% of all prey items (N = 5,958 items) and were found in all pellets (N = 163). However, by biomass, 58% of food consisted of small mammals, mainly voles Microtus sp. Insects (22%) and earthworms (11.5%) were secondary resources. Literature on White Stork diet in Europe also showed that voles, insects and earthworms were the dominant food of breeding White Storks. Their roles changed with latitude, habitat, time, as well as method of data analysis. Generally, the diet of non-breeding storks was similar to breeding birds, but more of the prey was obtained in dry habitats.

Necrophilous Staphylininae (Coleoptera: Staphylinidae) as indicators of season of death and corpse relocation

Several case studies confirm that habitat and seasonal preferences of necrophilous insects are the source of valuable information about the season of death or corpse relocation. Rove beetles (Staphylinidae) are common predators found on corpses and subfamily Staphylininae includes species of the largest forensic importance. In order to evaluate usefulness of Staphylininae as indicators of season of death or corpse relocation, a pig carrion experiment was made from April to October in open and forest habitats of Central Europe. Forty species of Staphylininae were collected, with hairy rove beetle (Creophilus maxillosus) being the most abundant. Some species exhibited a clear preference towards particular habitats. It was found that Philonthus lepidus was exclusive to open habitats and therefore may be useful as indicator of corpse relocation from open to forest habitats. Philonthus decorus was the only species found exclusively on carcasses in forests. Clear seasonality was present in nine species. Philonthus lepidus, Bisnius nitidulus, Philonthusconcinnus and Gabrius osseticus were spring-early summer species, while Philonthusspinipes and Ocypus olens were late summer-early fall species. Bisnius fimetarius and Staphylinus erythropterus were spring-summer species. Platydracus stercorarius was summer species. These results indicate that some Staphylininae are good candidates for indicators of season of death or corpse relocation.

Influence of habitat type and natural disturbances on uropodine mite communities (Acari: Mesostigmata: Uropodina) in oak-hornbeam forests in Central Europe

The study presented in the current article was carried out in two selected natural forest reserves in Poland, i.e. Jakubowo and Las Grądowy near Mogilnica in western Wielkopolska (Poland). The material for the analysis contains quantitative soil samples collected in the period 1978–1983 and more recent material from 2005, 2006 and 2011–2013. The major aim of the study was to establish the changes in species composition, frequency and abundance of Uropodina (Acari: Mesostigmata) mite communities in six plots in Jakubowo and Las Grądowy over a long-term period. The results of the analysis clearly show that the core of the examined mite communities consists of the same eurytopic species, whereas the occurrence of rare species with narrower ecological tolerances was probably to a large extent determined by the different microhabitat conditions in each of the examined areas. The most disturbing phenomenon observed during the research period, which lasted for over 36 years, is a considerable decrease in the abundance of Uropodina in ground litter and soil of the two reserves. The changes that have already occurred in the examined mite communities were associated with natural succession in the flora and anthropogenic disturbances in the environment.

Erotylidae (Insecta, Coleoptera) of Poland – problematic taxa, updated keys and new records

Abstract New data concerning the occurrence of pleasing fungus beetles (Coleoptera: Erotylidae) in Poland are given, with a focus on rare and difficult to identify Central European taxa. Cryptophilus cf. integer (Heer) (Cryptophilinae) is reported from the Polish territory for the first time based on adult and larval specimens collected in the Wielkopolska-Kujawy Lowland. Identification problems concerning species of Cryptophilus introduced to Europe are discussed. Triplax carpathica Reitter (Erotylinae) is recorded from the Białowieża Primeval Forest, which is the first known non-Carpathian finding of this species, located in the close proximity of the Polish-Belarussian UNESCO World Heritage Site “Białowieża Forest”. Discussion of Triplax carpathica being conspecific with Siberian Triplax rufiventris Gebler is provided. New Polish localities of several other Erotylidae are reported, and an updated key to Central European species of Triplax is given. The Triplax key is supplemented with dorsal and ventral habitus images of all treated Triplax species. One of the rarest Central European erotyline species Combocerus glaber (Schaller) is recorded from xerothermic grasslands in North-West Poland.

Nests of the harvest mouse (Micromys minutus) as habitat for invertebrates.

Abstract The nests of the harvest mouse (Micromys minutus) from an extensively used farmland in Western Poland were recognized as a place of occurrence of a large group of invertebrates. In total, from 42 nests 6,544 individuals of invertebrates were extracted. The number of invertebrates was positively correlated with mass of mouse nests. There were found arthropods belonging to the following groups: Arachnida: spiders, mites and pseudoscorpions; Entognatha: springtails; Insecta: Coleoptera, Diptera, Hemiptera, Hymenoptera, Lepidoptera, Psocoptera, Siphonaptera and Thysanoptera. The most numerous groups were mites (Acari, 5,800 individuals) and fleas (Siphonaptera, 415 individuals). Among mites Astigmatida, Mesostigmata and Oribatida were identified. One species, Tyrophagus curvipenis (Acari: Astigmatina), was found in Poland for the first time. The study clearly showed that nests of the harvest mouse are often inhabited by invertebrates, and looks like some of them are characteristic to this particular kind of habitat.

Monochamus sartor (Coleoptera: Cerambycidae) contributes to alpha diversity of Uropodina mites (Acari: Mesostigmata) in first stage of wood decay in Białowieża Primeval Forest

ABSTRACT During the process of slow decay, dead wood is colonized by a diverse group of invertebrates. Pioneer communities of insects are composed of representatives of two families of beetles: Cerambycidae and Curculionidae, which may be carriers for mites. In this paper, we check which species of mites are carried by Monochamus sartor (Fabricius, 1787) in the largest natural forest complex in the North European Plain – The Białowieża Primeval Forest. Individuals of the species were collected in June and July 2012 with 64 intercept traps. In the context of the previous studies on phoresy of mites on the bark beetle Ips typographus (Linnaeus, 1978) in Białowieża Primeval Forest, we conclude that the process of colonization of decaying wood by diverse species of insects entails increase in mite species diversity in this habitat (merocenosis). Our research indicates that mites travel on elytra and pronota of M. sartor; however, dimensions (width and length) of these parts of body as well as the sex of the beetle are not significant for phoretic deutonymphs.

Repeatability of the phoretic relationships between mites of the genus Trichouropoda Berlese (Parasitiformes: Uropodina) and longhorn beetles of the genus Tetropium Kirby (Coleoptera: Cerambycidae) in Białowieża Primeval Forest, Central Europe

ABSTRACT We studied repeatability of phoretic relationships between Trichouropoda shcherbakae Hirschmann, 1972 and longhorn beetles Tetropium castaneum (Linnaeus, 1758) and Te. fuscum (Fabricius, 1787) in Białowieża Primeval Forest in Central Europe. Samples of mites phoretic on two Tetropium Kirby, 1837 species were collected in 2008 and compared with the data from 2007. In both years, the same study plots and collecting methods were used in the same phenological periods. The phenomenon of phoresy was studied with emphasis on phoront–host associations, temporal changes in intensity of phoresy, proportion of carriers of mites in longhorn beetle populations, participation of longhorn beetle species in the transportation of mites, and preferences of phoretic deutonymphs for specific parts of the host’s body. The phoretic relationships are characterized by high repeatability in most of the variables we studied. This is indicative of high stability of the phoretic relationship, probably resulting from the long-term coevolution of beetle dispersants and phoretic mites in a natural forest ecosystem, as well as high specificity typical among pioneer species in initial stages of tree decomposition.