Moorland Tipulidae (in particular, the brevi-palp crane-fly, Molophilus ater Meigen) have been studied on the Moor House Nature Reserve, Westmorland. Mean soil temperatures, which were measured by both mercury in steel thermographs and a chemical integration technique using sucrose solutions, showed a reduction of approximately 0.1ºC for every 100' increase in altitude. Between site differences in temperature were about four times greater during the summer and autumn than they were during the winter and spring. The pattern of adult emergence for M.ater was obtained by using emergence traps and a vacuum sampler, and the mean date of emergence was approximately two weeks later at 2700' than at l400'. The middle 68% of the emergence lasted about five days. Field experiments indicated that the site temperature during the spring determined the start of pupation and culture studies suggested a minimum threshold temperature for pupation of 5 to 6 ºC. This threshold is thought to be responsible for both the synchronising of the emergence and the delay in the emergence at higher altitudes. The densities of final instar larvae prior to pupation in the spring varied from approximately 700 to 2000 per sq.m. at different sites. An increase in the mean larval weight at any site, led to an increase in the mean weight of the subsequent female adults and to an increased fecundity, but the mean weight of the males was little changed. Key factor analysis has shown egg and first instar mortality to account for most of the variation in generation mortality from year to year and this is thought to be due to desiccation. Another component within the egg and first instar mortality, thought to be due to predation, is shown, together with reduction in fecundity, to act in a density dependent manner and to contribute to the regulation of population numbers.

No description available.

No description available.

This work was undertaken on an area of moorland in the northern Pennines, between 1954 and 1956. Here 16 species of dung-inhabiting beetles of the genus Aphodlus were found. The adult taxonomy of two closely related species, A. prodromus and A. sphacelatus, was examined in detail and the larval stages of three previously unknown species were identified. The biology of several species was studied, enabling the author to discover some of the factors which separated them ecologically. Attempts were made to assess the place of Aphodlus beetles in the utilisation of sheep dung, and with this end in view the distribution, form and condition of dung on several types of vegetation wore examined. Observations were also made on dung-inhabiting lumbricid worms and dipterous flies which were the other organisms of importance in the utilisation of dung. The worms were most effective in removing dung, but their activities varied on the different types of vegetation. Dipterous larvae were of second importance, and were not appreciably affected by vegetation type. Averaged over the whole year, only one-fifth of the sheep droppings were infested by Aphodius. The beetle infestation was not affected by vegetation type.

No description available.

No description available.

From 1957 to 1960 both field, and laboratory studies were carried out on six British species of woodland harvest- spider, Lacinius ephippiatus (C. L, Koch), Mitopus morio (Fabr.), Nemastoma lugubre (Mull.), Odiellus palpinalis (Herbst), Oligolophus agrestis (Meade) and Oligolophus tridens (C. L. Koch.) The only comparable study is that of Todd (1949, Journal of Animal Ecology, 18, 209-89) whose findings were, in general, restricted to adult harvest- spiders: hence in the present study many of Todd's ideas, were extended to juveniles. Initially a method of determining the various life stages (instars), based on the femur length of the second walking leg, was found for each of the above species Using this information the course of seasonal development of each species was followed in detail: it was also found that, while all instars of L, ephippiatus, N. lugubre. O. palpinalis and O. tridens were exclusively ground dwelling in habit, an extension of range from the ground layer into the shrub layer and tree canopy occurred in the penultimate and final instars of M.. Morio. and O, agrestis. Most of the interstratal movement was restricted to the period between dusk and midnight. To find the cause of the vertical migration these findings were compared with the results of laboratory Studies on temperature and relative humidity preferenda, resistance to dessication and locomotor activity patterns, and with microclimate measurements made in the field. It became clear that, although very closely associated, seasonal migration should be considered separately from diel migration. The former was caused by endogenous factors probably associated with reproduction and not by any change in the physical conditions affecting the various instars. The latter was 'triggered' by the loss of light at dusk, but was not necessarily caused by the increase in the intensity of locomotor activity resulting from this loss.

No description available.

No description available.

This study had two main objectives: to clarify the phylogenetic position of the species cuiTently classified in the genus L igenorhynchus, using a ทานItilocus phylogenetic approach; and to understand the evolutionary history, population structure and phylogeography of L acutus and L. albirostris and the processes that have influenced their distribution in the North Atlantic, using microsatellites and mitochondrial markers.The combined phylogeny analyses performed in this study, using seven nuclear genes and two mitochondrial genes, strongly supports the artificiality of the genus and suggests deep divergences between L. acutus and L albirostris and between these two species and the other members of the genus. Their relationships with members of the subfamily Delphininae were not corroborated, suggesting that these two species possibly deserve to be classified in a new subfamily. The total evidence phylogeny supports previous findings by other authors about the paraphyly of the other four species of the genus Lagenorhynchus, L, obscurus and L, obliquidens are clearly sister taxa, but they do not appear to be closely related to L. australis and L. cruciger, which are more related to Cephalorhynchus lineage; thus this study suggests that these species should probably be assigned to different genera.The time of the most recent common ancestor between L, acutus and L. albirostris was placed during the late Miocene-early Pliocene (〜6.53 MY ago), predating the time of splitting between these two species (〜6Ό^ MY ago). This finding plus the placement of both species at the base of the phylogenetic tree suggest a North Atlantic origin for the ancestor of L. acutus and L. albirostris. In this study, I suggest that the ancestral populations probably migrated toward the North Pacific via the Bering Strait or via the Panamie portal during the Miocene-early Pliocene and that L. obUcjuidens probably diverged and speciated from these ancestral populations.The evolutionary history and population structure of L. acutus and L. albirostris were assessed using a fragment of the control region of the mitochondrial DNA (d loop) of 166 samples for L. acutus and 122 samples for L. albirostris in four geographic areas in the North Atlantic. Both species had moderate haplotypic diversity (0.9170 and 0.7320, respectively) but very low nucleotide diversity (0.0095 and 0.0056, respectively). These findings suggest that populations of both species were affected by historical bottleneck events that reduced their population sizes probably during the Plio-Pleistocene epoch and that their populations are in expansion.When addressing the population division, the Fst values showed a clear differentiation between L. albirostris populations on both sides of the North Atlantic and in the eastern North Atlantic. This study also suggests the existence of one continuous population of L. acutus throughout its geographic range and the presence of one isolated population in the southern North Sea. These results revealed differences in the evolutionary histories of both species, which may be related to preferences in the use of habitat, and dispersion abilities. For example L. acutus is a pelagic species, with preferences for warm temperatures (>12 C) and deep waters, whilst L. alhirosiris is restricted to shallow and coastal areas (<120ทา) and prefers colder waters (<12 C).