Ten years of invasion: Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae) in Britain

1. Harmonia axyridis was first recorded in Britain in 2004. Two subsequent earlier records were received from 2003. 2. The UK Ladybird Survey, a citizen science initiative involving online recording, was launched in 2005 to encourage people across Britain to track the spread of H. axyridis. Tens of thousands of people have provided records of H. axyridis and other species of ladybirds, creating an invaluable dataset for large‐scale and long‐term research. Declines in the distribution of seven (of eight assessed) native species of ladybird have been demonstrated, and correlated with the arrival of H. axyridis, using the records collated through the UK Ladybird Survey. 3. Experimental research and field surveys have also contributed to our understanding of the ecology of H. axyridis and particularly the process of invasion. Harmonia axyridis arrived in Britain through dispersal and introduction events from regions in which it was deliberately released as a biological control agent. The rapid spread of this species has been attributed to its high natural dispersal capability by means of both flight and anthropogenic transport. A number of factors have contributed to the successful establishment and indeed dominance of this polymorphic species within aphidophagous guilds, including high reproductive capacity, intra‐guild predation, eurytopic nature, high resistance to natural enemies within the invaded range, and potentially phenotypic plasticity. 4. The global invasion by H. axyridis and subsequent research on this species has contributed to the general understanding of biological invasions.     

Multi-scale assessment of macroinvertebrate richness and composition in Mediterranean-climate rivers

1. Similar constraints in distant, but climatically comparable, regions may be expected to yield biotic assemblages with similar attributes. Environmental factors that constrain communities at smaller scales, however, may be different between climatically similar regions. Thus, patterns observed at large scales may differ from those detected at small scales, and international comparisons should be focussed at multiple scales. 2. Mediterranean‐climate regions (MCRs) are characterized by remarkable seasonal variability in precipitation and temperature. Accordingly, rivers in these regions have seasonal and predictable floods and droughts, and temporary reaches are frequent. Present in six geographical regions of the world, MCRs have similar environmental constraints and are ideal for testing intercontinental similarities between macroinvertebrate communities. 3. We examined aquatic macroinvertebrate taxon richness and composition in MCRs at three scales: regional, reach and macrohabitat. At the regional scale, the Mediterranean Basin had the highest taxon richness at family level, and southwestern Australia the lowest. Taxonomic composition showed c. 85% similarity between the northern hemisphere MCRs of California and the Mediterranean Basin, which were followed in similarity by South Africa. The two Australian MCRs (South west and South) showed a similarity to each other of about 70% whereas the Chilean fauna was the most distinct. 4. At the reach scale, taxon richness was not significantly different between permanent and temporary reaches in any MCR, whereas taxonomic composition was significantly different among northern hemisphere MCRs. At the macrohabitat scale, taxon richness was not significantly different between lotic and lentic macrohabitats within any of the MCRs, but differences in macroinvertebrate communities were found between macrohabitats when considering regions. 5. Our results show that the strength of similarity between distant but climatically similar regions is scale‐dependent, being highest at the macrohabitat scale. Although the similarities in richness and composition at the macrohabitat scale are presumed to be universal, the seasonal predictability of drought in MCRs is expected to result in characteristic macroinvertebrate responses at the reach scale. We suggest, however, that regional evolutionary history and environmental characteristics may override this general pattern of a similar response of MCRs at different scales. The Mediterranean Basin and California, having similar historical and environmental condition, thus appeared as the most similar MCRs at all scales.     

Costimulation of resting B lymphocytes alters the IL-4-activated IRS2 signaling pathway in a STAT6 independent manner: implications for cell survival and proliferation

INTRODUCTIONThe inappropriate enhancement of lymphocytesurviVal due to a block in programmed cell deathand/or an enhancement of entry into the cell cyclecan contribute to the abnormal expansion of clonesresulting in tumorigenesis or the breakdown of pe-ripheral self-toleranced, 2]. Proper lymphocytehomeostasis is critical for normal immune functionand is maintained by a complex series of cellularinteractions and the action of secreted cytokines.Illterleukin-4 (IL-4), a cytokine produced …     

The Effects of Temperature and Daylength on the Rate of Development of Pigeonpea

Eleven cultivars of pigeonpea, representing five different maturitygroups, were grown under controlled conditions to determinehow the rate of development from sowing to flower bud initiation(FBI) and sowing to flowering was affected by temperature anddaylength, the two environmental variables thought to have mostinfluence on reproductive development. Both temperature and daylength had substantial effects overthe range 16–32 C and 10–14 h respectively. Comparisonswithin the 12 h daylength treatment showed no consistent patternwith mean temperature. A discrete-rate analysis was used todetermine the effect on development of each of the temperaturesmaking up the various treatment combinations of day and nighttemperature. The rate of development from sowing to FBI varied among cultivars.The responses to temperature were all strongly curvilinear withoptima between 20 and 24 C. The rate of development from sowingto flowering showed a similar pattern. The effect of daylengthon the rate of development was the greatest between sowing andFBI, with the greatest sensitivity between 12 and 14 h. For the range of conditions considered, temperature had at leastas great an influence as daylength on the rates of developmentfrom sowing to FBI and from sowing to flowering. Some of theresponses to time of planting that have previously been attributedto daylength effects may, in fact, have been due to temperature.The responses to temperature of reproductive and vegetativedevelopment are very different. Phenology, Cajanus cajan     

The Occurrence and Development of Plasmodium mexicanum in the Western Fence Lizard Sceloporus occidentalis

SYNOPSIS. From various localities in California, 81 (21%) of 381 Sceloporus occidentalis were found infected with Plasmodium mexicanum. Variations in asexual reproduction and host response during the acute period of development are discussed.
Appearance of initial infections in early March and the subsequent increase in natural incidence of the parasite, the absence of infections in hatchlings, and the persistence of numerous gametocytes in hibernating lizards suggest a period of spring transmission.