Alarm Pheromones and Chemical Communication in Nymphs of the Tropical Bed Bug Cimex hemipterus (Hemiptera: Cimicidae)

The recent resurge of bed bug infestations (Cimex spp.; Cimicidae) and their resistance to commonly used pesticides calls for alternative methods of control. Pheromones play an important role in environmentally sustainable methods for the management of many pest insects and may therefore be applicable for the control of bed bugs. The tropical bed bug, Cimex hemipterus, is a temporary ectoparasite on humans and causes severe discomfort. Compared to the common bed bug, Cimex lectularius, little is known about the chemical signalling and pheromone-based behaviour of the tropical species. Here, we show that the antennal morphology and volatile emission of C. hemipterus closely resembles those of C. lectularius and we test their behavioural responses to conspecific odour emissions. Two major volatiles are emitted by male, female and nymph C. hemipterus under stress, (E)-2-hexenal and (E)-2-octenal. Notably, nymph emissions show contrasting ratios of these compounds to adults and are further characterized by the addition of 4-oxo-(E)-2-hexenal and 4-oxo-(E)-2-octenal. The discovery of this nymph pheromone in C. hemipterus is potentially the cause of a repellent effect observed in the bio-tests, where nymph odours induce a significantly stronger repellent reaction in conspecifics than adult odours. Our results suggest that pheromone-based pest control methods developed for C. lectularius could be applicable to C. hemipterus, with the unique nymph blend showing promising practical properties

Why governments intervene: Exploring mixed motives for public policies on corporate social responsibility

Why are national governments increasingly adopting policies on corporate social responsibility (CSR)? Government CSR policies have been explained either as a means of substituting or supporting (mirroring) domestic political-economic institutions and policies, or as a means for government to promote international competitiveness of domestic businesses. Both sets of explanations see governments as driving CSR policies to meet particular national government goals. Support is found for the thesis that CSR policies are often related to international competitiveness, yet our findings suggest that government goals in this regard are not necessarily pre-defined

Mapping of quantitative trait loci for floral scent compounds in cowpea (Vigna unguiculata L.)

Floral scent is a very important trait in plant evolution. Currently, little is known about the inheritance of floral scent in cowpea (Vigna unguiculata L.) or changes that might have occurred during its domestication. Therefore, we analysed scent volatiles and molecular markers in a population of 159 F7 recombinant inbred lines derived from a cross of a domesticated blackeye cowpea cultivar, ‘524B’ and a wild accession ‘219-01’. Using gas chromatography-mass spectrometry (GC–MS) 23 volatile compounds were identified that fall into five general functional categories. Twenty-two of the compounds displayed quantitative variation in the progeny, and a total of 63 QTLs influencing the amounts of these volatiles were mapped onto the cowpea genetic marker map. Although QTLs for volatile compounds putatively involved in cowpea flower scent were found on 9 of the 11 cowpea chromosomes, they were not evenly distributed with QTLs mainly clustered on LGs 1, LGs 2 and LG 4. Our results serve as a starting point for both more detailed analyses of complex scent biosynthetic pathways and the development of markers for marker-assisted breeding of scented rose varieties

Long-distance pollen flow assessment through evaluation of pollinator foraging range suggests transgene escape distances

Foraging range, an important component of bee ecology, is of considerable interest for insect-pollinated plants because it determines the potential for outcrossing among individuals. However, long-distance pollen flow is difficult to assess, especially when the plant also relies on self-pollination. Pollen movement can be estimated indirectly through population genetic data, but complementary data on pollinator flight distances is necessary to validate such estimates. By using radio-tracking of cowpea pollinator return flights, we found that carpenter bees visiting cowpea flowers can forage up to 6 km from their nest. Foraging distances were found to be shorter than the maximum flight range, especially under adverse weather conditions or poor reward levels. From complete flight records in which bees visited wild and domesticated populations, we conclude that bees can mediate gene flow and, in some instances, allow transgene (genetically engineered material) escape over several kilometers. However, most between-flower flights occur within plant patches, while very few occur between plant patches

When Is There a Sustainability Case for CSR? Pathways to Environmental and Social Performance Improvements

This paper was accepted for publication in the journal Business & Society and the definitive published version is available at https://doi.org/10.1177/0007650318755648.Little is known about when corporate social responsibility (CSR) leads to a sustainability case (i.e., to improvements in environmental and social performance). Building on various forms of decoupling, we develop a theoretical framework for examining pathways from institutional pressures through CSR management to sustainability performance. To empirically identify such pathways, we apply fuzzy-set qualitative comparative analysis (fsQCA) to an extensive dataset from 19 large companies. We discover that different pathways are associated with environmental and social performance (non)improvements, and that pathways to success and failure are for the most part not symmetrical. We identify two pathways to improved environmental performance: an exogenous and an endogenous one. We find two pathways to improved social performance that both involve integrating social responsibility into the core business. Pathways to nonimprovements are multiple, suggesting that failure can occur in a number of ways, while there are only a few pathways to sustainability performance improvements