Chemical communication

Communication takes place when two or more individuals interact via signal release and reception. This chapter focuses on chemical communication among arthropods, first, discussing the physical attributes of chemical communication and following up with examples that demonstrate the importance of chemical communication as a mediator of behavioral, ecological and evolutionary processes. In doing so, both the functional (i.e. why) and causal (i.e. how) aspects of chemical communication are considered. The examples are drawn from a broad range of topics, including mating conflict (and resolution), honest signals (e.g. marking pheromones), deceptive signals (e.g. sexual deception by orchids to exploit pollinators) and impacts on population dynamics via non-consumptive impacts (e.g. alarm pheromones of aphids). Finally, most of the examples illustrate the subtle and contextual nature of chemical communication making the case that to understand chemical communication one must understand the chemical communicators and not just the chemical compounds that mediate their inter-individual interactions.

Recognition and identification of species in the Bombus lucorum-complex - A review and outlook

The recognition of cryptic species represents one of the major challenges in current taxonomy and affects our understanding of global diversity. In practice, the process from discovery to acceptance in the scientific community can take an extensive length of time. A prime example is the traditionally difficult taxonomy of the cryptic bumblebee species belonging to the Bombus lucorum-complex. The status of the three European species in the group - Bombus lucorum and the closely related Bombus cryptarum and Bombus magnus - has recently become widely accepted, primarily due to investigations of nucleotide sequences and marking pheromones. In contrast, doubts prevail concerning the validity of species identification based on morphology. As a consequence, our knowledge of the species is muddled in a mire of unreliable and confusing literature data from a large number of authors over the centuries. To clarify this issue, this paper provides a recapitulation of the historical literature and highlights the milestones in the process of species recognition. Further, the possibility of a morphologically based species identification is discussed in the context of new molecular data. Finally, this review outlines the current challenges and provides directions for future issues.

Notes on distribution of Bombus cryptarum (Hymenoptera, Apoidea) in Moravian territory (Czech Republic) and its laboratory rearing

B. cryptarum and B. magnus are among the so-called cryptic species whose identification is very difficult due to high interspecific variability of their morphological characteristics. This greatly limits possibilities for studying their biology, bionomics and ecology. The aim of this research was to contribute to knowledge about distribution of B. cryptarum in Moravia (Czech Republic) and to verify the possibility of its laboratory rearing. During 2006–2009, 26 collections were performed at Moravian localities. Of the 17 specimens that were assigned to B. cryptarum or B. aff. cryptarum based on morphology, the molecular analysis of mtDNA RFLP confirmed the identification of 10 speciemens. The molecular analysis even assigned to B. cryptarum one specimen determined morphologically as B. aff. magnus. Of four queens captured in spring, and while applying a laboratory method used for breeding of B. terrestris, two complete nests were successfully reared, including queens of the 2nd generation that then set up their own brood. Species identification of these queens as B. cryptarum was confirmed by both molecular analysis and analysis of the marking pheromones of males among their offspring. A single B. terrestris worker was able to raise young queens of B. cryptarum of the brood.