Mating system, mate choice and parental care in a bark beetle.

The cypress bark beetle, Phloeosinus armatus, is a common element of the dying cypress tree system in East-Mediterranean countries. Adult beetles congregate for breeding on this ephemeral resource. We studied three traits that characterize this beetle's sexual behavior and linked them to its reproductive success: mating system, mate choice, and parental care. We found that the females are the 'pioneering sex', excavating the mating chamber. The average female is slightly larger than the male, and female and male body size is correlated, demonstrating size-assortative mating. The time it takes for a male to enter the mating chamber is positively correlated with female size and negatively correlated with its own size, which is perhaps responsible for this assortative mating. Males remain in the gallery during the period of oviposition, gradually leaving soon after the eggs hatch. The number of eggs laid and tunnel length are positively correlated with male body size. Finally, in the presence of both parents, more eggs are laid than when the female alone is present, demonstrating the important contribution of biparental care for reproductive success. We suggest that the interaction between a monogamous mating system, assortative mating, and biparental care contributes to reproductive success.

A comparison between desert and Mediterranean antlion populations: differences in life history and morphology.

We performed a transplant experiment to compare the life histories and morphologies of five geographically representative antlion Myrmeleon hyalinus populations along a sharp climatic gradient, from a Mediterranean climate in Israel's north to a desert climate in the south. Larvae were raised in two environmental chambers simulating Mediterranean and desert climates to investigate the extent to which the different populations exhibit phenotypic plasticity. Along the north-to-south climatic gradient, we observed a gradient in body mass prior to pupation and in pupation rate. Mediterranean populations suffered higher mortality rate when exposed to desert conditions, whereas the mortality rate of desert populations was consistent between Mediterranean and desert conditions. Our results regarding body mass, pupation rate and mortality rate suggest that Mediterranean populations had a more flexible response compared with desert populations. An analysis of digital photographs was used to measure population morphological differences, which were usually indicative of a decrease in trait size along the north-to-south gradient. We show how climatic gradients translate into phenotypic differences in an antlion population and provide a morphometric tool to distinguish between instar stages.

[Pain-sensation following classic neck-dissection (author's transl)]. / Kopfschmerz nach radikaler Neck-dissection.

Resulting neck-dissection surgery (including curative or conservative intervention) very complex pain-syndromes are next to losses of function at the top of complaints stated. The discussion of the case-reports of 242 patients with unilateral neck-dissection and the reexamination of 28 patients free of recurrence revealed several causes of head- and facial pain. The close relationship of functional disability and pain-sensation is discussed. The recommendation of elective neck-dissection - by critical indication - is supported. Resection of nervus accessorius may be necessary in some cases, immediate reconstruction by nerve sutures is recommended. By post-operative treatment the complaints often can be relieved.