Brothers smell similar: variation in the sex pheromone of male European Beewolves Philanthus triangulum F. (Hymenoptera: Crabronidae) and its implications for inbreeding avoidance

Female choice is thought to increase the fitness returns of females. The complementary choice model states that the best mate depends on the particular genotype of a female. Aculeate Hymenoptera represent a special case of complementary female choice because males should be chosen on the basis of their allele at the sex determination locus. The prevalent sex determination mechanism in bees and wasps (single-locus complementary sex determination) requires that, to produce a daughter, diploid offspring are heterozygous at the sex determination locus. Otherwise, infertile diploid males result. Inevitably, the proportion of diploid males increases with the rate of inbreeding. In the European Beewolf, males scent mark territories to attract mates and the composition of the pheromone might provide a basis for female choice. One crucial prerequisite for females to be able to discriminate against brothers and avoid inbreeding is that the male sex pheromone varies with familial affiliation. This hypothesis was tested by analysing the pheromone of male progeny of eight mothers using gas chromatography and mass spectrometry. A significantly higher similarity was found among brothers than among unrelated individuals. Such a genetic component of a male sex pheromone has not yet been described from aculeate Hymenoptera.  © 2006 The Linnean Society of London, Biological Journal of the Linnean Society , 2006, 89 , 433–442.     

Physiological Effects of Heavy Metals on the Moss Rhytidiadelphus squarrosus

Experiments on the effect of Cd, Cu, Ni, Pb and Zn, suppliedas single salt solutions between 10 µM and 0·1M, on the moss Rhytidiadelphus squarrosus showed little alterationto respiratory rates but reduced photosynthetic rates, and somemembrane damage as assessed by K leakage. Two distinct morphologicalforms of the moss showed different responses to supplied heavymetal. Storage of material, after 30 mins exposure to heavymetals, resulted in a further decrease in the photosyntheticrate. Expressing the photosynthetic decline relative to thetotal heavy metal recovered from the moss showed a similar pattern.Transfer of metal from extracellular exchange sites into theprotoplast was also demonstrated with storage after exposure.An approximately linear relationship was demonstrated betweenphotosynthetic decline and intracellular heavy-metal concentration,irrespective of the duration of exposure or morphological natureof the material used. Photosynthetic decline on storage is concludedto be a response to additional metal stress rather than a progressivedeterioration of the physiological process. Cadmium, copper, lead, nickel, zinc, photosynthesis, respiration, membrane damage, intracellular metals, Rhytidiadelphus squarrosus (Hedw.) Warnst     

THE LIMPET PATELLOIDA NIGROSULCATA ON INTERTIDAL PLATFORMS IN THE PERTH AREA, WESTERN AUSTRALIA

Patelloida nigrosulcata on intertidal platforms in the Perthmetropolitan area live on the backs of shells of living abalone,Haliotis roei. Over 95% of abalone 30 mm have one or more limpets,and there is a close relationship between abalone and limpetdensity. Sexes are usually separate in P. nigrosulcata, butabout 4% of the population in hermaphroditic. The animals spawntwice annually in winter (May–June) and spring (October–November).The reproductive periodicity of P. nigrosulata is compared toother published data on acmaeids. ^*Present address: Australian Institute of Marine Science, PMBNo. 3, Townsville, Queensland 4810, Australia (Received 23 March 1987;     

Energy reserves and metabolic expenditures of monarch butterflies overwintering in southern California

Abstract. 1. Energetic expenditure and predicted requirements for overwintering metabolism were determined for monarch butterflies ( Danaus plexippus L.) in southern California.
2. Fat content of butterflies declined steadily from a maximum of 71% lean dry weight in late November to a minimum of 36% lean dry weight in late January. The energy expenditure measured by fat depletion over a 61 day period from 24 November to 25 January was 26.05 joules per day.
3. Butterflies were generally the same temperature as the air at any time they were inactive, whether they were part of a large cluster or roosting solitarily.
4. Oxygen consumption of butterflies increased in a curvilinear fashion with increasing air temperature. Thus, the predicted metabolic requirements for an inactive butterfly during their quiescent period from late November to late January was 30.32 joules per day.
5. In contrast to the steady depletion of fat reserves during their quiescent period in December and January, low and stable fat levels of butterflies in late February coincide with high levels of flight activity, mating and emigration of females from the colony.
6. Progressive tightening of the energy balance due to increasing nocturnal temperatures from northern to southern California coastal areas may limit the southern distribution and duration of overwintering aggregations.     

The relationship of the genus Schizopera Sars within the family Diosaccidae (Copepoda: Harpacticoida)

A review of Schizopera Sars indicates that four species are so much more primitive in the antenna and leg setation that they should be removed to a new genus, Eoschizopera, which can be considered as a direct and immediate ancestor of Schizopera. A further, new, species is described in this new genus. The relationships within this branch of the family Diosaccidae are discussed and the scheme of family evolution proposed by Lang is modified to include Eoschizopera and other genera not considered by him (Goffinella, Protopsammotopa, Psammotopa, Actopsyllus, Balucopsylla, Schizoperoides). Actopsyllus hartmannorum Kunz is removed to a further new genus- Helmutkunzia.     

Carnivores and carotenoids are associated with adaptive behavioural divergence in a radiation of gall midges

1. Adaptive divergence in sympatry is supposed to be inhibited by the homogenizing role of gene flow. However, studies continue to uncover examples of sympatric divergence. In this study, two divergent phenotypes in a complex of four syntopic gall midge morphotypes [nominally Asteromyia carbonifera Osten Saken, Diptera: Cecidomyiidae: Alycaulini] are characterised. The first is a behavioural phenotype governing within‐host tissue preference and the second is a trait governing accessory‐gland carotenoid quality and quantity. 2. One gall morphotype (crescents) lay most of their eggs on mature tissue whereas the other three gall morphotypes oviposit only on young emerging leaves. Ecological maintenance of this divergent trait appears to be driven by enemy‐reduced space. That is, nearly 40% of the crescent morphotype galls that develop high on the plant are attacked by the egg parasitoid Platygaster solidaginis Ashmed, whereas those low on the plant are relatively protected. 3. All morphotypes contain carotenoids in their accessory glands, but the quality and quantity of these pigments differs significantly between the morphotypes and is positively associated with the probability of parasitism by P. solidaginis. 4. Larval salivary glands also contain carotenoids and the plant hormone abscisic acid, which in plants is synthesized from carotenoid precursors and is involved in regulating plant defences. This hormone may facilitate gall development and influence gall morphology. 5. Ecological fitness trade‐offs between carotenoids, parasitoid attack, and plant resistance may be fostering adaptive divergence in ovipositional phenotypes and sympatric speciation in this complex of gall midge morphotypes.