Comb Wax Salvage by the Red Dwarf Honeybee, <Emphasis Type="Italic">Apis florea</Emphasis> F.

Cannibalizing wax from a deserted nest and reusing it in construction of a new nest is only known for absconding colonies of red dwarf honeybee, Apis florea. We tested whether A. florea would preferentially choose to salvage wax from their own, original natal comb over that of other conspecific combs (test 1) and whether they would salvage wax from comb facsimiles of A. florea combs (test 2) fashioned from the combs of A. cerana, A. dorsata, and A. mellifera. In test 1, preferences for natal comb were significantly greater than for non-natal combs. In test 2, no wax was collected from heterospecific combs. It is evident that wax discrimination is context-dependent and that there is considerable genetic variation for the wax-salvaging trait.     

Genetic interactions and dosage effects of Polycomb group genes of Drosophila

The Polycomb (Pc) group of genes are required for maintenance of cell determination in Drosophila melanogaster. At least 11 Pc group genes have been described and there may be up to 40; all are required for normal regulation of homeotic genes, but as a group, their phenotypes are rather diverse. It has been suggested that the products of Pc group genes might be members of a heteromeric complex that acts to regulate the chromatin structure of target loci. We examined the phenotypes of adult flies heterozygous for every pairwise combination of Pc group genes in an attempt to subdivide the Pc group functionally. The results support the idea that Additional sex combs (Asx), Pc, Polycomblike (Pcl), Posterior sex combs (Psc), Sex combs on midleg (Scm), and Sex combs extra (Sce) have similar functions in some imaginal tissues. We show genetic interactions among extra sex combs (esc) and Asx, Enhancer of Pc, Pcl, Enhancer of zeste E(z), and super sex combs and reassess the idea that most Pc group genes function independently of esc. Most duplications of Pc group genes neither exhibit anterior transformations nor suppress the extra sex comb phenotype of Pc group mutations, suggesting that not all Pc group genes behave as predicted by the mass-action model. Surprisingly, duplications of E(z) enhance homeotic phenotypes of esc mutants. Flies with increasing doses of esc ⁺ exhibit anterior transformations, but these are not enhanced by mutations in trithorax group genes. The results are discussed with respect to current models of Pc group function.     

Effects of Polycomb Group Mutations on the Expression of Ultrabithorax in the Drosophila Visceral Mesoderm

The Polycomb group (PcG) genes encode repressors of many developmental regulatory genes including homeotic genes and are known to act by modifying chromatin structure through complex formation. We describe how Ultrabithorax (Ubx) expression is affected by the PcG mutants in the visceral mesoderm. Mutant embryos of the genes extra sex combs (esc), Polycomb (Pc), additional sex combs (Asx) and pleiohomeotic (pho) were examined. In each mutation, Ubx was ectopically expressed outside of their normal domains along the anterior-posterior axis in the visceral mesoderm, which is consistent with the effect of PcG proteins repressing the homeotic genes in other tissues. All of these four PcG mutations exhibit complete or partial lack of midgut constriction. However, two thirds of esc mutant embryos did not show Ubx expression in parasegment 7 (PS7). Even in the embryos showing ectopic Ubx expression, the level of Ubx expression in the PcG mutations was weaker than that in normal embryos. We suggest that in PcG mutations the ectopic Ubx expression is caused by lack of PcG repressor proteins, while the weaker or lack of Ubx expression is due to the repression of Ubx by Abd-B protein which is ectopically expressed in PcG mutations as well.     

Courtship and Mating in the Giant Hairy Desert Scorpion, Hadrurus arizonensis (Scorpionida, Iuridae)

Hadrurus arizonensis is a large, long-lived species of North American desert scorpion with lengthy, stereotyped courtship behaviors that lead to sperm transfer via an external spermatophore. Courtship and mating behaviors in H. arizonensis and other members of the Iuridae family have not been described. H. arizonensis has reproductive behavior similar to that of other scorpions, including the promenade a deux, but with some unique components described here for the first time. Courtship and mating behaviors of H. arizonensis are presented in a flowchart to emphasize its stereotypical nature and suitability for experimental manipulation in field and laboratory studies.     

Confinement Behavior of Cape Honey Bees (Apis mellifera capensis Esch.) in Relation to Population Densities of Small Hive Beetles (Aethina tumida Murray)

We quantified the effects of increasing small hive beetle (Aethina tumida Murray) populations on guarding behavior of Cape honey bees (Apis mellifera capensis, an African subspecies). We found more confinement sites (prisons) at the higher (50 beetles per colony) rather than lower (25 beetles per colony) beetle density. The number of beetles per prison did not change with beetle density. There were more guard bees per beetle during evening than morning. Neither guard bee nor beetle behavior varied with beetle density or over time. Forty-six percent of all beetles were found among the combs at the low beetle density and this increased to 58% at the higher one. In neither instance were beetles causing depredation to host colonies. Within the limits of the experiment, guarding behavior of Cape honey bees is relatively unaffected by increasing beetle density (even if significant proportions of beetles reach the combs).     

Reproductive Isolation Among Geographical Populations of <Emphasis Type="Italic">Drosophila Bipectinata</Emphasis> Duda (Diptera,Drosophilidae) with Recognition of Three Subspecies

Among D. bipectinata Duda, 1923, three subspecies, bipectinata from Southeast Asia (SEA) and Okinawa (OKN), szentivanii stat. nov. from Papua New Guinea (PNG) (Mather & Dobzhansky, 1962) and pacificiae ssp. nov. from South Pacific Ocean (SPO), are recognized. The external morphology of the reproductive organs and the numbers of teeth per row in the sex combs are different between the three subspecies. Furthermore, the sterility of hybrid males between strains from the different regions confirms the subspecies status of each population from SEA, PNG and SPO, together with different gene arrangements in the geographical populations. Although males of the strains from OKN (Okinawa), the northernmost population, show significant differences in the number of teeth of sex combs from males of SEA (Southeast Asia) strains, hybrid males between them are fertile.     

Process of comb division of reused nests in the Australian paper waspRopalidia plebeiana (Hymenoptera,Vespidae)

Summary InRopalidia plebeiana, combs made in the previous year are often reused by foundresses in the following spring and structurally divided into subnests by them. Close observations of the comb dividing process revealed that: 1) combs that had multiple brood areas (areas where cells had eggs) were frequently divided into subnests, while those with single brood areas were never divided; 2) groups of foundresses each occupied a particular brood area even before comb division started; and 3) frequency with which a foundress practiced comb cutting was independent of her social status or oviposition frequency. These observations suggest that the initial grouping of foundresses that colonize an old nest leads to subsequent comb division, rather than the major egg layers cutting combs to safeguard their oviposition territories from their rivals.     

Resolving relationships in some African fungus-growing termites (Termitidae, Macrotermitinae) using molecular phylogeny, morphology, and field parameters

The Macrotermitinae are a large and successful subfamily of fungus-growing termites, characterised by their symbiotic association with white-rot fungi of the genus Termitomyces. The taxonomy of the subfamily, and in particular of the largest genus Odontotermes, is problematic. We used sequences of the mitochondrial 16S gene from termites occurring in East Africa and Malawi to explore the phyletic relationships within the genus Odontotermes and to place the genus in the broader context of other fungus-growing termites. We also interpret this phylogeny in relation to classical morphological taxonomy in the form of absolute and relative dry weights of the sterile castes, and in relation to innate behaviour as shown by nest architecture and fungus comb structure. This work lays the foundations of a complete taxonomic revision of the Macrotermitinae. The phylogeny supports one clear subdivision, here called the “tanganicus” group, within the genus Odontotermes. It also supports the significance of field observations on the structure of fungus combs, as the whole “tanganicus” group builds fungus combs of the sponge type (or modified forms thereof) which are hardly known elsewhere. Other phyletic relationships are less clear, the residual sequences being referred to as the “latericius” group. We recognise three probable miniature species within the “tanganicus” group and another possible one in the residual “latericius group”. Received 16 January 2007; revised 30 October 2007 and 11 March 2008; accepted 4 April 2008.     

The specification of a highly derived arthropod appendage, the Drosophila labial palps, requires the joint action of selectors and signaling pathways

The remarkable diversity of form in arthropods reflects flexible genetic programs deploying many conserved genes. In the insect model Drosophila melanogaster, diversity of form can be observed between serially homologous appendages or when a single appendage is transformed by homeotic mutations, such as the adult labial mouthparts that can present alternative antennal, prothoracic, or maxillary identities. We have examined the roles of the Hox selector genes proboscipedia (pb) and Sex combs reduced (Scr), and the antennal selectors homothorax (hth) and spineless (ss) in labial specification, by tissue-directed mitotic recombination. Whereas loss of pb function transforms labium to prothoracic leg, loss of Scr, hth, or ss functions results in little or no change in labial specification. Results of analysis of single and multiple mutant combinations support a genetic hierarchy in which the homeotic pb gene possesses a primary role. It is surprising to note that while loss of ss activity alone had no detected effect, all mutant combinations lacking both pb and ss yielded the most severe phenotype observed: stunted, apparently tripartite legs that may correspond to a default state. The roles of the four selector genes are functionally linked to a cell nonautonomous mechanism involving the coupled activities of the decapentaplegic (dpp)/TGF-β and wingless (wg)/Wnt signaling pathways. Accordingly, several mutant combinations impaired in dpp signaling were seen to reorient labial-to-leg transformations toward antennal aristae. A crucial aspect of selector function in development and evolution may be in regulating diffusible signals, including those emitted by dpp and wg.     

Characterization of a region of the X chromosome of Drosophila including multi sex combs (mxc), a Polycomb group gene which also functions as a tumour suppressor

Genetic analysis of the 8D3;8D8-9 segment of the Drosophila melanogaster X chromosome has assigned seven complementation groups to this region, three of which are new. A Polycomb group (Pc-G) gene, multi sex combs (mxc), is characterized and mutant alleles are described. Besides common homeotic transformations characteristic of Pc-G mutants that mimic the ectopic gain of function of BX-C and ANT-C genes, mxc mutants show other phenotypes: they zygotically mimic, in males and females, the characteristic lack of germ line seen in progeny of some maternal effect mutants of the so-called posterior group (the grandchildless phenotype). Loss of normal mxc function can promote uncontrolled malignant growth which indicates a possible relationship between Pc-G genes and tumour suppressor genes. We propose that gain-of-function of genes normally repressed by the wild-type mxc product could, in mxc mutants, give rise to an incoherent signal which would be devoid of meaning in normal development. Such a signal could divert somatic and germ line developmental pathways, provoke the loss of cell affinities, but allow or promote growth.     

Le comportement des cirières d'Apis mellifica devant un «thème» de construction. Le role des destructions et des reconstructions des rayons

Summary Some typical shapes of wax-sheet are offered to the bee-workers of a beehive in order to test the «Stigmergy theory» established byGrassé with TermitesCubitermes sp. andBellicositermes natalensis. Is this theory sufficient to explain the building behavior of the Bees?Many similarities are pointed out: the Bees lay some little wax-heaps at random wherever the first comb is built, some of them become the foundations of the first comb; the other combs are not always parallel with the first one and have to be twisted by some bonds of bee-workers; the first phasis of the construction offers an incoherent behavior, the second one is coherent. Certainly, in many exemples, it is possible to see that the achieved building stimulates and leads the bee-workers to construct the next parts of their nest. But, in the bee-world, we will have to apply a complement to the «Stigmergy theory» to explain some facts described in this paper: the remodelling of the cells and the combs by destructions, the twistling of the combs by chains of bees bound with their legs, the construction of irregular cells between male and worker-cells, etc. Finally, the complement of the «Stigmergy theory» for the bee-world will have to take in account the consecutive destructions and contructions of the same part of a comb.     

Energy content,storage substances,and construction and maintenance costs of Mediterranean deciduous leaves

Summary At monthly intervals water content, crude fibre, total and protein nitrogen, sugars, starch, total lipids, ash content and calorific total energy were measured throughout the lifespan of the leaves of the deciduous mediterranean shrubs Pistacia terebinthus L. and Cotinus coggygria Scop. From these data the construction costs and maintenance costs, as well as the construction costs of non-storage compounds and energy expenditure values were calculated. The latter values were also calculated for the evergreen stemmed shrub Ephedra distachya for reasons of comparison with an evergreen mediterranean species. The water status in the deciduous leaves is stable for a long time during the drought period until the beginning of senescence in August/September. In Cotinus an early and considerable increase of storage compounds is found, whilst in Pistacia terebinthus the accumulation is more uniform until August. The N-content is rather low compared with other deciduous leaves, the calorific energy is in the lower range of the values reported for similar species. The construction costs of the leaves of both deciduous species are significantly lower than those calculated by Williams et al. (1987) for two drought deciduous chaparral species but are in agreement with the data reported by other authors on deciduous leaves. Contrary to the findings of Williams et al. they are lower than those of evergreen species; this is also true when the construction cost of the non-storage compounds alone is considered. The values found for Ephedra are similar to the maintenance costs do not show a significant variation in the deciduous leaves. They are higher than those known for evergreen leaves but somewhat lower than the values calculated for deciduous chaparral leaves.     

Individual Effects of Seasonal Changes,Visitor Density,and Concurrent Bear Behavior on Stereotypical Behaviors in Captive Polar Bears (Ursus maritimus)

Stereotypical behaviors in captive polar bears (Ursus maritimus) can be detrimental to their welfare. These behaviors can be reduced through enrichment programs but are often not completely eliminated, so identifying potential triggers is important. The present study investigated the influences of seasonal changes, visitor density, and concurrent bear activity on stereotypical behaviors exhibited by 3 captive polar bears at the Toronto Zoo. All bears exhibited these behaviors; however, individual differences were found in duration and form. The male exhibited less stereotypical behavior during spring, and the females exhibited less stereotypical behavior during winter. An increase in visitor density was associated with more stereotypical behavior in 1 female but less stereotypical behavior in the other 2 bears. All bears engaged in more stereotypical behaviors when the other bears were inactive, and 1 female engaged in more stereotypical behaviors when the other bears were out of sight. Further, when conspecifics were active, all bears engaged in less stereotypical behaviors. Given the variability among individual bears, future enrichment programs must be tailored to the needs of individuals to maximize efficacy.     

<Emphasis Type="Italic">tantalus</Emphasis>, a potential link between <Emphasis Type="Italic">Notch</Emphasis> signalling and chromatin-remodelling complexes

The tantalus (tan) gene encodes a protein that interacts specifically with the Polycomb/trithorax group protein Additional sex combs (ASX). Both loss-of-function and gain-of-function mutations in tan cause tissue-specific defects in the eyes, wing veins and bristles of adult flies. As these defects are also typical for components of the Notch (N) signalling pathway, we wished to determine if TAN interacts with this pathway. Through careful examination of ectopic tan phenotypes, we find that TAN specifically disrupts all three major processes associated with the N signalling pathway (boundary formation, lateral inhibition, and lineage decisions). Furthermore, ectopic tan expression abolishes expression of two N target genes, wingless (wg) and cut, at the dorsal-ventral boundary of the wing. An interaction between tan and N was also observed using a genetic assay that previously detected interactions between tan and Asx. The previously observed ability of TAN to move between the cytoplasm and nucleus, and to associate with DNA, provides a potential mechanism for TAN to respond to N signalling.Edited by P. Simpson     

Flight potential of <Emphasis Type="Italic">Microplitis mediator</Emphasis>, a parasitoid of various lepidopteran pests

The efficacy of using natural enemies to control pests under field conditions largely depends on their mobility and, more specifically, on their capacity to quickly locate pest infestation. For many natural enemies, for example parasitoids, mobility is directly related to flight aptitude, which is determined by the capacity and inclination of a species to engage in flight. In this study, we determined the various factors that affected flight performance of Microplitis mediator (Haliday) (Hymenoptera: Braconidae), using a computer-monitored flight mill. No differences were found in flight performance (i.e., flight distance, duration, speed) between both sexes of M. mediator, and flight capacity increased up to an age of 5–7 days followed by a gradual decline afterwards. For one-day-old female parasitoids, mean (±SE) flight distance and duration were 6.23 ± 0.88 km and 85.15 ± 14.44 min, respectively, with a maximum flight distance of 18.0 km. For male parasitoids, mean flight distance and duration were 5.27 ± 0.51 km and 85.74 ± 7.63 min, respectively. Mating status did not affect flight performance of males, while flight distance of four-day-old ovipositing M. mediator females was much lower than that of un-mated females of the same age. Un-mated adults flew most actively at 22–24°C and inclination to fly gradually declined with decreasing temperature. Temperatures above 26°C considerably reduced flight activity of M. mediator. Wasps engaged in normal flight under a broad range of relative humidity (RH) conditions, with an optimum RH range identified as 75–90%. Our research shows that M. mediator is a highly active parasitoid, because both sexes show great inclination to fly under a range of environmental conditions and flight capacity at different ages. Our results can help explain parasitoid performance in the field and provide baseline information to help guide augmentative releases. Handling editor: Dirk Babendreier.     

The mite Varroa jacobsoni does not transmit American foulbrood from infected to healthy colonies

The present study was conducted to determine whether Varroa jacobsoni can transmit American foulbrood (AFB), caused by the bacterium Paenibacillus larvae to healthy colonies by the surface transport of spores. Five two-storey Langstroth colonies of Apis mellifera ligustica were infested by placing a sealed brood comb, with 10% Varroa prevalence, between the central brood combs of each colony. Two months later the colonies were inoculated with P. larvae by adding brood comb pieces with clinical signs of AFB (45±5 scales per colony). After 60 days the brood area was completely uncapped by means of dissecting needles and tweezers, separating the Varroa mites from the larvae and the collected mites were introduced at a rate of 51 per colony into four recipient hives placed in an isolated apiary. Twenty female Varroa specimens were separated at random and observed by SEM. Paenibacillus larvae spores were found on the dorsal shield surface and on idiosomal setae. All colonies died after 4–5 months due to a high incidence of varroosis. No clinical AFB symptoms or P. larvae spores were observed in microscopic preparations. It is concluded that Varroa jacobsoni does not transmit AFB from infected to healthy colonies; it does, however transport P. larvae spores on its surface.     

Die Lage des Chromatophors in Beziehung zur Systematik vonCymbella-Arten (Bacillariophyceae)

InCymbella the position of the chromatophore corresponds to the taxonomic differentiation into sections. The pyrenoid always shows the same right hand — left hand inclination.

     

Histamine H<Subscript>3</Subscript> Receptor Agonists Decrease Hypothalamic Histamine Levels and Increase Stereotypical Biting in Mice Challenged with Methamphetamine

The effects of the histamine H₃ receptor agonists (R)-α-methylhistamine, imetit and immepip on methamphetamine (METH)-induced stereotypical behavior were examined in mice. The administration of METH (10 mg/kg, i.p.) to male ddY mice induced behaviors including persistent locomotion and stereotypical behaviors, which were classified into four categories: stereotypical head-bobbing (1.9%), circling (1.7%), sniffing (14.3%), and biting (82.1%). Pretreatment with (R)-α-methylhistamine (3 and 10 mg/kg, i.p.) significantly decreased stereotypical sniffing, but increased stereotypical biting induced by METH, in a dose-dependent manner. This effect of (R)-α-methylhistamine on behavior was mimicked by imetit or immepip (brain-penetrating selective histamine H₃ receptor agonists; 10 mg/kg, i.p. for each drug). Hypothalamic histamine levels 1 h after METH challenge were significantly increased in mice pretreated with saline. These increases in histamine levels were significantly decreased by pretreatment with histamine H₃ receptor agonists, effects which would appear to underlie the shift from METH-induced stereotypical sniffing to biting.     

Microscale Laser Surgery Demonstrates the Grasping Function of the Male Sex Combs in Drosophila melanogaster and Drosophila bipectinata

Male secondary sexual traits of animals are richly diversified in form and complexity, yet there are many species in which their precise function remains unknown. Within the genus Drosophila, species belonging to the melanogaster and obscura species groups have evolved a remarkable variety of sex combs, male‐limited secondary sexual traits located on the tarsi of both front legs. Information concerning sex comb function is minimal or absent, except for D. melanogaster, where previous studies indicate that the sex combs are used for grasping the female prior to copulation. These studies, however, do not unambiguously demonstrate comb function, because it has not been possible to ascribe observed behavioral outcomes of the various comb manipulations to changes in the combs per se. We used microscale laser surgery to manipulate comb size in D. melanogaster and D. bipectinata, and tested the hypothesis that the sex combs function as grasping devices in courtship, making them essential for copulation to ensue. Results of high‐resolution behavioral analysis in small observation arenas demonstrated that in both species in which sex combs were surgically eliminated, males were unable to grasp, mount or copulate. The combless foretarsi of these altered males slipped off the end (D. melanogaster) and sides (D. bipectinata) of the female abdomen when courting males attempted to grasp. In most cases, males whose sex combs were reduced but not completely removed exhibited similar copulation probabilities as surgical control males, a result we demonstrated in observation chambers as well as under more ecologically realistic conditions inside population cages where males and females interacted on the surface of fruit substrates. Thus, the sex combs in D. melanogaster and D. bipectinata are grasping devices, essential for mounting and copulation.