Morpho-functional comparison of the Dufour gland in the female castes of the Amazon ant <Emphasis Type="Italic">Polyergus rufescens</Emphasis> (Hymenoptera,Formicidae)

The Dufour gland is crucially involved in main aspects of the parasite habit of the slave-making ant Polyergus rufescens, i.e. slave-raids and host colony usurpation. Workers use chemicals from this gland as recruitment signals during raid organization, while newly-mated queens use its secretion to appease residents during host nest invasion. Here, we report a comparison of the general morphology and fine structure of the Dufour gland in the female castes of P. rufescens: queens, ergatogynes (intermediate forms), and workers. The analysis clearly shows the link between gland structure and its behavioural role in queens and workers. In particular, queens present a hypertrophied gland with an extended lumen and a thin epithelium no more active in secretory function. This is consistent with the fact that usurper queens use the Dufour gland contents only during the short phase of host nest penetration. Contrary to adult queens, the cytoplasmic organization of the Dufour gland epithelium of raiders is typical for a tissue with secretory activity (abundance of mitochondria, free ribosomes, strands of smooth endoplasmic reticulum and a Golgi apparatus). This is consistent with the continuous raiding activity performed by workers throughout their adult life. The biology of ergatogynes is still an enigmatic matter. Their Dufour gland is intermediate in shape and size between that of queens and workers. It presents a fairly thick epithelium with features that are typical of a quite active secretory tissue.     

Chemical communication in mating behaviour of the slave-making ant <Emphasis Type="Italic">Polyergus rufescens</Emphasis> (Hymenoptera,Formicidae): 3-ethyl-4-methylpentanol as a critical component of the queen sex pheromone

The aim of the research reported here was to determine whether 3-ethyl-4-methylpentanol, a minor but crucial component of the sex pheromone of the North American slave-making ant species Polyergus breviceps, was also a component of the sex pheromone of the European congener Polyergus rufescens. Thus, the contents of mandibular glands of P. rufescens virgin queen were extracted and analysed. The main component of the extracts was methyl 6-methylsalicylate and 3-ethyl-4-methylpentanol was identified as one of several minor components. Further analyses showed that the insects produce mainly the (R)-enantiomer of the alcohol. Males’ responses to various blends of methyl 6-methylsalicylate with the racemate or the pure enantiomers of 3-ethyl-4- methylpentanol were tested in field behavioural bioassays. The data showed that blends of methyl 6- methylsalicylate and 3-ethyl-4-methylpentanol were strongly synergistic, with the most active ratios being biased toward the first component. The addition of other minor components to the binary blend neither increased nor decreased responses by males. Only the (R)-enantiomer of the alcohol was biologically active; its antipode did not inhibit attraction. The results are discussed in terms of the evolution of signals, and are compared with the results previously obtained for the allopatric species Polyergus breviceps. Received 12 November 2007; revised 10 January 2008; accepted 11 January 2008.     

Floral development and systematic position of <Emphasis Type="Italic">Arillastrum</Emphasis>, <Emphasis Type="Italic">Allosyncarpia</Emphasis>, <Emphasis Type="Italic">Stockwellia</Emphasis> and <Emphasis Type="Italic">Eucalyptopsis</Emphasis> (Myrtaceae)

We have investigated the floral ontogeny of Arillastrum, Allosyncarpia, Stockwellia and Eucalyptopsis (of the eucalypt group, Myrtaceae) using scanning electron microscopy and light microscopy. Several critical characters for establishing relationships between these genera and to the eucalypts have been determined. The absence of compound petaline primordia in Arillastrum, Allosyncarpia, Stockwellia and Eucalyptopsis excludes these taxa from the eucalypt clade. Post-anthesis circumscissile abscission of the hypanthium above the ovary in Stockwellia, Eucalyptopsis and Allosyncarpia is evidence that these three taxa form a monophyletic group; undifferentiated perianth parts and elongated fusiform buds are characters that unite Stockwellia and Eucalyptopsis as sister taxa. No floral characters clearly associate Arillastrum with either the eucalypt clade or the clade of Stockwellia, Eucalyptopsis and Allosyncarpia.We gratefully acknowledge Clyde Dunlop and Bob Harwood (Northern Territory Herbarium) for collecting specimens of Allosyncarpia, and Bruce Gray (Atherton) for collecting specimens of Stockwellia. The Australian National Herbarium (CANB) kindly lent herbarium specimens of Eucalyptopsis for examination. This research was supported by a University of Melbourne Research Development Grant to Andrew Drinnan.     

Larval oophagy in the ant <Emphasis Type="Italic">Amblyopone silvestrii</Emphasis> (Hymenoptera,Formicidae)

Summary Larvae pass through five instars in the temperate, subterranean ponerine ant, Amblyopone silvestrii. Field colonies displayed a large decrease in the number of eggs during mid-summer, despite the fact that queens maintained fully developed ovaries with mature eggs. Observations of laboratory colonies indicate that cannibalism by 1st and 2nd instar larvae caused this decrease in egg number. These instars consumed a total of 66–75% of eggs in the nest, with each larva consuming 2–3 eggs before molting to the 3rd instar. At that time the larvae began to feed on arthropods. The preferred prey of A. silvestrii consists of entire centipedes; the large size of these prey items relative to the size of early instar larvae makes it difficult for the larvae to feed on these prey. Additionally, workers of A. silvestrii do not engage in oral trophallaxis. Consequently, oophagy is a plausible method to feed these very small larvae.     

Physiological comparison of copper toxicity in the lichens <Emphasis Type="Italic">Peltigera rufescens</Emphasis> (Weis) Humb. and <Emphasis Type="Italic">Cladina arbuscula</Emphasis> subsp. <Emphasis Type="Italic">mitis</Emphasis> (Sandst.) Ruoss

Peltigera rufescens (Weis) Humb. with a prokaryotic photobiont Nostoc sp. and Cladina arbuscula subsp. mitis (Sandst.) Ruoss with a eukaryotic photobiont Trebouxia sp. were studied to determine the copper sensitivity of lichens with different algal symbionts. Samples growing on historic copper mine-spoil heaps at Ľubietová–Podlipa, Slovakia were assessed for physiological parameters, including total and intracellular uptake of copper, assimilation pigmentation, activity of photosystem II, ergosterol levels, thiobarbituric acid reactive substances and water-soluble protein content. Our results indicate that P. rufescens was more sensitive to copper exposure than C. arbuscula subsp. mitis.     

The <Emphasis Type="Italic">Caenorhabditis</Emphasis><Emphasis Type="Italic">briggsae</Emphasis> genome contains active <Emphasis Type="Italic">CbmaT1</Emphasis> and <Emphasis Type="Italic">Tcb1</Emphasis> transposons

The maT clade of transposons is a group of transposable elements intermediate in sequence and predicted protein structure to mariner and Tc transposons, with a distribution thus far limited to a few invertebrate species. We present evidence, based on searches of publicly available databases, that the nematode Caenorhabditis briggsae has several maT-like transposons, which we have designated as CbmaT elements, dispersed throughout its genome. We also describe two additional transposon sequences that probably share their evolutionary history with the CbmaT transposons. One resembles a fold back variant of a CbmaT element, with long (380-bp) inverted terminal repeats (ITRs) that show a high degree (71%) of identity to CbmaT1. The other, which shares only the 26-bp ITR sequences with one of the CbmaT variants, is present in eight nearly identical copies, but does not have a transposase gene and may therefore be cross mobilised by a CbmaT transposase. Using PCR-based mobility assays, we show that CbmaT1 transposons are capable of excising from the C. briggsae genome. CbmaT1 excised approximately 500 times less frequently than Tcb1 in the reference strain AF16, but both CbmaT1 and Tcb1 excised at extremely high frequencies in the HK105 strain. The HK105 strain also exhibited a high frequency of spontaneous induction of unc-22 mutants, suggesting that it may be a mutator strain of C. briggsae.     

Host nest usurpation and colony foundation in the European amazon ant,Polyergus rufescens Latr. (Hymenoptera: Formicidae)

Summary The socially parasitic mode of founding new colonies by queens of the European amazon antPolyergus rufescens was analysed in the laboratory. Newly-mated females of this obligatory slave-maker were individually introduced into queenright and queenless artificially established colonies of bothFormica cunicularia (the slave present in the natal dulotic nest) andF. rufibarbis (another potentialServiformica host). Particular attention was devoted to the behavioural patterns displayed by these young queens during the usurpation phases. Our observations, supported also by video-taping, show that the slave-making female, before laying her eggs, must penetrate the host colony, kill the resident queen, become accepted by the adult workers and appropriate the host brood. The parasite was almost always adopted in the colonies ofF. cunicularia, whereas in the presence ofF. rufibarbis it was generally killed in a short time. The failure in the attempt of usurping the colonies ofF. rufibarbis is discussed in relation to the host specificity typical of this slave-maker. Finally, egg-laying byPolyergus successful usurpers, the subsequent eclosion of the brood, and its complete social integration in the newly-established mixed colonies were also recorded.     

Phylogenetic analyses of <Emphasis Type="Italic">Uromyces viciae-fabae</Emphasis> and its varieties on <Emphasis Type="Italic">Vicia</Emphasis>, <Emphasis Type="Italic">Lathyrus</Emphasis>, and <Emphasis Type="Italic">Pisum</Emphasis> in Japan

A pea rust fungus, Uromyces viciae-fabae, has been classified into two varieties, var. viciae-fabae and var. orobi, based on differences in urediniospore wall thickness and putative host specificity in Japan. In principal component analyses, morphological features of urediniospores and teliospores of 94 rust specimens from Vicia, Lathyrus, and Pisum did not show definite host-specific morphological groups. In molecular analyses, 23 Uromyces specimens from Vicia, Lathyrus, and Pisum formed a single genetic clade based on D1/D2 and ITS regions. Four isolates of U. viciae-fabae from V. cracca and V. unijuga could infect and sporulate on P. sativum. These results suggest that U. viciae-fabae populations on different host plants are not biologically differentiated into groups that can be recognized as varieties.Contribution no. 184, Laboratory of Plant Parasitic Mycology, Institute of Agriculture and Forestry, University of Tsukuba, Japan     

The ontogenetic basis for floral diversity in <Emphasis Type="Italic">Agonis</Emphasis>, <Emphasis Type="Italic">Leptospermum</Emphasis> and <Emphasis Type="Italic">Kunzea</Emphasis> (Myrtaceae)

Floral development in three species each of Leptospermum and Kunzea, and one species of Agonis, is described and compared. Differences in the number of stamens and their arrangement in the flower at anthesis are determined by the growth dynamics of the bud. In Leptospermum, early expansion of the bud is predominantly in the axial direction and causes the stamen primordia to be initiated in antepetalous chevrons. In Kunzea, early expansion occurs predominantly in the lateral direction and successive iterations of stamen primordia are inserted alternately at more or less the same level. In both genera, further expansion in the lateral plane spreads the stamens into a ring around the hypanthium. Agonis flexuosa is similar to Leptospermum. Other variable factors include the timing at which stamen initiation commences (earlier in Leptospermum than Kunzea), the duration of stamen initiation (hence the total number of stamens produced – varies within genera), and very late differential expansion that forces stamens into secondary antesepalous groups in A. flexuosa and L. myrsinoides.The authors thank Dr H. Toelken for kindly providing some material and the impetus for this project. This research was supported by Australian Research Council grant AS19131815.     

Behavioural Interactions Between <Emphasis Type="Italic">Crematogaster brevispinosa rochai</Emphasis> Forel (Hymenoptera: Formicidae) and Two <Emphasis Type="Italic">Nasutitermes</Emphasis> Species (Isoptera: Termitidae)

In the savanna-like Brazilian biome caatinga, the arboreal and polydomous ant Crematogaster brevispinosa rochai can be found cohabiting with two closely related Nasutitermes species (N. corniger and N. ephratae). This ant occupies variably sized portions of the termite nests and maintains a physical separation with its hosts by plugging the cells of the boundary areas with fibrous material. Although all the analysed cohabiting C. b. rochai nests were queenless, they always contained brood, especially from male and female reproductive castes. Interaction experiments between workers of C. b. rochai and workers or soldiers of N. ephratae revealed a low level of aggressiveness between the two species that contrasts with the aggressiveness of both C. b. rochai and N. ephratae in encounters with other ant (Azteca cf. chartifex, Cephalotes pusillus) or termite (M. cf. indistinctus) species. The association could benefit both ants (additional nesting sites, brood rearing places) and termites (protection against predators, dead ants or ant refuses as source of nitrogen).     

<Emphasis Type="Italic">Agrobacterium</Emphasis>-mediated transformation of Perilla (<Emphasis Type="Italic">Perilla frutescens</Emphasis>)

Agrobacterium tumefaciens-mediated transformation system for perilla (Perilla frutescens Britt) was developed. Agrobacterium strain EHA105 harboring binary vector pBK I containing bar and γ-tmt cassettes or pIG121Hm containing nptII, hpt, and gusA cassettes were used for transformation. Three different types of explant, hypocotyl, cotyledon and leaf, were evaluated for transformation and hypocotyl explants resulted in the highest transformation efficiency with an average of 3.1 and 2.2%, with pBK I and pIG121Hm, respectively. The Perilla spp. displayed genotype-response for transformation. The effective concentrations of selective agents were 2 mg l⁻¹ phosphinothricin (PPT) and 150 mg l⁻¹ kanamycin, respectively, for shoot induction and 1 mg l⁻¹ PPT and 125 mg l⁻¹ kanamycin, respectively, for shoot elongation. The transformation events were confirmed by herbicide Basta spray or histochemical GUS staining of T₀ and T₁ plants. The T-DNA integration and transgene inheritance were confirmed by PCR and Southern blot analysis of random samples of T₀ and T₁ transgenic plants.     

Distribution of similar self-incompatibility (<Emphasis Type="Italic">S</Emphasis>) haplotypes in different genera,<Emphasis Type="Italic"> Raphanus</Emphasis> and<Emphasis Type="Italic"> Brassica</Emphasis>

The nucleotide sequences of ten SP11 and nine SRK alleles in Raphanus sativus were determined, and deduced amino acid sequences were compared with those of Brassica SP11 and SRK. The amino acid sequence identity of class-I SP11s in R. sativus was about 30% on average, the highest being 52.2%, while that of the S domain of class-I SRK was 77.0% on average and ranged from 70.8% to 83.9%. These values were comparable to those of SP11 and SRK in Brassica oleracea and B. rapa. SP11 of R. sativus S-21 was found to be highly similar to SP11 of B. rapa S-9 (89.5% amino acid identity), and SRK of R. sativus S-21 was similar to SRK of B. rapa S-9 (91.0%). SP11 and SRK of R. sativus S-19 were also similar to SP11 and SRK of B. oleracea S-20, respectively. These similarities of both SP11 and SRK alleles between R. sativus and Brassica suggest that these S haplotype pairs originated from the same ancestral S haplotypes.     

Sociality in <Emphasis Type="Italic">Euglossa</Emphasis> (<Emphasis Type="Italic">Euglossa</Emphasis>) <Emphasis Type="Italic">viridissima</Emphasis> Friese (Hymenoptera,Apidae, Euglossini)

Euglossa viridissima is an orchid bee that forms both solitary and multiple female nests, making it a suitable species for the study of factors leading to diverse degrees of sociality in Euglossines. We conducted observations in eight reused nests (where a first generation of bees had been produced) kept in artificial boxes from the Yucatan Peninsula, Mexico. Five nests were reused (reactivated) by a single female (SFN), two nests reused by a mother and one daughter (MFN1) and one nest reused by the mother and two daughters (MFN2). No single nest was reactivated by unrelated females. The number of foraging trips, their duration and the duration of cell provisioning was not different between SFN and MFN. The overall production of cells per female was not different either between both types of nest. However, in MFN although all females did lay eggs, there was a reproductive skew in favor of the mother (95 and 45% of the brood produced in MFN1 and MFN2 respectively). She showed reproductive control of her daughters through oophagy and displaying threatening behavior when the daughters tried to open a cell where she had laid an egg. Brood losses to parasites (Anthrax sp. (Bom-byliidae) and Hoplostelis bivittata (Megachilidae)) were only found in SFN which possibly reflects and advantage of MFN in this respect. Our results coupled with other studies in Euglossa, reveal that a wide range of social behaviors occur in this genus, from solitary and communal to primitive reproductive division of labor. Multiple factors involving different levels of pressure imposed by food availability and parasites may favor such a diverse range of nesting behaviors. Interestingly, female associations in E. viridissima seem a result of kin selection that is enforced by coercion from mother females on their daughters. More studies are needed to shed light upon the social organization of Euglossa and other Euglossines and on their phylogenetic relationships in order to trace the origins of eusociality in Apidae. Received 12 February 2008; revised 25 June 2008; accepted 17 July 2008.     

Social parasitism of <Emphasis Type="Italic">Polistes dominulus</Emphasis> by <Emphasis Type="Italic">Polistes nimphus</Emphasis> (Hymenoptera,Vespidae)

Summary Interspecific facultative social parasitism is well known in ants and in bumble-bees, but it is rarer in wasps. This form of parasitism is traditionally considered to be an intermediate stage in the evolution of obligate interspecific parasitism, where the parasites are no longer able to nest alone. We report field and experimental observations of a newly discovered facultative parasitic relationship between two closely related free-living Polistes species: P. nimphus and P. dominulus. P. nimphus foundresses sometimes usurp the nests of the larger P. dominulus before worker emergence. The invading queen takes over the nest with abundant abdomen stroking on the nest surface and is accepted by workers if they emerge 6 or more days after usurpation. Morphometric comparisons show that the usurper species, though smaller than its victims, has morphological adaptations consisting of larger heads, mandibles and front femora relative to their body size that may give it an advantage during nest invasion. This strategy is likely to be taken only after the foundress loses her original nest because invading P. nimphus queens have lower reproductive success than they would have had on their own nest. Overall, we found that P. nimphus usurpers use strategies of invasion similar to those of two obligate parasites, suggesting that this may be an example of one of the pathways by which social parasitism evolved.Received 4 April 2003; revised 8 August 2003; accepted 14 September 2003.     

Nesting biology of the arboreal fungus-growing ant <Emphasis Type="Italic">Cyphomyrmex cornutus</Emphasis> and behavioral interactions with the social-parasitic ant <Emphasis Type="Italic">Megalomyrmex mondabora</Emphasis>

We describe the extraordinary nesting habits of the fungus-growing ant Cyphomyrmex cornutus (Formicidae, Myrmicinae, Attini) and the natural history of Megalomyrmex mondabora (Formicidae, Myrmicinae, Solenopsidini), a social parasite that inhabits nests of C. cornutus and other small attine ants. The study was carried out at two sites on the Atlantic slope of Costa Rica. The C. cornutus nest is an oblong mass of accreted soil, attached to or suspended from low vegetation in wet forest understory. Less than a fourth of the nest volume has chambers and is inhabited by C. cornutus; the remainder is a semi-solid mass of accreted soil often housing a variety of arthropods, including other unspecialized commensal ant species. Five C. cornutus colonies examined were parasitized by M. mondabora. Colonies of M. mondabora inhabited chambers very near those of the host. In laboratory observations, M. mondabora and C. cornutus workers interacted with little aggression despite the consumption of C. cornutus larvae and fungi by M. mondabora. During most interactions, C. cornutus workers responded submissively, whereas M. mondabora appeared indifferent or nonresponsive. Megalomyrmex mondabora parasitizes several other attine species (Cyphomyrmex costatus, Cyphomyrmex salvini, and Apterostigma goniodes), and it appears therefore a relatively unspecialized social parasite with broad attine hostassociation. The size of M. mondabora workers vary with host species, suggesting M. mondabora sensu lato comprises either cryptic species or the host environment affects worker size. Received 14 September 2006; revised 1 February 2007; accepted 6 February 2007.     

Cloning and expression of <Emphasis Type="Italic">mel</Emphasis> gene from <Emphasis Type="Italic">Bacillus thuringiensis</Emphasis> in <Emphasis Type="Italic">Escherichia coli</Emphasis>

Previous work from our laboratory has shown that most of Bacillus thuringiensis strains possess the ability to produce melanin in the presence of l-tyrosine at elevated temperatures (42 °C). Furthermore, it was shown that the melanin produced by B. thuringiensis was synthesized by the action of tyrosinase, which catalyzed the conversion of l-tyrosine, via l-DOPA, to melanin. In this study, the tyrosinase-encoding gene (mel) from B. thuringiensis 4D11 was cloned using PCR techniques and expressed in Escherichia coli DH5 . A DNA fragment with 1179 bp which contained the intact mel gene in the recombinant plasmid pGEM1179 imparted the ability to synthesize melanin to the E. coli recipient strain. The nucleotide sequence of this DNA fragment revealed an open reading frame of 744 bp, encoding a protein of 248 amino acids. The novel mel gene from B.thuringiensis expressed in E. coli DH5 conferred UV protection on the recipient strain.     

<Emphasis Type="Italic">Phuphanochloa,</Emphasis> a new bamboo genus (<Emphasis Type="Italic">Poaceae</Emphasis>: <Emphasis Type="Italic">Bambusoideae</Emphasis>) from Thailand

Summary  A new monotypic bamboo genus Phuphanochloa (Poaceae: Bambusoideae) from north-eastern Thailand is described, together with a new species, P. speciosa.     

<Emphasis Type="Italic">Mycobacterium avium</Emphasis> disease in wild red-legged partridges (<Emphasis Type="Italic">Alectoris rufa</Emphasis>)

Three wild red-legged partridges (Alectoris rufa) from intensively managed hunting areas in Spain were received for necropsy. They showed granulomatous lesions in different parts of the body, mainly in liver and spleen. Microscope examination of the granulomas showed central caseous necrosis and large amounts of acid-fast bacilli, surrounded by epitheloid cells, giant cells, and lymphocytes. Attempts to isolate and culture the bacillus in Colestsos medium were unsuccessful, but the polymerase chain reaction technique revealed the presence of microorganisms belonging to the Mycobacterium avium complex in one of the partridges. This is the first report of avian tuberculosis in free-living red-legged partridges.     

Detection of <Emphasis Type="Italic">Candida</Emphasis><Emphasis Type="Italic">dubliniensis</Emphasis> in Venezuela

Over the past decades there has been a significant increase in fungal infections caused by Candida species, and continues to be common in immunocompromised individuals infected with the human immunodeficiency virus (HIV). Although Candida albicans remains the fungal species most frequently isolated as an opportunistic oral pathogen, other non-albicans are often identified in this cohort of patients, including C. dubliniensis. This yeast is closely related to and shares many phenotypic characteristics with C. albicans. Colonies of these two species appear morphologically identical when not grown on special media. The shared phenotypic characteristics of C. dubliniensis and C. albicans suggest that many C. dubliniensis isolates may have been misidentified as C. albicans in the past. The present studies aim is to recover and identify C. dubliniensis, and presumptive clinical C. albicans, from the oral cavities of HIV-seropositive individuals, comparing conventional media to obtain a simple, low-cost and reliable identification system for C. dubliniensis. A total of 16 isolates (3,98%) had been obtained from 402 HIV infected individuals with recurrent oropharyngitis and were identified as C. dubliniensis. Out of these C. dubliniensis isolates 19% were resistant, with MICs above 64 μg/ml to fluconazole. This constitutes, to the authors knowledge the first recovery of this organism in Venezuela.     

Production of interspecific somatic hybrids between tuber mustard (<Emphasis Type="Italic">Brassica</Emphasis><Emphasis Type="Italic">juncea</Emphasis>) and red cabbage (<Emphasis Type="Italic">Brassica oleracea</Emphasis>)

In the present investigation, the interspecific somatic hybridization between tuber mustard and red cabbage was established in order to introduce valuable genes from red cabbage (Brassica oleracea) into Brassica juncea. Prior to fusion treatment, protoplasts of red cabbage were inactivated with 2 mM iodoacetamide to inhibit cell division. Micro-calluses were obtained at a frequency of 10.3% after approximately 5 weeks culture following protoplast fusion. Some of the fusion-derived calluses possessed red pigmented cells after being transferred to proliferation medium, and they were presumably considered to be somatic hybrid cell lines. Plantlets were regenerated from 12 cell lines, of which nine plantlets exhibited characteristics intermediate of both parents in terms of plant morphology. With the exception of common protein bands featured by two parents, there were unique banding patterns produced in the hybrids by using SDS-PAGE analysis. By chromosome countings, it was showed that they ranged approximately from 2n=30 to 42 in chromosome numbers. Their hybridity were further confirmed by RAPD analysis revealing that genes of both parents were partially incorporated into the hybrids. Positively, all these hybrids were capable of seed-setting. The pod-setting was 4.2 in somatic hybrid H₇ when backcrossed with tuber mustard.