Examining the relatedness of behaviors through experimentation: switching on and off chewing and feeding behaviors in a parasitic wasp

Melittobia digitata (Hymenoptera: Eulophidae) are parasitoids known for their cooperative escape behavior. The initial sequences of this escape chewing behavior have been compared to the initial sequences of their feeding behavior. We sought to experimentally test whether these sequences were interchangeable. We were successful in turning off chewing and turning on feeding in a chewing situation, and turning on chewing and turning off feeding in a feeding context. We discuss the implications of this finding for the origin and evolution of these behaviors, and how experimental tests of key cues can be helpful for understanding the evolution of behavioral patterns.     

Seed Reingestion in Savannah Chimpanzees (<Emphasis Type="Italic">Pan troglodytes verus</Emphasis>) at Fongoli,Senegal

Coprophagy is common in captive primates but has also been reported in the wild. For example, wild apes extract and reingest items from faeces. We term this behavior seed reingestion because the dung matrix is not consumed. We assessed the importance of seed reingestion in a population of savannah chimpanzees at Fongoli, southeastern Senegal, one of the hottest and driest areas of the species’ range, where chimpanzees have a relatively narrow dietary repertoire. We observed habituated chimpanzees on 122 d during 8 mo in 2005 and 2006, employing both focal subject and scan sampling of identified individuals for 1278 h of data collection. Chimpanzees reingested seeds of 2 species: Parkia biglobosa and Adansonia digitata. Both seed species have a hard protective shell, and the embryos are rich in proteins and lipids. Chimpanzees initially ate the fruit matrix pulp and swallowed intact seeds before reingesting and chewing/destroying seeds. Seed reingestion accounted for almost 2% of feeding time. We suggest that at Fongoli this behavior may be an adaptive strategy to maximize food intake, by softening the seed’s shell and making the seed’s content more accessible.     

Prelude to a Kiss: Evidence for Mate Discrimination in the Striped Bark Scorpion, <Emphasis Type="Italic">Centruroides vittatus</Emphasis>

The scorpion, Centruroides vittatus, lives in groups, which may allow females to discriminate among mates. We examine possible female mate discrimination based on the duration of the kiss phase of courtship, during which sperm is transferred, and on the duration of the promenade a deux phase of courtship that precedes sperm transfer. Larger males spent less time during the promenade and more time during the kiss phases of courtship. We discuss the implications of this to sexual selection in scorpions.     

Effects of sex and age of a dioecious tree, <Emphasis Type="Italic">Forchhammeria pallida</Emphasis> (Capparaceae) on the performance of its primary herbivore, <Emphasis Type="Italic">Murgantia varicolor</Emphasis> (Hemiptera: Pentatomidae)

The effects of sex and age of a dioecious tree, Forchhammeria pallida, on the survival and development of a Mexican harlequin bug, Murgantia varicolor, were examined. In the laboratory, bugs reared on fruits or fruits and leaves developed rapidly and had a high rate of survivorship, whereas bugs reared on leaves alone developed slowly after the second instar and died by the fifth instar. Murgantia varicolor showed a preference for leaves from juvenile plants over leaves from mature plants, and bugs reared on leaves from juvenile plants survived significantly longer than those reared on leaves from mature plants. Murgantia varicolor showed no preference for feeding on leaves of mature male versus mature female plants. In the field, M.varicolor occurred on male, female and juvenile plants. Although nymphs were less common on male than female F.pallida, their presence in substantial numbers shows that M.varicolor oviposits on both male and female plants. However, adult M.varicolor were rare on male plants. This result is supported by the inability of nymphs to complete their development on vegetative parts of F.pallida in the laboratory. These observations suggest that dioecy in F.pallida may be disruptive to populations of M.varicolor.     

Dynamical behavior of epidemiological models with nonlinear incidence rates

Epidemiological models with nonlinear incidence rates I ^pS^qshow a much wider range of dynamical behaviors than do those with bilinear incidence rates IS. These behaviors are determined mainly by p and , and secondarily by q. For such models, there may exist multiple attractive basins in phase space; thus whether or not the disease will eventually die out may depend not only upon the parameters, but also upon the initial conditions. In some cases, periodic solutions may appear by Hopf bifurcation at critical parameter values.     

Introgression and species demarcation in western European Leuctra fusca (Linnaeus, 1758) and L. digitata Kempny, 1899 (Plecoptera: Leuctridae)

The compilation of a DNA barcoding library of Norwegian stonefly (Plecoptera) species revealed that Leuctra fusca (Linnaeus, 1758 Linnaeus, C. (1758), Systema naturae Per Regna Tria Naturae: Secundum Classes, Ordines, Genera, Species, Cum Characteribus, Differentiis, Synonymis, Locis. Stockholm: Laurentius Salvius. [Google Scholar]) and Leuctra digitata Kempny, 1899 (Leuctridae) share haplotypes in northernmost Scandinavia. Phylogenetic analyses of the mitochondrial (mt) DNA barcode marker COI and the nuclear marker 28S show that the shared haplotypes must result from the introgression of a L. fusca mitochondrion into a L. digitata population on at least two occasions. Although mt introgression is widespread in animals, this represents the first documented case in Plecoptera. This study also included specimens of L. cf. fusca from the Sierra Nevada massif in Spain, a population previously known as L. carpentieri Despax, 1945. Their mt haplotypes are ca. 13% different from other European L. fusca. However, their 28S alleles are compatible with their morphological identification as L. fusca. In view of the possibility of mt introgression, the taxonomic status of this population remains undecided.     

Contrasting genetic diversity patterns in two sister kelp species co‐distributed along the coast of Brittany,France

We investigated patterns of genetic structure in two sister kelp species to explore how distribution width along the shore, zonation, latitudinal distribution and historical factors contribute to contrasting patterns of genetic diversity. We implemented a hierarchical sampling scheme to compare patterns of genetic diversity and structure in these two kelp species co‐distributed along the coasts of Brittany (France) using a total of 12 microsatellites, nine for Laminaria hyperborea and 11 for Laminaria digitata, of which eight amplified in both species. The genetic diversity and connectivity of L. hyperborea populations were greater than those of L. digitata populations in accordance with the larger cross‐shore distribution width along the coast and the greater depth occupied by L. hyperborea populations in contrast to L. digitata populations. In addition, marginal populations showed reduced genetic diversity and connectivity, which erased isolation‐by‐distance patterns in both species. As L. digitata encounters its southern range limit in southern Brittany (SBr) while L. hyperborea extends down to mid‐Portugal, it was possible to distinguish the effect of habitat continuity from range edge effects. We found that L. digitata did not harbour high regional diversity at its southern edge, as expected in a typical rear edge, suggesting that refuges from the last glacial maximum for L. digitata were probably not located in SBr, but most likely further north. For both species, the highest levels of genetic diversity were found in the Iroise Sea and Morlaix Bay, the two regions in which they are being currently harvested. Preserving genetic diversity of these two foundation species in these areas should, thus, be a priority for the management of this resource in Brittany.     

Osmotic sucrose enhancement of single-cell embryogenesis and transformation efficiency in <Emphasis Type="Italic">Oncidium</Emphasis>

Traditional breeding processes to genetically modify the long reproductive cycle and slow seed maturation of orchids have limits. We developed a more efficient protocol using particle bombardment to produce transgenic plants of Oncidium Sharry Baby OM8 (Orchidaceae). Pretreating protocorm-like bodies (PLBs) with 0.5 M sucrose for 2 h increased single-cell embryogenesis 3- to 4-fold; however, shoot formation was suppressed. In addition, new PLBs were regenerated from the entire sucrose-pretreated PLBs, whereas in untreated PLBs, this occurred only from the bases. Pretreated PLBs were bombarded with pSPFLP containing genes encoding a sweet pepper ferredoxin-like protein (pflp), hygromycin phosphotransferase (hpt) and -glucuronidase (GUS) driven by the cauliflower mosaic virus 35S promoter. Pretreated PLBs showed a 14.8-fold increase in GUS expression over the untreated PLBs 40days after bombardment. The presence of pflp and hpt transgenes in the 40 putatively stably transformed lines that produced 113 clones was confirmed by PCR analysis. Six lines (eight clones) were positive for both pflp and hpt transgenes. In addition, clones derived from these lines were either all positive or all negative for the two transgenes, which suggests homogeneity in pretreated PLBs with more single-cell embryogenesis. Thus, sucrose pretreatment enhanced the regeneration of PLBs, single-cell embryogenesis and efficiency of transformation.     

Movies and TV Influence Tobacco Use in India: Findings from a National Survey

Background

Exposure to mass media may impact the use of tobacco, a major source of illness and death in India. The objective is to test the association of self-reported tobacco smoking and chewing with frequency of use of four types of mass media: newspapers, radio, television, and movies.

Methodology/Principal Findings

We analyzed data from a sex-stratified nationally-representative cross-sectional survey of 123,768 women and 74,068 men in India. All models controlled for wealth, education, caste, occupation, urbanicity, religion, marital status, and age. In fully-adjusted models, monthly cinema attendance is associated with increased smoking among women (relative risk [RR]: 1·55; 95% confidence interval [CI]: 1·04–2·31) and men (RR: 1·17; 95% CI: 1·12–1·23) and increased tobacco chewing among men (RR: 1·15; 95% CI: 1·11–1·20). Daily television and radio use is associated with higher likelihood of tobacco chewing among men and women, while daily newspaper use is related to lower likelihood of tobacco chewing among women.

Conclusion/Significance

In India, exposure to visual mass media may contribute to increased tobacco consumption in men and women, while newspaper use may suppress the use of tobacco chewing in women. Future studies should investigate the role that different types of media content and media play in influencing other health behaviors.     

Occurrence and Linkage Between Secreted Insecticidal Toxins in Natural Isolates of <Emphasis Type="Italic">Bacillus thuringiensis</Emphasis>

Little is known about the occurrence and linkage between secreted insecticidal virulence factors in natural populations of Bacillus thuringiensis (Bt). We carried out a survey of 392 Bt strains isolated from various samples originating from 31 countries. The toxicity profile of the culture supernatants of these strains was determined individually against Anthonomus grandis (Coleoptera) and Spodoptera littoralis (Lepidoptera). We analyzed -exotoxin I production and searched for the genes encoding Vip1–2, Vip3, and Cry1I toxins in 125 of these strains. Our results showed that these insecticidal toxins were widespread in Bt but that their distribution was nonrandom, with significant linkage observed between vip3 and cry1I and between vip1–2 and -exotoxin I. Strains producing significant amounts of -exotoxin I were more frequently isolated from invertebrate samples than from dust, water, soil, or plant samples.     

Mycelial growth of strains of the genera <Emphasis Type="Italic">Suillus</Emphasis> and <Emphasis Type="Italic">Boletinus</Emphasis> in media with a wide range of concentrations of carbon and nitrogen sources

Suillus and Boletinus were studied using Ohta medium. In media with glucose or trehalose, all tested strains grew well. With mannose and cellobiose, strains generally grew well, except for one strain of Suillus. Utilization of dextrin and soluble starch differed with each strain, and that of sucrose and glycerol was low for all strains. Utilization of four amino acids, arginine, glutamic acid, aspartic acid, and alanine, was similar to that of ammonium tartrate for Suillus strains, but mycelial growth with amino acids was clearly lower than with ammonium tartrate for the Boletinus strain. The effect of glucose and ammonium tartrate concentrations for nine strains of the genera Suillus and Boletinus was studied with ranges for glucose of 1–100 and 200g/l, respectively, and for ammonium tartrate of 0.2–5 and 20g/l, respectively. Six strains showed maximal growth at a glucose concentration greater than 25g/l, and one strain showed maximal growth at 70g/l. The results indicate that these fungi are adapted to relatively high concentrations of carbon sources. In general, glucose concentration at mycelial growth maximum decreased as ammonium tartrate concentration increased, and at higher concentrations of glucose, mycelial growth decreased more rapidly in higher concentrations of ammonium tartrate.     

Dwarf pea response to gibberellic acid applied to soil through a drip irrigation system,and gibberellic acid biodegradation in soil

Gibberellic acid (29 or 290 M) injected into drip irrigation lines significantly stimulated internode elongation of dwarf peas, and the 290-M soil treatment produced significantly taller plants than did the 29-M treatment. GA₃ uptake may limit GA-induced internode elongation when GA₃ is applied to soil, in contrast to results obtained for hydroponically grown plants, where uptake initially appeared to exceed the rate of hormone metabolism (andersonet al.). It is likely that biodegradation or chemical inactivation limited the plant-availability of GA₃ in the soil. Degradation of moderate GA₃ concentrations in a moist, aerobic loamy fine sand was nearly complete within five days, indicating that the inefficiency of soil applications may outweight the benefits provided by reducing labor costs associated with foliar-spray applications.     

Population analysis of electrophoretic variation in blood serum albumins of European (<Emphasis Type="Italic">Acipenser ruthenus</Emphasis> Linnaeus) and Siberian (<Emphasis Type="Italic">A. ruthenus marsiglii</Emphasis> Brandt) sterlet

We studied blood serum albumins in European (Acipenser ruthenus L.) and Siberian (A. ruthenus marsiglii Brandt) sterlet using disk electrophoresis in polyacrylamide gel. The albumins were shown to be controlled by three codominant alleles of a single locus (ALB* a, b, c). In European sterlet, all six theoretically possible genotypes were described, one of which (ALB*c/c) occurred extremely rarely (one individual). Siberian sterlet was found to be monomorphic for albumins: all fish examined had the ALB*a/a genotype. There was no correlation between albumin patterns and fish fatness. In a number of samples from the Volga River basin, spatial and temporal differentiation was found and analyzed. The results suggest that construction of hydroelectric stations may provoke massive and prolonged sterlet migrations.Translated from Genetika, Vol. 41, No. 2, 2005, pp. 246–253.Original Russian Text Copyright © 2005 by Kuzmin, Kuzmina.     

On a transcendental equation in the stability analysis of a population growth model

Summary We consider the rate equation n = rn for the density n of a single species population in a constant environment. We assume only that there is a positive constant solution n*, that the rate of increase r depends on the history of n and that r decreases for great n. The stability properties of the solution n* depend on the location of the eigenvalues of the linearized functional differential equation. These eigenvalues are the complex solutions of the equation + _–1 ⁰ exp [a]ds(a) – 0 with >0 and s increasing, s (–1)=0, s (0)=1. We give conditions on a and s which ensure that all eigenvalues have negative real part, or that there are eigenvalues with positive real part. In the case of the simplest smooth function s (s=id+1), we obtain a theorem which describes the distribution of all eigenvalues in the complex plane for every >0.     

Bacteriophage phi 1 as a gene-cloning vector in Bacillus subtilis

Summary We attempted to use Bacillus subtilis phage 1 as a gene-cloning vector since the 1 genome was found to have few cleavage sites upon digestion with several kinds of restriction endonucleases. A 1 stock supplied by J. Ito (University of Arizona, Tucson, USA) consisted of two phages, 1E1 and 1E2, having one and two EcoRI-cleavage sites in their genomes respectively. From the latter isolate a deletion mutant 1E21 was induced to increase the size range of DNA segments to be cloned. It was demonstrated, by in vitro recombination experiments with phage 11 DNA, that 1E21 can be used for cloning EcoRI fragments of various sizes. We analyzed the DNAs of ten 1 clones isolated from independent transfectants and found that six of them carried 11 DNA fragments inserted at either of the two EcoRI-cleavage sites. Some of the hybrid phage DNAs were found to be cleaved with BamHI and HaeIII endonucleases at the 11 DNA portion, whereas the parental 1E21 DNA was insensitive to any of these enzymes. These hybrid phages would therefore be useful vectors for cloning foreign DNA fragments generated by cleavage with BamHI or HaeIII endonucleases.     

Characterization of solute/proton cotransport in plasma membrane vesicles from Ricinus cotyledons,and a comparison with other tissues

Plasma membrane vesicles, purified by aqueous two-phase partitioning, were used to investigate the presence of sugar and amino acid carriers in cotyledons and roots of Ricinus communis L. and in roots of red beet (Beta vulgaris L.). Artificial pH and electrical gradients were generated across the plasma membrane, and [¹⁴C]acetate and [¹⁴C]tetraphenylphosphonium were used to demonstrate the presence of an internal alkaline pH gradient and an internal negative membrane potential, respectively. In Ricinus cotyledons, uptake of sucrose was more strongly inhibited than that of glutamine by p-chloromercuribenzenesulphonic acid, phlorizin and phenylglyoxal. The sucrose transport system showed a high degree of substrate specificity with only the presence of maltose and phenyl--glucoside significantly affecting sucrose uptake; in contrast, the glutamine transport system was inhibited by a number of other amino acids. pH+gD-driven glutamine uptake showed saturation kinetics with a K _m of 0.35 mol · m^–3. Sucrose and glutamine -driven uptake was pH dependent with an optimum in the acidic range (pH 6.25) and a decrease at higher pH values. Vesicles obtained from cotyledons and roots of Ricinus showed different transport properties. In the cotyledons, gDH+gD-driven transport for both sucrose and glutamine were observed at similar levels; however, in the root tissue, pH--driven glutamine transport was the dominant uptake process. Uptake rates for glucose and fructose were low in the cotyledons whereas, in the roots, glucose and sucrose transport were slightly higher than that of fructose. In vesicles from red beet tissue there was a different uptake profile, with evidence of proton-coupled cotransport systems for sucrose and glucose, but lower uptake of glutamine and fructose. The results are discussed in relation to the reported different pathways for loading and unloading of solutes in these tissues.Abbreviations CCCP carbonyl cyanide-m-chlorophyenyl hydrazone - DEPC diethyl pyrocarbonate - NEM N-ethylmaleimide - PCMBS p-chloromercuribenzenesulfonic acid - TPP tetraphenylphosphonium ion - gDH⁺ proton electrochemical potential gradient - membrane potential We would like to thank the SERC(UK) and the Royal Society for financial support.     

Effects of low-efficiency pollinators on plant fitness and floral trait evolution in <Emphasis Type="Italic">Campanula americana</Emphasis> (Campanulaceae)

Floral visitors vary in their pollination efficiency and their preferences for floral traits. If low-efficiency pollinators decrease the amount of pollen available to higher efficiency visitors, then low-efficiency visitors may actually have negative fitness consequences for the plants that they visit. We used experimental arrays in two populations to determine the floral preferences and the fitness effects of low-efficiency (or ugly) pollinators on Campanula americana. These ugly pollinators (halictid bees) preferentially visited flowers with pollen over flowers that had had their pollen removed. C. americana pollen color varies quantitatively from light tan to dark purple, and we found that natural variation in pollen color influenced the magnitude of halictid preferences for flowers with pollen. In general, preferences for flowers with pollen were stronger when the ugly pollinators foraged in arrays of flowers with tan-colored pollen than in arrays with purple-colored pollen. When plants received few visits by efficient Bombus pollinators, visits by ugly pollinators significantly decreased siring success relative to plants where visits by ugly pollinators were prevented. In contrast, ugly pollinators did not influence siring success when higher efficiency pollinators were more abundant. Thus, the relationship between low-efficiency pollinators and the plants that they visit varies from commensalistic to antagonistic depending on the presence of other pollinators in the community. Our findings suggest that the negative fitness effects and floral preferences of low-efficiency or ugly pollinators may contribute to the maintenance of a pollen color polymorphism in C. americana.     

Die Sehfelder der zentralen Ommatidien in den Appositionsaugen von Apis mellifica und Cataglyphis bicolor (Apidae,Formicidae; Hymenoptera)

Experimental equipment has been developed to make possible continuous recordings of intensity distribution curves as a function of angle of incidence of light in single ommatidia of arthropod compound eyes. — As preliminary experiment, the visual fields of ommatidia in Limulus, Apis and Cataglyphis have been ascertained without a light measuring instrument. A point source was moved through the visual field and the angular position of the light source on both sides of the visual field at which the rhabdome in the cut-off eye viewed from proximal turned dark was determined. In the dorsal part of the Limulus eye, the cranio-caudal width of the visual field is 42.6±0.3°. The width of the visual field of central ommatidia in Apis is 6.68±0.14° in the dorsoventral plane and 7.42±0.24° in the cranio-caudal direction, in Cataglyphis 15.5±0.5° and 12.5±0.4° respectively.— Similar Gaussian curves for light and dark adapted ommatidia resulted from the continuous recordings of intensity distribution curves in Apis. The rotatory symmetric curve of the worker bee has a half-width of =2.57°. The standardized curve of amplitude one may be approximated by the function y=exp (-0.41 [degree^–2] ²). In Cataglyphis, the half-width of the intensity distribution curve is =8.8° in the dorso-ventral plane and =6.8° in the cranio-caudal plane. Near the axis, the functions y=exp(-0.04 [degree^–2]²) and y=exp(-0.06 [degree^–2] ²) approximate the standardized curves. — Knowledge of intensity distributions in connection with interommatidial angles allows estimation of contrast transfer and resolving power of the array of the dioptric systems. Correlations with behavioural findings are attempted.

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Mit Unterstützung durch den Schweizerischen National-fonds zur Förderung der wissenschaftlichen Forschung, Kredit Nr. 3.315.70, die Eidgenössische Konstruktionswerkstätte (Thun) sowie die Firmen Philips AG (Zürich) und Wild AG (Heerbrugg).     

Epidemiology of <Emphasis Type="Italic">Helicobacter</Emphasis> Infection in Wild Rodents in the Xinjiang-Uygur Autonomous Region of China

Helicobacter species were detected in the feces of wild rodents captured in Qiemo and Ruoqiang in the Xinjiang-Uygur autonomous region of China by polymerase chain reaction and 16S rRNA partial sequence analysis. Forty-four wild rodents, including one Przewalskis gerbil (Brachiones przewalskii), three Northern three-toed jerboas (Dipus sagitta), one long-eared jerboa (Euchoreutes naso), 34 midday gerbils (Meriones meridianus), two short-tailed bandicoot rats (Nesokia indica) and three great gerbils (Rhombomys opimus), were examined. Epidemiological studies indicated that Helicobacter spp. were detected in all genera tested; that H. hepaticus, H. apodemus, H. canadensis, and H. winghamensis were widespread in wild rodents; and that the dominant Helicobacter species in rodents differed depending not only on the order or genus of the animal but also on the animals habitat. H. bilis, H. pylori, H. rodentium and H. suncus were not detected in any animals. It appears that the wild rodents tested in this study are not a reservoir of H. pylori infection.     

An examination of the population genetics of Laminaria and other brown algae in the laminariales using starch gel electrophoresis

While some investigators have attempted to use isozyme electrophoresis to gain information on the genetics of brown algae, most have reported unsatisfactory results. Through exhaustive screening and modification of sample preparation techniques, gel and tray buffers systems, plus staining recipes, we have developed procedures that consistently provide scorable bands for over 20 enzyme systems in several laminarian algae. We have used our procedures to examine geographically diverse populations of Laminaria saccharina and L. longicruris, as well as L. digitata, L. groenlandica, Agarum cribrosum, Alaria esculenta, Chorda tomentosa, and Macrocystis pyrifera. Overall, these kelp species seem to have an extremely low degree of enzyme solymorphism, both within and between populations. While some rare alleles occurred in several enzyme systems, only 3–5 loci were found to be polymorphic. Our results are consistent with the few reported studies that have used molecular genetic techniques to look at the intraspecific variability of laminarian algae. We suggest that at the species level the Laminariales, and perhaps other groups of brown algae, are genetically extremely conservative as compared to other divisions of plants. We further suggest that isozyme electrophoresis provides a quick and useful tool for algal population genetic studies.