Ecology of aphidophagous ladybird Propylea species: A review

Herein, the ecology of genus Propylea, with special reference to its three species — viz. P. dissecta (Mulsant), P. japonica (Thunberg), and P. quatuordecimpunctata Linnaeus is reviewed, with an eye toward its position in natural habitats and amongst other ladybirds and its biocontrol potential. Although Propylea is not as polyphagous as other successful species, it evidences a preference for certain prey, specifically aphids and whiteflies. This genus is a good model for studies of mating, reproduction, sexual selection, etc. Propylea is usually an intraguild prey in the guilds containing ladybirds, such as Harmonia axyridis (Pallas) and Coccinella septempunctata L. It also appears that it retains some intrinsic advantages that aid in the sustenance and survival of the species. Owing to its smaller size and level of victimization in the guild, its biocontrol potential is questionable, but its size disadvantages are counter-balanced by its high intrinsic rate of increase, high predation, reproductive potential, and bioconversion efficiency, as well as the ease with which it can be reared in the laboratory. Further research will be necessary to ascertain clearly the biocontrol potential of Propylea.     

Ectoparasitic Acugutturid Nematodes of Adult Lepidoptera

Noctuidonema guyaneme is an interesting ectoparasite of adult Lepidoptera that feeds on hosts from at least five families with its long stylet. Noctuidonema guyanense spends its entire life on the adult moth and is sustained as it is passed from moth to moth during host mating. Overlapping host generations are essential for parasite survival. This nematode occurs throughout tropical and subtropical America and is transported by at least one of its hosts, Spodoptera frugiperda, during migration to northern sites in the United States each spring. Noctuidonema guyanense debilitates its hosts. Research conducted to help determine the biological control importance of this nematode is reviewed. Two additional species, N. daptria and N. dibolia, are now known for Noctuidonema.     

Studies on four new species of the malacocarpic Sargassum (Sargassaceae, Heterokontophyta) in China

In this paper, four new species of malacocarpic Sargassum are described: S. fuliginosoidesTseng et Lu sp. nov. is characterized by its discoid holdfast, the presence of the bulbs on the basal parts of the primary branches and very thick, lanceolate leaves. S. gemmiphorum Tseng et Lu sp. nov. is characterized by its conical holdfast, usually branched axis and very long, narrow, thin, denticulate leaves. S. shandongense Tseng, Zhang et Lu sp. nov. is characterized by its discoid holdfast, flattened primary branches, its leaves mostly entire or wavy at the margins and its racemose to paniculate receptacles. S. qingdaoense Tseng et Lu sp. nov. is characterized by the presence of the glandular dots on the ultimate branches and elongated lanceolate, acute, mostly wavy leaves.     

Mycobacterium tuberculosis Rv3802c Encodes a Phospholipase/Thioesterase and Is Inhibited by the Antimycobacterial Agent Tetrahydrolipstatin

The cell wall of M. tuberculosis is central to its success as a pathogen. Mycolic acids are key components of this cell wall. The genes involved in joining the α and mero mycolates are located in a cluster, beginning with Rv3799c and extending at least until Rv3804c. The role of each enzyme encoded by these five genes is fairly well understood, except for Rv3802c. Rv3802 is one of seven putative cutinases encoded by the genome of M. tuberculosis. In phytopathogens, cutinases hydrolyze the waxy layer of plants, cutin. In a strictly mammalian pathogen, such as M. tuberculosis, it is likely that these proteins perform a different function. Of the seven, we chose to focus on Rv3802c because of its location in a mycolic acid synthesis gene cluster, its putative essentiality, its ubiquitous presence in actinomycetes, and its conservation in the minimal genome of Mycobacterium leprae. We expressed Rv3802 in Escherichia coli and purified the enzymatically active form. We probed its activities and inhibitors characterizing those relevant to its possible role in mycolic acid biosynthesis. In addition to its reported phospholipase A activity, Rv3802 has significant thioesterase activity, and it is inhibited by tetrahydrolipstatin (THL). THL is a described anti-tuberculous compound with an unknown mechanism, but it reportedly targets cell wall synthesis. Taken together, these data circumstantially support a role for Rv3802 in mycolic acid synthesis and, as the cell wall is integral to M. tuberculosis pathogenesis, identification of a novel cell wall enzyme and its inhibition has therapeutic and diagnostic implications.     

From heritability to probability

Can a heritability value tell us something about the weight of genetic versus environmental causes that have acted in the development of a particular individual? Two possible questions arise. Q1: what portion of the phenotype of X is due to its genes and what portion to its environment? Q2: what portion of X’s phenotypic deviation from the mean is a result of its genetic deviation and what portion a result of its environmental deviation? An answer to Q1 provides the full information about X’s development, while an answer to Q2 leaves out a large portion unexplained—that portion which corresponds to the phenotypic mean. Q1 is unanswerable, but I show it is nevertheless legitimate under certain quantitative genetics models. With regard to Q2, opinions in the philosophical and biological literature differ as to its legitimacy. I argue that not only is it legitimate, but in particular, under a few simplifying assumptions, it allows for a quantitative probabilistic answer: for normally distributed quantitative traits with no G-E correlation or statistical G × E interaction, we can assess the probability that X’s genes had a greater effect than its environment on its deviation from the mean population value. This probability is expressed as a function the heritability and the individual’s phenotypic value; we can also provide a quantitative probabilistic answer to Q2 for an arbitrary individual where the probability is a function only of heritability.     

Arthrostemma primaevum (Melastomataceae): A new species endemic to southeastern Mexico

Arthrostemma primaevum, a new species endemic to southeastern Mexico, is described, illustrated, and compared with its closest extant relative,A. ciliatum. The chromosome count ofn=15, reported here forA. primaevum, suggests thatA. ciliatum, withn=30, is a tetraploid derivative with a much broader geographic and elevational range. In addition to its distinctive unlobed staminal appendages and unique chromosome number,A. primaevum is notable for its shorter, urceolate hypanthium and seeds that have essentially smooth continuous semicircular ridges.     

Contributions toward a monograph of cybianthus (Myrsinaceae): I. Subgenus iteoides and the identity of conomorpha loretensis

A provisional key to the species ofCybianthus subgenusIteoides is presented and one new species, C.colombianus, is described, illustrated and discussed.Conomorpha loretensis Lundell is transferred toCybianthus, its relationships within subgenusWeigeltia are discussed, and a key to its sister species,C. gardneri and C.dubius, is provided.     

Ostéologie et affinités de Trematochampsa taqueti (Crocodylia,Mesosuchia) du Sénonien inférieur d'In Beceten (République du Niger)

Among the abundant remains of Mesosuchia that have been yielded by the early Senonian locality of In Beceten (Niger), the most numerous belong to the species Trematochampsa taquetiBuffetaut, 1974. The osteology of this species is described here. This medium-sized crocodilian, with a moderately elongated skull, is characterized, among other features, by its antorbital fenestra, its surangular-quadratojugal articulation, its slightly displaced post-orbital pillar, its teeth with wrinkled enamel, and its amphicoelous vertebrae. In its general outlook, this animal is rather reminiscent of the Goniopholidae, from the Upper Jurassic and the Cretaceous of Laurasia, but it is more primitive than them, and resemblances are probably due to convergence phenomena. The family Trematochampsidae is probably essentially Gondwanian, and could persist until the Senonian thanks to a certain isolation from Laurasia, where more progressive Crocodylia became predominant much earlier than in Africa and South America.     

Effect of double bond geometry in sphingosine base on the antioxidant function of sphingomyelin

We previously showed that sphingomyelin (SM) inhibits peroxidation of phosphatidylcholine (PC) and cholesterol. Since SM uniquely has a trans unsaturation in its sphingosine base, we investigated whether this feature is important for its antioxidant function. Substitution of the natural trans Δ⁴-double bond with a cis double bond (cis-SM), however, increased SM’s ability to inhibit Cu²⁺-mediated 16:0-18:2 PC oxidation by up to eightfold. Dihydro-SM, which lacks the double bond, was equally effective as trans-SM. In contrast to its effect in the sphingosine base, the presence of a cis double bond in the N-acyl group of trans-SM was not protective. cis-SM also inhibited the oxidation of cholesterol by FeSO₄/ascorbate more efficiently than the trans isomer. The enhanced protective effect of cis-SM is selective for metal ion-promoted oxidation, and appears to arise from a decrease in the effective concentration of metal ions. These studies show that the trans double bond of SM is not essential for its antioxidant effects.     

Die GattungTeutonica Schröder 1991 (Gastropoda) aus dem Dogger Deutschlands und Nordwestpolens

Up to now the genusTeutonica has only been known by its type species. Four species and two subspecies are related to it herein; two species and one subspecies are new:T. verrucosa, T. procera andT. gramanni nodosa. Zygopleura rectecostata Walther is based on poorly preserved juvenile shells of aTeutonica species — therefore its specific identity will remain doubtful while its generic placement is clear. The genusTeutonica is known from the Bajocian and Bathonian. It was formerly related to the families Cerithiopsidae or Zygopleuridae. Here the genus is placed with the Polygyrinidae becausePolygyrina andTeutonica are very similar regarding teleoconch shape, course of the growth lines, and the protoconch shape.     

Species identification of the medicinal plant Tulipa edulis (Liliaceae) by DNA barcode marker

Tulipa edulis (Liliaceae) is the botanical origin of the traditional Chinese medicine (TCM) “Guangcigu”. Due to overexploitation that induced a decline in natural sources, many dried bulbs from other species of Tulipa have been used, adulterating the medicine in recent years. This practice may cause a series of inconsistent therapeutic effects and quality control problems in the herbal medicine industry. Hence, three DNA regions (matK, psbA-trnH and rbcL) were evaluated as barcodes for identifying T. edulis and its adulterants. All candidate DNA barcodes were successfully amplified from leaf samples. Based on the sequence divergences, rbcL and psbA-trnH can assign T. edulis and its adulterants to the correct genus, while matK can accurately differentiate T. edulis and its adulterants. Thus, at the DNA level, the matK intergenic region is a more suitable, accurate and applicable identification of T. edulis and its adulterants than rbcL and psbA-trnH.     

Suoidea du Miocène inférieur de Laugnac (Lot-et-Garonne, France)

The fossil vertebrate locality of Laugnac is the type locality of the Neogene mammalian zone MN2b. It has yielded many remains of Suoidea belonging to two different genera.Xenohyus venitor is characterized by its large size and especially its large central upper incisors, I1/ and I2/. It is quite difficult to know its phyletic relationships because the material is not abundant.Hyotherium cf.meisneri is more abundant with a quite good skull, pieces of skull, jaws and isolated teeth. It belongs to a peculiar lineage different from that ofH. major from Saint Gérand-le-Puy, France. It has some similarities withAureliachoerus aurelianensis from later geological levels (MN3-MN5).     

Influence of planktonic and sessile Listeria monocytogenes on Caenorhabditis elegans

Listeria monocytogenes is the etiologic agent of listeriosis, a food-borne disease affecting humans and a variety of animals. In order to combat this pathogen, it is crucial to have an understanding of its natural interplay with the environment. For this reason, the free soil nematode Caenorhabditis elegans was focused upon because of its shared natural habitat with Listeria and its potential as a model organism for Listeria pathogenesis. Previous studies have generated some contradictory results on Listeria’s ability to kill C. elegans, making additional interaction studies such as this more attractive. In our study, we carried out a series of killing assays in a systematic manner using different Listeria strains under different growth conditions. In addition to studying the effects of planktonic cells, we examined the interaction between C. elegans and sessile listerial cells. Our findings suggest that, rather than causing infection and death, L. monocytogenes may extend the life span of C. elegans. This indicates that Listeria is not pathogenic to C. elegans. We also found that C. elegans can feed and ingest sessile cells, as well as carry the pathogen in its gut, implying that C. elegans could be a vehicle for L. monocytogenes spread in the environment.     

Physiological and DNA characterization of Candida maltosa,a hydrocarbon-utilizing yeast

Selected yeasts classified as Candida sake van Uden et Buckley were examined for their physiological, morphological and immunological properties and their DNA relatedness. Candida maltosa Komagata, Nakase et Katsuya is herein recognized as a species separate from C. sake. Candida maltosa was distinguished from C. sake and from C. tropicalis by insignificant DNA reassociation. In addition, C. maltosa was distinguished from C. sake by its higher maximal growth temperature and lower guanine plus cytosine content of its DNA and from C. tropicalis by its failure to utilize soluble starch for growth and its resistance to cycloheximide. The species C. cloacae and C. subtropicalis are placed in synonymy with C. maltosa.     

Characterization of a homolog of DEAD-box RNA helicases in Toxoplasma gondii as a marker of cytoplasmic mRNP stress granules

Toxoplasma gondii is an obligate intracellular protozoan which infects one-third of the human population. Due to its high infection prevalence, Toxoplasma offers an ideal system for the study of host–parasite interaction. Similar to other eukaryotes, Toxoplasma maintains levels and localization of cytoplasmic mRNAs throughout its life cycle as part of a gene regulation network to meet all cellular and biochemical requirements. More recently, it was reported that the presence of cytoplasmic mRNA granules could contribute to the parasite pathogenesis and viability. Here we identified a novel Toxoplasma DEAD-box RNA helicase, referred to as Toxoplasma gondiiHomolog of DOZI (TgHoDI), because of its high homology (81%) to Plasmodium DOZI. TgHoDI is the functional ortholog of yeast DHH1, and its function was authenticated by complementation studies in Δdhh1 yeast strain. We demonstrated that TgHoDI is a marker of cytoplasmic RNA stress granules, which assemble when the parasites experience cellular stresses and translational arrest.     

Fitness of the parasitoid Diadegma insulare is affected by its host's food plants

The diamondback moth, Plutella xylostella (L.) is considered a specialist on Brassicaceae, but it is capable of expanding its food range by incorporation of non-brassicaceous plants into its diet. The use of a new food plant may change food availability and vulnerability of P. xylostella to its natural enemies, especially specialist parasitoids. In this laboratory study, we evaluated the bottom-up effects of two Brassicaceae viz. Brassica napus L. and Descurainia sophia (L.) Webb ex Prantl and two non-Brassicaceae viz. Tropaeolum majus L. and Cleome hassleriana Chodat on several fitness correlates of the specialist parasitoid, Diadegma insulare (Cresson) reared on P. xylostella larvae. Percentage of parasitism of host larvae by D. insulare varied among the plant species and was highest on T. majus and lowest on D. sophia. Values of several fitness correlates for D. insulare differed when the host was feeding on various plant species. Egg to adult development was fastest on B. napus followed by C. hassleriana, D. sophia and T. majus. Female wasps reared on C. hasseleriana lived the longest in absence of food. The response of D. insulare to potential food-plant expansion by its host P. xylostella is discussed.     

On the Identity of the Genus Crassolabium (Dorylaimida: Qudsianematidae)

The identity and taxonomy of the genus Crassolabium are discussed based on examination of material of C. australe, its type species and its comparison with Iberian species of close genera. The existence of refractive masses (thickenings) at the inner core of lateral lips, the most distinctive diagnostic feature of Crassolabium, is considered to be of minor taxonomical significance because of its interspecific and even intraspecific variability. It is concluded that Crassolabium and Thonus are identical, and a reversal of precedence among both genera is suggested. Crassolabium australe is re-described, and some comments are provided on C. robustum, the second species in the genus.     

Systematic studies on the Zygophyllaceae of Saudi Arabia: A new variety and new variety combination in Tetraena

During 2013–2014, fresh material of Tetraena alba was collected from two localities in Saudi Arabia. Detailed morphological examination of these specimens revealed that there is a new variety of this species, for which the name T. alba var. arabica is proposed. Fresh material of Zygophyllum amblyocarpum was also collected from a different locality, and based on its characteristics is transferred to Tetraena with the new combination T. alba var. amblyocarpa. T. alba and its varieties are illustrated and morphological characters supplied to differentiate among them.