B1 Was the Ancestor B Chromosome Variant in the Western Mediterranean Area in the Grasshopper Eyprepocnemis plorans.

We analyzed the distribution of 2 repetitive DNAs, i.e. ribosomal DNA (rDNA) and a satellite DNA (satDNA), on the B chromosomes found in 17 natural populations of the grasshopper Eyprepocnemis plorans plorans sampled around the western Mediterranean region, including the Iberian Peninsula, Balearic Islands, Sicily, and Tunisia. Based on the amount of these repetitive DNAs, 4 types of B variants were found: B 1 , showing an equal or higher amount of rDNA than satDNA, and 3 other variants, B 2 , B 24 and B 5 , bearing a higher amount of satDNA than rDNA. The variants B 1 and B 2 varied in size among populations: B 1 was about half the size of the X chromosome in Balearic Islands, but two-thirds of the X in Iberian populations at Alicante, Murcia and Albacete provinces. Likewise, B 2 was about one-third the size of the X chromosome in populations from the Granada province but half the size of the X in the populations collected at Málaga province. The widespread geographical distribution of the B 1 variant makes it the best candidate for being the ancestor B chromosome in the whole western Mediterranean region

Global variations in diabetes mellitus based on fasting glucose and haemogloblin A1c

Fasting plasma glucose (FPG) and haemoglobin A1c (HbA1c) are both used to diagnose diabetes, but may identify different people as having diabetes. We used data from 117 population-based studies and quantified, in different world regions, the prevalence of diagnosed diabetes, and whether those who were previously undiagnosed and detected as having diabetes in survey screening had elevated FPG, HbA1c, or both. We developed prediction equations for estimating the probability that a person without previously diagnosed diabetes, and at a specific level of FPG, had elevated HbA1c, and vice versa. The age-standardised proportion of diabetes that was previously undiagnosed, and detected in survey screening, ranged from 30% in the high-income western region to 66% in south Asia. Among those with screen-detected diabetes with either test, the agestandardised proportion who had elevated levels of both FPG and HbA1c was 29-39% across regions; the remainder had discordant elevation of FPG or HbA1c. In most low- and middle-income regions, isolated elevated HbA1c more common than isolated elevated FPG. In these regions, the use of FPG alone may delay diabetes diagnosis and underestimate diabetes prevalence. Our prediction equations help allocate finite resources for measuring HbA1c to reduce the global gap in diabetes diagnosis and surveillance.peer-reviewe

Effectiveness of Lysiphlebus testaceïpes Cresson as biocontrol agent of Aphis gossypii Glover infesting pepper plants

In Tunisia, greenhouse crops are damaged by Aphis gossypii Glover and Myzus persicae Sulzer (Ben Halima Kamel 1991; Ben Halima Kamel and Ben Hamouda 1993, 1998). These aphids are considered to be the most dangerous pests of pepper because of their biology and biotic potential (Ben Halima Kamel 1991; Blackman and Eastop 2000). There are several ways of controlling these pests with chemical control being the most widely used. This method has more disadvantages than benefits (Gibson et al. 1982). The use of natural enemies to control aphids is an effective way of improving the yield and quality of protected crops. There are many studies on the following naturally occurring enemies of A. gossypii: Aphidius matricariae Haliday, Lysiphlebus fabarum Marshall, Aphidoletes aphidimyza (Rondani), Episyrphus balteatus (De Geer) (Ben Halima Kamel and Ben Hamouda 1998) and Lysiphlebus testaceipes (Cresson) (Ben Halima Kamel, unpublished data, 1999). It is now important to evaluate the effectiveness of L. testaceipes as a biocontrol agent of A. gossypii. This parasitoďd was introduced into the Mediterranean area (Carver and Franzmann 2001) and is thought to be an important parasite of A. gossypii (Lopes et al. 2007). The aim of this mainly laboratory study was to determine the factors affecting the establishment and success of a biological control agent, in particular the number of L. testaceďpes relative to the initial density of A. gossypii, needed to control the aphid. In addition, the effect of the L. testaceďpes on structure of A. gossypii populations was evaluated. Furthermore, the effectiveness of L. testaceipes in controlling A. gossypii infesting a protected crop of pepper plants and the subsequent effect on the growth of the pepper plants was also evaluated

Identification of an insecticidal polyacetilene derivative from Chrysanthemum macrotum leaves

Compounds responsible for insecticidal properties of Chrysanthemum macrotum (D.R.) Ball. leaves against Spodoptera littoralis Boiduval caterpillars have been investigated. The screening of the insecticidal activity was performed by incorporating methanol, buthanol or ethyl acetate extracts, or some chromatographic fractions to the caterpillars’ artificial diet. It was noted that extracts and fractions ameliorated or disturbed nutritional indexes, being not always toxic for caterpillars. Among the tested fractions, one pure compound with a high insecticidal activity (percentage of mortality 66.7%) was purified. The nuclear magnetic resonance study allowed its identification as a polyacetylene derivative, in particular a spiroketal enol ether one

Feeding perturbation and toxic activity of five Chrysanthemum species crude extracts against Spodoptera littoralis (Boisduval) (Lepidoptera; Noctuidae)

The effect of the whole methanol extracts of five Chrysanthemum species on feeding and performance of Spodoptera littoralis (Boisduval) larvae has been investigated in vitro. The extracts exhibited antifeeding and phagostimulating activities against cotton leafworm larvae when applied either on leaf discs or incorporated into an artificial diet. Under chosen conditions, the antifeedant index calculated over 24 h for sixth instar larvae significantly varied from 78.55 for Chrysanthemum segetum L. to -44.18 for Chrysanthemum fuscatum Desf. at the dose of 1000 ppm. Toxicity of the extracts was manifested by a high mortality, reduced growth rates, and low weight gain by larvae fed on diets containing 1000-10,000 ppm of the extract. Anyone of the larvae treated with Chrysanthemum macrotum (D.R.) Ball. leaves crude extract survived to pupation at the two higher concentrations. The time to pupation increased for Chrysanthemum grandiflorum flowers crude extract from 11.40±0.93 to 28.93±10.92 days as the extract concentration in the diet increased from 0 to 10,000 ppm. The ingestion of crude extract by the third instar larvae reduced significantly the consumption, growth and utilisation of the ingested and digested food, and reduced digestibility. The crude extract of the leaves of C. macrotum, dissolved in acetone and topically applied on sixth instar larvae, showed a quite high mortality (95%). These results suggest the presence in the extracts of anti-feeding and/or toxic substances, active by consumption and topical application. The identification of these compounds and their action mode will be object of further studie

Insecticidal and anti-appetent activities of four Chrysanthemum species against Tribolium confusum Du Val (Coleoptera: Tenebrionidae)

Insect pests are one of the major factors limiting the production and the storage of agricultural products. The use of synthetic pesticides limits the damage of these pests. However, the effectiveness of these products is continually eroded by the development of resistance in these pests and serious health and ecological disadvantages were detected. It is clear that there is an urgent need for alternative control measures, which must be active against the pests, safe to humans and environmentally friendly. Evaluation of local plants as sources of protectants is one of the promising ways to fulfil this need. In this study the essential oil of four Chrysanthemum species (C. macrotum, C. trifurcatum, C. segetum and C. fuscatum) were evaluated for their insecticidal activity against Tribolium confusum using tow methods: fumigation and consumption. The essential was diluted in acetone to obtain the concentration of 1%. For the fumigant activity, 100 μl of the solution was applied on filter paper (1x2.5 cm), after evaporating the solvent, each filter paper was placed on the underside of the screw cap of a glass vial and was screwed tightly onto the vial containing ten adults of Tribolium confusum. Concerning the evaluation of the anti-appetent activity, 5 μl of each Chrysanthemum species essential oil were applied on flour disc (95% wheat semolina and 5% beer yeast). The control received only acetone and five replicates were set up for each treatment and control. The results showed that essential oil obtained from flowers of C. macrotum and those from leaves of C. trifurcatum have the highest fumigant activity and cause respectively the mortality of 48 and 40% against adults of T. confusum. The study of anti-appetent effect on larvae of T. confusum showed that C. segetum flowers essential oil has the significant feeding deterrent index (92.45±4.61) followed by the leaves essential oil obtained from C. fuscatum (71.20±19.22), without having a significant mortality on this larvae. The study of essential oil composition of the four Chrysanthemum species highlighted their richness on mono and sesqueterpenes that are known for their insecticidal activity. Though these findings are preliminary, they could represent the basis for further investigations on the questions raised in this work. In particular, additional research is needed to investigate the susceptibility of other stages of the insect life, such as pupae and eggs and to improve our understanding of how mono- and sesquiterpenoids act on insects. Practically, in view of a possible use of the most active mono- and sesquiterpenoids, it should be pointed out that longer exposure periods could be needed to bridge the tolerant phases of insects, some of which could be present at the time of application

Chemical composition and bioactivities of three Chrysanthemum essential oils against Tribolium confusum (du Val) (Coleoptera: Tenebrionidae)

Essential oils from three species of Chrysanthemum growing in Tunisia (C. coronarium, C. fuscatum, and C. grandiflorum) were first analyzed by gas chromatography (GC) and GC/mass spectrometry (MS) and then evaluated for toxicity and antifeeding action against Tribolium confusum. The essential oils obtained from leaves and flowers shared a similar qualitative composition, but the relative proportions of the constituents were quite different. The essential oil of C. grandiflorum was rich in sesquiterpenoids, while those of C. fuscatum and C. coronarium were rich in monoterpenoids. The main common constituents of all the essential oils were α-pinene, myrcene, α-humulene, β-caryophylene, spathulenol, and caryophyllene oxide. The most effective essential oil was obtained from the leaves of C. grandiflorum, that inhibited the relative growth rate (−0.03 mg/mg/d), efficiency of conversion of ingested food (−50.69%), relative consumption rate, caused an antifeeding effect (66.43%) and a high mortality (80%) of T. confusum larvae. Topical application C. grandiflorum essential oil caused a significant insect mortality that attends 27% after 7 days of treatment. While essential oil from C. coronarium flowers has contact and fumigant toxicity with a mortality of 9 and 13%, respectively. Results analysis highlights a relationship between essential oils composition and insecticidal activity against T. confusum. The study showed that each essential oil has specific chemical composition and act differently according to the nature of attributed test. The use of essential oils from different Chrysanthemum species with different methods helps poor farmers who store small amounts of grains to preserve it against pest infestatio