Influence of plant and residue age on attraction, acceptance and larval survival of the banana weevil Cosmopolites sordidus (Coleoptera: Curculionidae)

Laboratory trials were conducted in Uganda at the Kawanda Agricultural Research Institute to determine attraction, eclosion success and larval survivorship of the banana weevil Cosmopolites sordidus (Germar) on crop residues of different ages. In the first experiment, studies focused on different types and ages of residues of one susceptible highland banana clone ‘Nabusa’ (genome group AAA-EA). Corms attracted 65% of the test weevils, pseudostems 30%, while 5% were non-respondents. Oviposition levels and the number of eggs per female were higher on young than old corms. Eclosion rates of 30 DAH. To assess immature survival, 30 DAH. Larval duration and mean days taken for adult emergence increased with plant and crop residue age. Females emerging from the different plant and residues treatments were similar in weight. The data suggest that all aged residues are suitable hosts for C. sordidus, suggesting that sanitation practices should be implemented soon after harvest

Effect of age, female mating status and density on the banana weevil response to aggregation pheromone

The banana ( Musa spp.) weevil ( Cosmopolites sordidus (Germar) (Coleoptera: Curculionidae) is a major pest in East Africa causing yield losses of up to 14 metric tonnes per hectare annually. Laboratory and field experiments were conducted to determine whether the response of the banana weevil, Cosmopolites sordidus (Germar) (Coleoptera: Curculionidae) to its aggregation pheromone was influenced by age, female mating status and weevil density. Laboratory bioassays were conducted using a double pitfall olfactometer, while a bucket pitfall trap was used in field experiments. There was no significant (P>0.05) difference in response to pheromone between immature and mature weevils (males and females) in laboratory bioassays. Forty-day-old weevils had a stronger response to the pheromone than 10-day-old ones under field conditions. The response of unmated weevils to the pheromone was stronger than that of mated weevils, both in the laboratory and field. The percentage of unmated and mated weevils recaptured from 0 and 3 m were similar but significantly different from 6 m way from the pheromone baited trap. The response of the weevils to the pheromone was not significantly (P>0.05) influenced by its previous density

Timing and distribution of attack by the banana weevil (Coleoptera: curculionidae) in East African highland banana (Musa spp.)

Timing and distribution of attack on East African highland banana (Musa AAA- EA) by the banana weevil, Cosmopolites sordidus (Germar), (Coleoptera: Curculion- idae) was studied in a field trial at a farm 25 km NE of Kampala, Uganda. Weevils were released at three densities (5, 20 and 40 females per mat) in 324 m' banana plots (cv Atwalira) that had been established 18 months earlier and maintained relatively free of weevils. Two weeks after release, entire mats were removed and examined for weevil eggs and first instar larvae. At a density of 20 weevils per mat, oviposition occurred on 25% of plants less than 6 six months old (suckers) with an average of three eggs (range 0-16) per infested plant. At the same time, 85% of flowered plants were at- tacked with mean oviposition of 15 eggs (range 0-41) per plant. An inverse relation- ship existed between weevil population density and eggs/female/plant. Five females per mat produced an average of 7.2 eggs per flowered plant, whereas 20 females pro- duced 15 eggs per flowered plant and 40 females produced 12.5 eggs. This suggests the existence of density-dependent factors in weevil oviposition. Over 90% of the oviposi- tion occurred in the base of the pseudostem, with the remaining eggs found in the corm and roots near the soil surface. However, in stands displaying high mat, (a con- dition in which part of the corm appears above the soil surface) more eggs were found on the corm than pseudostem

HUBUNGAN PANJANG TUNGKAI DENGAN KEMAMPUAN LOMPATRNJAUH PADA MAHASISWA PROGRAM STUDI PENJASKESREK FKIP UNIVERSITAS SYIAH KUALA TAHUN AKADEMIK 2012/2013

Banda Ace

Olfactory responses of banana weevil predators to volatiles from banana pseudostem tissue and synthetic pheromone

As a response to attack by herbivores, plants can emit a variety of volatile substances that attract natural enemies of these insect pests. Predators of the banana weevil, Cosmopolites sordidus (Germar) (Coleoptera: Curculionidae) such as Dactylosternum abdominale (Coleoptera: Hydrophilidae) and Pheidole megacephala (Hymenoptera: Formicidae), are normally found in association with weevil-infested rotten pseudostems and harvested stumps. We investigated whether these predators are attracted to such environments in response to volatiles produced by the host plant, by the weevil, or by the weevil¿plant complex. We evaluated predator responses towards volatiles from banana pseudostem tissue (synomones) and the synthetic banana weevil aggregation pheromone Cosmolure+ in a two-choice olfactometer. The beetle D. abdominale was attracted to fermenting banana pseudostem tissue and Cosmolure+, whereas the ant P. megacephala was attracted only to fermented pseudostem tissue. Both predators were attracted to banana pseudostem tissue that had been damaged by weevil larvae irrespective of weevil presence. Adding pheromone did not enhance predator response to volatiles from pseudostem tissue fed on by weevils. The numbers of both predators recovered with pseudostem traps in the field from banana mats with a pheromone trap were similar to those in pseudostem traps at different distance ranges from the pheromone. Our study shows that the generalist predators D. abdominale and P. megacephala use volatiles from fermented banana pseudostem tissue as the major chemical cue when searching for pre

Effect of age, female mating status and density on the banana weevil response to aggregation pheromone

The banana ( Musa spp.) weevil ( Cosmopolites sordidus (Germar) (Coleoptera: Curculionidae) is a major pest in East Africa causing yield losses of up to 14 metric tonnes per hectare annually. Laboratory and field experiments were conducted to determine whether the response of the banana weevil, Cosmopolites sordidus (Germar) (Coleoptera: Curculionidae) to its aggregation pheromone was influenced by age, female mating status and weevil density. Laboratory bioassays were conducted using a double pitfall olfactometer, while a bucket pitfall trap was used in field experiments. There was no significant (P>0.05) difference in response to pheromone between immature and mature weevils (males and females) in laboratory bioassays. Forty-day-old weevils had a stronger response to the pheromone than 10-day-old ones under field conditions. The response of unmated weevils to the pheromone was stronger than that of mated weevils, both in the laboratory and field. The percentage of unmated and mated weevils recaptured from 0 and 3 m were similar but significantly different from 6 m way from the pheromone baited trap. The response of the weevils to the pheromone was not significantly (P>0.05) influenced by its previous density.Le Col\ue9opt\ue8re ( Cosmopolites sordidus (Germar) (Coleoptera: Curculionidae) est une importante peste de la banane (Musa spp.) causant de pertes annuelles de rendements allant jusqu' \ue0 14 tonnes par hectare \ue0 l'Est de l'Afrique. Des essais au laboratoire et au champ \ue9taient conduits pour d\ue9terminer si la r\ue9ponse des col\ue9opt\ue8res, Cosmopolites sordidus (Germar) (Coleoptera: Curculionidae) \ue0 leur aggr\ue9gation ph\ue9romonale \ue9tait influenc\ue9e par l'age, le statut sexuel des femelles et la densit\ue9 des col\ue9opt\ue8res. Un olfactom\ue8tre \ue0 double pi\ue8ge \ue9tait utilis\ue9 au laboratoire, alors qu'un pi\ue8ge en forme de sceau \ue9tait utilis\ue9 au champ. Il n'y avait aucune diff\ue9rence significative (P>0.05) en terme de r\ue9ponse aux ph\ue9romones entre les col\ue9opt\ue8res jeunes et \ue2g\ue9s (males et femelles) dans les essais au laboratoire. Les col\ue9opt\ue8res \ue2g\ue9s de quarante jours avaient pr\ue9sent\ue9 une forte r\ue9ponse au ph\ue9romone par rapport \ue0 ceux de dix jours d'\ue2ge en conditions de champ. Au laboratoire et au champ, la r\ue9ponse au ph\ue9romone des col\ue9opt\ue8res non pari\ue9s \ue9tait plus forte que celle des col\ue9opt\ue8res pari\ue9s. Le pourcentage des col\ue9opt\ue8res pari\ue9s et non pari\ue9s mesur\ue9 \ue0 0 et 3 m \ue9tait similaire mais significativement diff\ue9rent \ue0 6 m de distance du pi\ue8ge ph\ue9romonal. La r\ue9ponse de col\ue9opt\ue8res au ph\ue9romone n'\ue9tait significativement (P>0.05) pas influenc\ue9e par leur densit\ue9 initiale

Mobilizing IPM for sustainable banana production in Africa: Proceedings of a workshop on banana IPM held in Nelspruit, South Africa - 23 - 28 November 1998

This 356-page publication is the proceedings of a workshop held in Nelspruit, South Africa in November 1998. Twenty-one valuable communications are included, giving an up-to-date overview on research activities on weevils, nematodes, pathology and farming systems in sub-Saharan Africa. Nine country-case studies are also presented. Working groups' results and recommendations are included. This book will certainly be very useful for all those interested in IPM, especially in Africa

Emergence of quasi-metallic state in disordered 2D electron gas due to strong interactions

The interrelation between disorder and interactions in two dimensional electron liquid is studied beyond weak coupling perturbation theory. Strong repulsion significantly reduces the electronic density of states on the Fermi level. This makes the electron liquid more rigid and strongly suppresses elastic scattering off impurities. As a result the weak localization, although ultimately present at zero temperature and infinite sample size, is unobservable at experimentally accessible temperature at high enough densities. Therefore practically there exists a well defined metallic state. We study diffusion of electrons in this state and find that the diffusion pole is significantly modified due to "mixture" with static photons similar to the Anderson - Higgs mechanism in superconductivity. As a result several effects stemming from the long range nature of diffusion like the Aronov - Altshuler logarithmic corrections to conductivity are less pronounced.Comment: to appear in Phys. Rev.

Performance of the subcutaneous implantable cardioverter-defibrillator in patients with a primary prevention indication with and without a reduced ejection fraction versus patients with a secondary prevention indication

Background: The subcutaneous implantable defibrillator (S-ICD) provides an alternative to the transvenous ICD for the prevention of sudden cardiac death, but has not been well studied in the most commonly treated transvenous ICD patient population, namely, primary prevention (PP) patients with left ventricular dysfunction. Objective: The analyses in the present study were designed to compar