bluuebunny/crossref_metadata_2025 huggingface dataset:
Mosquito control in Dar es Salaam.
Authors: CHAVASSE D. C. , LINES J. D. , ICHIMORI K. , MAJALA A. R. , MINJAS J. N. , MARIJANI J.
Published: March 2008

Abstract. In two contrasting areas of Dar es Salaam (Ilala and Mikocheni) all enclosed breeding sites of Culex quinquefasciatus, such as latrines and septic tanks, were treated with a floating layer of expanded polystyrene beads. 7 months later checks in both study areas revealed only one site (from which the polystyrene had been removed during emptying) containing immature stages of Cx quinquefasciatus.

Open breeding sites such as areas of flooded land and blocked drains were treated with pyriproxyfen (an insect growth regulator) at a concentration of 0.1 ppm. Emergence of Cx quinquefasciatus adults from these sites was inhibited for 4 weeks during the rainy season and for up to 11 weeks during the dry season.

The problem of mosquito breeding sites caused by bathroom sullage water was addressed through a combination of health education and indirect pressure from the Urban Malaria Control Project (UMCP) via local community leaders. Households responsible for these sites were encouraged to eliminate them by diverting the water into an enclosed drainage structure, usually a pit latrine. After two weekly visits 64.7% of households had complied and 93.4% had complied after five visits. 5 months later, only 15.7% had reverted to allowing sullage water to collect into puddles.

Densities of Cx quinquefasciatus adults dropped by 76.7% in Mikocheni and by 46.2% in Ilala following intervention, but increased by 84.9% and 25.6% in two untreated comparison areas. The reasons for differential success of the combined interventions in the two treated areas are discussed.
Pyrethroid‐impregnated hessian curtains for protection against mosquitoes indoors in South India
Authors: POOPATHI S. , RAO D. RAGHUNATHA
Published: March 2008

Abstract. Hessian curtains impregnated with deltamethrin 50 mg/m2 were hung in the eaves and doorways of eight one‐roomed huts in Madurai, Tamil Nadu State, South India. Statistically significant reductions of indoor‐resting and man‐biting densities of the mosquitoes Anopheles subpictus and Culex quinquefasciatus were observed for 14 weeks, in two field trials. Bioassays on curtains in the field showed over 50% mortality of Cx quinquefasciatus and An. stephensi for up to 8 weeks. The curtains were highly acceptable to the community, and cost approximately Rs.33.15 (US1.05) for material and Rs.10 (0.32) for deltamethrin per hut, totalling Rs 53.15 (1.70) for two impregnations giving 6 months protection. Comparative costs of house‐spraying with residual insecticides are estimated as Rs.1.92 (0.06) for two rounds of DDT at lg/m2, or Rs.40 (1.27) for three rounds of malathion at 2g/m2. Therefore the relative annual cost of protection using deltamethrin‐impregnated hessian curtains is 28× or 1.3× more than for house‐spraying with DDT or malathion, respectively (excluding operational expenditure).
Identification of screwworm species by polymerase chain reaction‐restriction fragment length polymorphism
Authors: TAYLOR DAVID B. , SZALANSKI ALLEN L. , PETERSON RICHARD D.
Published: March 2008

Abstract. Restriction fragment length polymorphisms in polymerase chain reaction amplified fragments (PCR‐RFLP) of mitochondrial DNA were used to differentiate species of New World screwworms (Diptera: Calliphoridae). Twenty‐seven restriction enzymes were screened on five regions of mtDNA. Eleven restriction fragment length patterns differentiated New World screwworm, Cochliomyia hominivorax (Coquerel), from secondary screwworm, Cochliomyia macellaria (R). Five restriction fragment length patterns were polymorphic in C. hominivorax while all fragment patterns were fixed in C. macellaria. Diagnostic restriction fragment length patterns were used for species diagnosis, whereas intraspecific variable patterns were used to characterize field samples and laboratory strains. The PCR‐RFLP technique is flexible with regard to developmental stage of the sample and method of preservation. We were able to characterize specimens of all life stages from egg to adult including larvae preserved in alcohol and pinned adults. PCR‐RFLP is rapid and inexpensive, enabling specimens to be characterized within 24 h for less than 2.50.
Long‐term use of permethrin‐impregnated nets does not increase Anopheles gambiae permethrin tolerance
Authors: VULULE J. M. , BEACH R. F. , ATIELI F. K. , MOUNT D. L. , ROBERTS J. M. , MWANGI R. W.
Published: March 2008

Abstract. Previous use of permethrin‐impregnated bednets (mosquito nets) and curtains in four Kenyan villages for one year, 1990‐91, raised the permethrin LT50 of Anopheles gambiae to 2.4‐fold above its baseline value, designated permethrin tolerance (PT), as measured by exposure to 0.25% permethrin‐impregnated papers in W.H.O. test‐kits. During 1992‐93, with ongoing use of permethrin‐impregnated nets and curtains, PT regressed slightly compared with the contemporary susceptibility level of An. gambiae from non‐intervention villages, to 1.8‐fold in 1992 and only 1.6‐fold in 1993. Thus the selection pressure of impregnated nets for PT in Angambiae appears to be minimal in our study villages, although the impact of permethrin was demonstrated by a significantly lower parous‐rate of Angambiae females in the intervention (63–66%) than in non‐intervention (79%) villages, and by reduced malaria transmission (reported elsewhere).

In a selected stock of An. gambiae from the study area, PT did not affect the susceptibility to deltamethrin, fenitrothion, propoxur or DDT. Bioassays described herein provide easy procedures for field‐monitoring of mosquito susceptibility/tolerance/resistance to insecticides used for net impregnation in operational programmes.
Temperature‐dependent development and survival of the lesser mealworm, Alphitobius diaperinus
Authors: RUEDA L.M. , AXTELL R. C.
Published: March 2008

Abstract. Development, growth and survival of the lesser mealworm, Alphitobius diaperinus (Panzer), were determined at six constant temperatures. No egg hatch or larval development occurred at 17oC. At temperatures of 20, 25, 30, 35 and 38oC the median development times (days), respectively, were for eggs (13.4, 6.0, 4.4, 2.6 and 2.6), larvae (133.0, 46.0, 26.2, 22.4 and 23.9), pupae (17.0, 8.0, 5.5, 4.0 and 4.1), and from oviposition to adult emergence (164.4, 60.2, 37.9, 29.0 and 30.8). The Sharpe & DeMichele (1977) model was used to describe the temperature‐dependent development. The mean egg survival (hatching) ranged from 61% to 86%, with lowest hatch at 20oC. Survival of the larvae and pupae ranged from 32% to 73% and from 85% to 95%, respectively, with lowest survival at 20oC. Pupae had significantly lower weights at 35oC and adults at 38oC than at the other temperatures. Female pupae (20 mg) and female adults (16 mg) were significantly heavier than male pupae (17 mg) and male adults (13 mg). Adults (0.5–9 months old) laid 4–7 eggs per female per day at 25oC.
A self‐medicating applicator for control of ticks on deer
Authors: SONENSHINE DANIEL E. , ALLAN SANDRA A. , NORVAL R. ANDREW I. , BURRIDGE MICHAEL J.
Published: March 2008

Abstract. A self‐medicating applicator for killing ticks on deer and domestic ungulates by passive transfer of acaricides during feeding is described. The applicator consists of a barrel divided into a food bin (above) and a sealed self‐contained acaricide reservoir (below) with a vertical, centrally‐located ceramic column that extends from the reservoir into the food bin. Acaricide is drawn up the column from the sealed reservoir by absorption. Animals attracted to the food in the device acquire the acaricide during feeding when they contact the uppermost portion of the column.

White‐tailed deer (Odocoileus virginianus) readily utilize the applicator in penned and natural conditions. In a field study, examination of hunter‐killed deer demonstrated that animals from a treated site were infested with many fewer Ixodes scapularis (3.4 ± 1.1) than those from a control site (10.8 ± 3.0). Chromatographic analysis of hair samples revealed traces of permethrin on three of the four animals examined, suggesting use of applicators by these deer. In a study using penned goats {Capra hircus) infested with Amblyomma americanum ticks, treatment efficacy reached 86.4% within 4 days of exposure to the applicators. Visual observations confirmed that all animals used the applicators. Gas chromatographic analysis of goat hair samples indicated that permethrin was detectable on all of the treated animals exposed to the device.
Genetic variation in populations of Culicoides variipennis complex in the six New England states, U.S.A.
Authors: HOLBROOK FREDERICK R. , TABACHNICK WALTER J. , BRADY ROBERT
Published: March 2008

Abstract. We investigated the identity and distribution of members of the Culicoides variipennis complex in the six New England states of the U.S.A., a region where bluetongue transmission has not been detected. Analyses of seven polymorphic isozyme‐encoding loci showed that only C.v.variipennis, not considered to be a vector of the bluetongue viruses, was present. The populations of C.v.variipennis were significantly more hetero‐zygous than C.v.sonorensis and Cv.occidentalis populations from similar studies in the state of California. Estimates of genetic diversity among populations of C.v.variipennis in New England were similar to C.v.sonorensis in the state of Colorado, but were significantly more genetically divergent than California populations of Cv.occidentalis. The impact of these findings on the status of New England as a possible bluetongue‐free region for the purpose of international trade in ruminant livestock and their germplasm is discussed.
Effects of variations in a formulated protein meal on the fecundity and fertility of female mosquitoes
Authors: COSGROVE JONATHAN B. , WOOD ROGER J.
Published: March 2008

Abstract. A formulated protein meal developed by Kogan (1990) for adult female Aedes aegypti mosquitoes was evaluated and modified to increase egg and pupal yield. A vigorous laboratory colony was maintained with the females fed exclusively on this dietary formula for about twenty‐five generations over more than 2 years. Extra modifications were made to produce a diet suitable for Anopheles arabiensis and Anopheles stephensi females to produce eggs. Both formulations contain bovine albumin, haemoglobin and globulin in a ringer based solution, plus ATP as a phagostimulant for Ae.aegypti. Compared to Kogan's original, our Aedes formula doubled the production of pupae per female after a single meal, although the yield was still significantly lower than from mosquitoes fed on animal hosts or defibrinated pig blood. In varying the proportions of different constituents during attempts to optimize the formula, no relationship was found between total protein content (within the range 80–220 mg/ml) and fecundity, percentage hatch or pupal yield of Ae.aegypti. Equivocal results were found when an isoleucine supplement was added to the formula.
Histological and immunological reaction of cattle skin to first‐instar larvae of Dermatobia hominis
Authors: OLIVEIRA‐SEQUEIRA T. C. G. , SEQUEIRA J. L. , SCHMITT F. L. , DE LELLO E.
Published: March 2008

Abstract. Six cattle that had earlier exposure to Dermatobia hominiswere infested experimentally with first‐instar larvae of the parasite. Skin biopsies taken at intervals were studied in wax and in plastic sections. The avidin‐biotin‐peroxidase method was used to detect the presence and localization of host immunoglobulins (Igs) G and M and antigens of first and second instar larvae of Dermatobia hominis.The larvae penetrated actively through the skin and migrated towards the subcutaneous tissues. The great numbers of eosinophils suggest that they are the most important cell in mediating damage to D.hominislarvae. The immunoglobulins bound only to dead or moulting larvae in which access to binding sites may have been altered. This could represent a morphological manifestation of a mechanism that protects larvae from the host immune response. Large amounts of soluble antigens detected along the fistulous tract may be important in the maintenance of this tract by disturbing the normal cicatrization process.
Trapping oestrid parasites of reindeer: the response of Cephenemyia trompeand Hypoderma tarandi tobaited traps
Authors: ANDERSON JOHN R. , NILSSEN ARNE C.
Published: March 2008

Abstract. At 340–360 km North of the Arctic Circle in Norway, Hypoderma tarandi(L.) and Cephenemyia trompe(Modeer) females were caught in baited traps from 10 July to 21 August. During three summers, adverse climatic conditions inhibited flight activity of these oestrids on 56–68% of the days. Flies were not caught prior to or after these dates, nor at winds above 8 m/s, temperatures below 10d̀C, light intensities below 20,000 lux, or during periods of rain or snow. C02‐baited insect flight traps caught significantly more H. tarandifemales than non‐baited traps. However, neither a white reindeer hide or reindeer interdigital pheromone glands enhanced the attraction of C02to H. tarandior C. trompe. Hypoderma tarandifemales also were attracted to mobile people, but not to stationary individuals. There were no significant differences in the numbers of C.trompeor H.tarandicaught in C02‐baited traps in a birch/willow woods, on the treeless vidda (=tundra‐like biome), or at woodsrvidda ecotone sites. Flies were caught in traps on days when the nearest reindeer herds were 25–100 km away. Significantly more H.tarandiand C.trompewere caught from 09.30 to 14.30 hours than from 14.30 to 19.30 hours; no flies were caught from 20.00 to 07.00 hours (Norwegian Standard Time = NST). Because COz‐baited traps caught from hundreds to thousands of mosquitoes, blackflies and Culicoidesmidges, when climatic conditions inhibited oestrid activity, reindeer aggregations and movements attributed to insect attacks during warm sunny days may be largely in response to attacks by H.tarandiand C.trompe.
The occurrence of ixodid ticks on wild mink Mustela visonin England and Wales
Authors: PAGE R. J. C. , LANGTON S. D.
Published: March 2008

Abstract. Four species of ticks found to infest 1391 American mink (Mustela vison)in Britain in five years were, in declining order of frequency, Ixodes hexagonus, Ixodes canisuga, Ixodes ricinusand Ixodes acuminatus. Ixodes hexagonusand I.canisugaoccurred on 40% and 2.5% of mink respectively. Infestation rates (the proportion of infested mink) of adult females, nymphs and larvae were similar and tended to be lower in summer. The distribution of infestation size (the number of ticks per host) for adult females describes a negative binomial. The mean infestation size of nymphs varied with the sex of the host and was 5.2 for males and 4.2 for females. Mink are competent hosts for /. hexagonus.
The use of carrion as breeding sites by the blowfly Lucilia sericata and other Calliphoridae
Authors: SMITH K. E. , WALL R.
Published: March 2008

Abstract. To examine the species composition of flies breeding in carrion in the field, the carcasses of mice and quail were exposed on sheep farms in the South West of England. Calliphora vicina was the dominant species of Diptera; 19,294 individuals emerged from 175 of the 241 infested carcasses recovered. Lucilia sericata emerged from only 39 of the infested carcasses, at a median of 10 adults per infested carcass. Other species of Lucilia present were L.ampullacea, L.caesar and L.illustris. The highest number of L.sericata emerged from carcasses placed in open pasture, the highest number of C.vicina emerged from carcasses in hedgerow, whereas the highest numbers of L.caesar, L.ampullacea and L.illustris emerged from carcasses in woodland. The duration of exposure of carcasses in the field was negatively related to the size of the adult L.sericata which emerged and, in woodland and hedgerow habitats, to the number of L.sericata which emerged. These data indicate that the larvae of L.sericata in carcasses experience significant levels of competition and that the intensity of this competition may be sufficient to reduce the numbers of L.sericata able to emerge successfully. The size distributions of female L. sericata which emerged from carcasses or which were caught as adults in the field showed only a small degree of overlap, suggesting that only a relatively small proportion of the wild L.sericata population emerge from carcass breeding sites. The results are discussed in relation to the development of new approaches to the control of blowfly strike of sheep.
Spatial and seasonal distribution of Culicoides imicola in Iberia in relation to the transmission of African horse sickness virus
Authors: RAWLINGS PETER , PRO MARIA‐JOSÉ , PENA ISABEL , ORTEGA MARIA‐DOLORES , CAPELA RUBEN
Published: March 2008

Abstract. Collections of biting midges were made over 24 months from sixty sites spread across Iberia. Information on the distribution of the vector of African horse sickness virus, Culicoides imicola, from these 3119 samples showed that this species was annually present across south‐western Spain as far as 3o53'W and throughout most of Portugal, up to 41o5'N. C.imicola was found in all areas where African horse sickness epizootics had occurred in 1987‐90 and also in areas outside the epizootic zones.

Seasonal patterns of capture success of C.imicola, from seventeen frequently sampled sites where the vector was present, usually showed a late summer‐early autumn peak. At the sites furthest south there was a discrete peak, mostly in September or October, before and after which the numbers captured increased or decreased steadily. At higher latitudes peak abundances occurred as early as May or as late as November, population build up was less uniform and numbers often declined rapidly after the peak was reached. Both the distribution and seasonal abundance patterns closely matched transmission patterns of African horse sickness virus, which rose during late summer and caused most cases during the autumn months.
The responses of Lucilia cuprina to odours from sheep, offal and bacterial cultures
Authors: MORRIS M. C. , JOYCE M. A. , HEATH A. C. G. , RABEL B. , DELISLE G. W.
Published: March 2008

Abstract. The responses of gravid female Lucilia cuprina to odours from sheep urine, faeces and gut mucus, and to odours from liver/sodium sulphide mixtures was tested using a bioassay which measured the movement and probing response of walking flies. The same bioassay was used to test the response to odours from cultures of bacteria isolated from liver/sodium sulphide and liver/water mixtures. A significant movement towards odours from faeces, gut mucus and urine was observed. Odours from cultures of the bacteria Proteus mirabilis, Dermatophilus congolensis and Serratia marcescens also elicited significant movement. A probing response was elicited by odours from gut mucus, fresh urine, liver/sodium sulphide mixtures and cultures of P.mirabilis, D.congolensis and gram‐positive species. Odours from cultures of Pseudomonas aeruginosa, Entero‐bacter aerogenes and Citrobacterfreundii did not elicit significant movement or probing. The movement and probing responses are discussed with reference to the possible uses of the substances tested as a bait for attracting L.cuprina.
The effects of the brown ear‐tick, Rhipicephalus appendiculatus, on milk production of Sanga cattle
Authors: NORVAL R. A. I. , SUTHERST R. W. , KURKI J. , KERR J. D. , GIBSON J. D.
Published: March 2008

Abstract. Lactating Sanga cows of the Mashona breed from Zimbabwe, receiving either a low or a high level of nutritional supplement, were exposed to two levels of infestation of adults of the brown ear‐tick, Rhipicephalus appendiculatus in the highveld of Zimbabwe. The effect of the ticks on the milk yield was measured over an 11‐week period during the rainy season from January to April 1986. A technique in which calves were weighed before and after suckling was used to estimate milk yield. There were significant treatment effects of ticks (P < 0.05) on milk production but no significant differences in liveweight gain between calves from tick‐free and tick‐infested dams. The loss in milk production was poorly related to the number of female ticks that engorged, being 9 g (SEM 4) per tick. A Friesian x Hereford (Bos taurus) reference group of cattle carried 50% more ticks than the Mashona cows, illustrating a difference in resistance between the breeds. Thirteen screw‐worm (Chrysomya bezziana) strikes were recorded amongst the thirty‐two Mashona cows compared with twenty‐one amongst the ten Friesian × Hereford animals between January and the end of March.
Scanning electron microscopy studies on the first‐instar larva of Dermatobia hominis
Authors: FILIPPIS THELMA DE , LEITE A. C. R.
Published: March 2008

Abstract. First‐instar larvae of Dermatobia hominis collected 1, 4 and 7 days after having penetrated experimentally infected rats, were studied by scanning electron microscope (SEM) observation. On the pseudocephalon there are basiconic and trichoid sensilla (antennal sensory complex), and basiconic, coeloconic and campaniform sensilla (maxillary sensory complex). The thoracic segments bear several rows of small, backwardly pointed, spines, and trichoid, campaniform, coeloconic and pit sensilla. The anterior spiracle is a minute opening. Both small and large spines directed posteriorly are on the first to fourth abdominal segments, which also bear coeloconic and companiform sensilla. These sensilla are present on the unarmed (fifth and sixth) and armed (seventh) abdominal segments. The seventh and the last (eight) abdominal segments have forwardly directed spines. Each spiracular plate has two spiracular openings and four spatulate‐like structures called sun rays. The anus and the coeloconic sensilla are proeminent on the last segment. The results are compared with other parasitic dipteran larvae, and emphasize that the multiple types of sensilla on D. hominis larva may have importance in establishing the parasitic phase of the life cycle of this insect.
Responses of mosquitoes of the Anopheles farauti complex to 1‐octen‐3‐ol and light in combination with carbon dioxide in northern Queensland, Australia
Authors: HURK ANDREW F. VAN DEN , BEEBE NIGEL W. , RITCHIE SCOTT A.
Published: March 2008

Abstract. In northern Queensland, Australia, three experiments were conducted to determine the response of mosquitoes of the Anopheles farauti complex to CDC traps baited with four attractant combinations: octenol + C02 and light; octenol and light; CO, and light; or C02 and octenol without light. A CDC‐modified updraft light‐trap was also trialled, but did not significantly enhance collections of An.farauti sensu lato. The combination of light, octenol and C02 caught significantly more An.farauti s.l. (both An.farauti No. 1 and No. 2 sibling species) when compared to C02 and light alone. Only small numbers of the An.farauti complex were captured when CDC traps were baited with octenol alone, i.e. no light or C02.
Development and survival of immature Culex annulirostris mosquitoes in southeast Queensland
Authors: MOTTRAM P. , KETTLE D. S.
Published: March 2008

Abstract. The rates of development and survival of the immature stages of Culex annulirostris were studied in three different breeding sites in the Brisbane area of southeast Queensland: a temporary rain‐filled pool (TP), a semi‐permanent pool (SPP), and an area of flooded grassland (FG) arising from the overflow of a permanent pond. Parallel observations were made on larvae and pupae either exposed to predation or in predator‐free cages for 12 and 15 consecutive days respectively. Development was fastest and survival highest in the warmer TP. Average daily mortality of larvae (L) and pupae (P) was TP: L 8.3%, P 9.5%; SPP: L 25.2%, P 34.6%; FG: L 18.8%, P 35.4%. From life‐tables and survivorship curves, survival from first instar to adult was TP 34.8%, SPP 2.0% and FG 4.2%. Mortality from predation was TP 43.2%, SPP 68.7% and FG 69.1 %. Predator density was TP 0.32, SPP 1.48 and FG 1.76 per 300ml sample.
A circadian rhythm of locomotor activity in newly emerged Ceratophyllus sciurorum
Authors: CLARK FRANK , DEADMAN DEREK , GREENWOOD MALCOLM , EN KIM SøHOLT LARS
Published: March 2008

Abstract Circadian rhythm in newly emerged individuals of the Red Squirrel (Scuirus vulgaris) flea C.s. sciurorum was studied in a constant environment, using an insect activity monitor. Trials were run over 7 days using two start times (08.00 and 17.00 hours). The results show that, regardless of start time, the fleas display a 24 h activity rhythm. The presence of a rhythm under constant conditions gives a strong indication that C. s.sciurorum has a self‐sustaining clock which is started by disturbance and is most likely to be linked to host activity patterns.
Mouthparts, antennae and genitalia of intersex Culicoides stellifer parasitized by mermithid nematodes
Authors: McKEEVER STURGIS , BRICKLE DEBORAH S. , HAGAN DANIEL V.
Published: March 2008

Abstract A 12‐month study of Culicoides in Bulloch County, Georgia, U.S.A., revealed that twelve of23,859 specimens (0.05%) of C.stellifer were intersexes as a result of being parasitized by mermithid nematodes. Of these, eleven had male genitalia and female type antennae and one had female genitalia with male type antennae.
Mapping tsetse habitat suitability in the common fly belt of Southern Africa using multivariate analysis of climate and remotely sensed vegetation data
Authors: ROBINSON TIMOTHY , ROGERS DAVID , WILLIAMS BRIAN
Published: March 2008

Abstract The distribution of Glossina morsitans centralis, Glossina morsitans morsitans and Glossina pallidipes are described in part of southern Africa, using a range of multivariate techniques applied to climate and remotely sensed vegetation data. Linear discriminant analysis is limited in its predictive power by the assumption of common co‐variances in the classes within multivariate environment space. Maximum likelihood classification is one of a variety of alternative methods that do not have this constraint, and produce a better prediction, particularly when a priori probabilities of presence and absence are taken into account. The best predictions are obtained when the habitat is subdivided, prior to classification, on the basis of a bimodality detected on the third component axis of a principal component analysis. The results of the predictions were good, particularly for G.m.centralis and G.m.morsitans, which gave overall correct predictions of 92.8% and 85.1 %, with a Kappa index of agreement between the predion and the training data of 0.7305 and 0.641 respectively. For G.pallidipes, 91.7% of predictions were correct but the value of Kappa was only 0.549. Very clear differences are demonstrated between the habitats of the two subspecies Gmxentralis and G.m.morsitans.
Effects of Plasmodium yoelii nigeriensis infection on Anopheles stephensl egg development and resorption
Authors: CARWARDINE S. L. , HURD H.
Published: March 2008

Abstract It has been shown previously that infection with Plasmodium yoelii nigeriensis reduces the number of eggs produced by female Anopheles stephensi. Here we examine the mechanism underlying fecundity reduction. Ovaries from infected and uninfected (control) female mosquitoes were examined12, 24 or 36 h after blood‐feeding during the first gonotrophic cycle (replicated) or the second gonotrophic cycle (unreplicated). Follicular development was assessed according to Christophers' stages and the proportions of developing and resorbing follicles per ovary were determined. Resorption of some follicles commenced within 12h of blood‐feeding, affecting significantly more follicles in the infected females: 1.1% v. 3.2%. The difference was greatest 36h after blood‐feeding: 25% reduction (10 v. 35%) in the first cycle; 16% reduction (9 v. 25%) in the second gonotrophic cycle. The mean speed of oogenesis was also found to be significantly retarded in infected mosquitoes. During the second gonotrophic cycle, for example, only 92–94% of follicles reached stage III by 24 h and stage IV by 36 h in infected females, whereas all the developing follicles of uninfected females reached these stages more or less synchronously in the time specified.
Control of Trypanosoma brucei brucei infections in tsetse, Glossina morsitans
Authors: WELBURN SUSAN C. , MAUDLIN IAN
Published: March 2008

Abstract Numbers of immature Trypanosoma brucei brucei within a tsetse midgut remain remarkably constant after establishment throughout the course of an infection, irrespective of whether the infection eventually matures. These results suggest a system of self regulation of the parasite population in the insect gut based on a form of programmed cell death which would carry advantages for both the parasite and the vector.
The gecko: an environmentally friendly biological agent for mosquito control
Authors: CANYON D. V. , HII J. L. K.
Published: March 2008

Abstract Laboratory experiments with Aedes aegypti mosquitoes investigated the effects of light, mosquito density and physiological state on predation rates by the Australian gecko Gehydra dubia and the exotic Asian house gecko Hemidactylusfrenatus.

For both gecko species a positive correlation was demonstrated between prey density and the predation rate. Using Ae.aegypti males and unfed females as prey in a terrarium (0.054m3), consumption rates reached 76–108/day for G.dubia and 63–109/day for H.frenatus, with significantly more female mosquitoes than males being eaten in most experiments. Comparing dark with semi‐illuminated conditions no consistent contrast of predation rate was demonstrated.

Gehyra dubia predation rates on various Australian mosquito species were compared in an experimental room (32 m3) for 24 h exposure with photoperiod L:D 12:12h. Five photophilic species (Aedes vigilax, Anopheles annulipes, Coquillettidia xanthogaster, Culex annulirostris, Cx sitiens) suffered 78–100% predation, compared with only 33–53 % predation of four non‐photophilic species: Aedes aegypti, Ae. notoscriptus, Ae. vittiger and Cx quinquefasciatus. This demonstrates the potential benefit of domestication for geckoes that learn to hunt at light.

When offered a mixture of unfed, freshly blood‐fed and gravid females of Ae.aegypti in an illuminated terrarium, both gecko species consumed significantly more unfed than fed or gravid female mosquitoes, presumably because the latter rested wheras the former foraged more actively. H.frenatus consumed significantly more mosquitoes of all categories than did G.dubia per 24h: unfeds 5.1+0.1% v. 4.5 + 0.5%, blood‐feds 4.5 ± 0.3% v. 4.0 ± 0.5% and gravids 4.8 ± 0.4% v. 3.9 ± 0.5%. Possible relevance of these results to competetive displacement of G.dubia by H.frenatus is discussed.
Efficacy of acaricidal tags and pour‐on as prophylaxis against ticks and louping‐ill in red grouse
Authors: LAURENSON M. K. , HUDSON P. J. , McGUIRE K. , THIRGOOD S. J. , REID H. W.
Published: March 2008

Abstract This paper examines the efficacy of 10% lambdacyhalothrin‐impregnated plastic tags and a deltamethrin pour‐on preparation in protecting red grouse chicks from parasitism by ticks and subsequent infection with the louping‐ill virus. In 1995, ten red grouse hens (Lagopus lagopus scoticus) in a free‐living population in north‐east Scotland were fitted with lambdacyhalothrin‐impregnated plastic tags, glued to radio transmitters. Chicks of more than 10 days of age from a further ten untreated radio‐collared hens were caught and fitted with individual tags to the plagium. Both treatments significantly reduced tick burdens in the short term. The number of larvae and nymphs on chicks up to 45 days was less under both treatments than on control chicks and tagged chicks had fewer nymphs than chicks from treated hens. Nevertheless, treatments did not reduce viral infection rates nor increase survival to 10 weeks, possibly explained by incomplete treatment of tagged broods and/or direct or indirect mortality due to tags. In 1996 chicks in ten broods from hens with radio transmitters were individually treated at 14 days of age at a rate of lmg/kg of chick with a deltamethrin pour‐on preparation. This preparation significantly reduced the number of larvae and nymphs on grouse chicks 7–10 days after application below the number on untreated controls. At 20 days from application, however, only larval numbers were lower on treated chicks. Nevertheless louping‐ill virus infection prevalences were significantly reduced at 35 days of age and survival of chicks to 10 weeks increased.
Safety and efficiency conflicts in hydraulic architecture: scaling from tissues to trees
Authors: SPERRY JOHN S. , MEINZER FREDERICK C. , McCULLOH KATHERINE A.
Published: March 2008

Tree hydraulic architecture exhibits patterns that propagate from tissue to tree scales. A challenge is to make sense of these patterns in terms of trade‐offs and adaptations. The universal trend for conduits per area to decrease with increasing conduit diameter below the theoretical packing limit may reflect the compromise between maximizing the area for conduction versus mechanical support and storage. Variation in conduit diameter may have two complementary influences: one being compromises between efficiency and safety and the other being that conduit tapering within a tree maximizes conductance per growth investment. Area‐preserving branching may be a mechanical constraint, preventing otherwise more efficient top‐heavy trees. In combination, these trends beget another: trees have more, narrower conduits moving from trunks to terminal branches. This pattern: (1) increases the efficiency of tree water conduction; (2) minimizes (but does not eliminate) any hydraulic limitation on the productivity or tissue growth with tree height; and (3) is consistent with the scaling of tree conductance and sap flow with size. We find no hydraulic reason why tree height should scale with a basal diameter to the two‐thirds power as recently claimed; it is probably another mechanical constraint as originally proposed. The buffering effect of capacitance on the magnitude of transpiration‐induced xylem tension appears to be coupled to cavitation resistance, possibly alleviating safety versus efficiency trade‐offs.
Heterologous expression, and biochemical and cellular characterization of CaPLA1 encoding a hot pepper phospholipase A1 homolog
Authors: Seo Young Sam , Kim Eun Yu , Mang Hyung Gon , Kim Woo Taek
Published: March 2008

Phospholipid signaling has been recently implicated in diverse cellular processes in higher plants. We identified a cDNA encoding the phospholipase A1 homolog (CaPLA1) from 5‐day‐old early roots of hot pepper. The deduced amino acid sequence showed that the lipase‐specific catalytic triad is well conserved in CaPLA1. In vitro lipase assays and site‐directed mutagenesis revealed that CaPLA1 possesses PLA1 activity, which catalyzes the hydrolysis of phospholipids at the sn‐1 position. CaPLA1 was selectively expressed in young roots, at days 4–5 after germination, and rapidly declined thereafter, suggesting that the expression of CaPLA1 is subject to control by a development‐specific mechanism in roots. Because transgenic work was extremely difficult in hot peppers, in this study we overexpressed CaPLA1 in Arabidopsis so as to provide cellular information on the function of this gene. CaPLA1 overexpressors had significantly longer roots, leaves and petioles, and grew more rapidly than the wild‐type plants, leading to an early bolting phenotype with prolonged inflorescence. Microscopic analysis showed that the vegetative tissues of 35S:CaPLA1 plants contained an increased number of small‐sized cells, which resulted in highly populated cell layers. In addition, mRNAs for cell cycle‐controlled proteins and fatty acid catabolizing enzymes were coordinately upregulated in CaPLA1‐overexpressing plants. These results suggest that CaPLA1 is functionally relevant in heterologous Arabidopsis cells, and hence might participate in a subset of positive control mechanisms of cell and tissue growth in transgenic lines. We discuss possible biochemical and cellular functions of CaPLA1 in relation to the phospholipid signaling pathway in hot pepper and transgenic Arabidopsis plants.
Utility of impulse oscillometry in young children with asthma
Authors: Song Tae Won , Kim Kyung Won , Kim Eun Soo , Park Jung‐Won , Sohn Myung Hyun , Kim Kyu‐Earn
Published: March 2008

Impulse Oscillometry (IOS) was developed as a tool to measure lung function, and as it only requires passive cooperation, it has been successfully used in younger children. The aim of this study was to assess the utility of IOS compared to conventional spirometry for lung function measures in asthmatic Korean children aged 3 to 6 yrs. Total serum IgE levels, total eosinophil counts, and specific IgE levels were measured in 77 children with asthma and 55 control subjects. IOS and spirometry were performed in the children before and after bronchodilator administration. Asthmatic children significantly differed from control subjects in baseline resistance at 10 Hz and in their IOS‐assessed bronchodilator responses through a Δresistance at 5 Hz (mean, −27.4% vs. −13.1%; p = 0.002), 10 Hz (mean, −20.4% vs. −11.5%; p = 0.012), 20 Hz (mean, −16.4% vs. −9.4%; p = 0.016), and 35 Hz (mean, −17.2% vs. −10.2%; p = 0.020). Conventional spirometry did not show statistically significant findings. Asthmatic children significantly differed from control subjects in IOS‐assessed bronchodilator response through a Δresistance at 5 Hz, both in atopic children and in non‐atopic children. For atopic children, atopic asthmatic children (n = 58) also significantly differed from atopic controls (n = 30) in baseline resistance at 10 Hz, 20 Hz, 35 Hz and impedance and in IOS‐assessed bronchodilator responses through a Δ resistance at 10 Hz and 35 Hz. There were some significant correlations between bronchodilator responses of spirometric parameters and IOS parameters. IOS is useful diagnostic tool in early asthma development and might be a helpful objective outcome measure of early interventions.
Polyphenol oxidase can cross thylakoids by both the Tat and the Sec‐dependent pathways: a putative role for two stromal processing sites
Authors: Koussevitzky Shai , Ne’eman Emma , Peleg Smadar , Harel Eitan
Published: March 2008

Polyphenol oxidase (PPO; EC 1.10.3.2 or EC 1.14.18.1), a thylakoid‐lumen protein encoded by a nuclear gene, plays a role in the defense of plants against both herbivores and pathogens. Although previously reported to be a Tat (twin‐arginine‐dependent translocation) protein, the import of PPO by isolated chloroplasts was inhibited by azide, a diagnostic inhibitor of the Sec‐dependent pathway. Import of PPO inhibited thylakoid translocation of a Tat protein and did not affect translocation of Sec‐dependent proteins. In contrast, a pre‐accumulated iPPO competed with Sec‐dependent but not with Tat proteins. A previously reported second processing step in the stroma removes a twin‐Arg that is part of a ‘Sec‐avoidance’ motif in the thylakoid targeting domain of PPO. When the second processing site was mutated, the import of the resulting precursor showed Sec‐dependent characteristics. The PPO transit peptide could drive thylakoid translocation of a Tat protein in the dark. Azide inhibited the secretion of a PPO intermediate that lacks a twin‐Arg to the periplasm of Escherichia coli, but had no effect on the export of the intermediate containing the twin‐Arg. PPO is synthesized in plants in response to wound and pathogen‐related signals and it is possible that when the Tat pathway is unable to translocate adequate amounts of newly synthesized PPO, translocation is diverted to the Sec‐dependent pathway by processing the intermediate at the second site and removing the twin‐Arg.
Impact of Humidity on Temperature‐Induced Grain Sterility in Rice (Oryza sativa L)
Authors: Weerakoon W. M. W. , Maruyama A. , Ohba K.
Published: March 2008

High temperature‐induced grain sterility in rice is becoming a serious problem in tropical rice‐growing ecosystems. We studied the mechanism of high temperature‐induced grain sterility of different rice (Oryza sativa L) cultivars at two relative humidity (RH) levels. Four varieties of Indica and Japonica rice were exposed to over 85 % RH and 60 % RH at 36/30 °C, 34/30 °C, 32/24 °C and 30/24 °C day/night air temperatures from late booting to maturity inside sunlit phytotrons. Increasing both air temperature and RH significantly increased spikelet sterility while high temperature‐induced sterility decreased significantly with decreasing RH. Neither Indica nor Japonica rice types were superior to the other in the response of their spikelets to increased air temperature and RH. Increased spikelet sterility was due to increased pollen grain sterility which reduced deposition of viable pollen grains on stigma. Reduction in sterility with decreased RH was more due to decreased spikelet temperature than to air temperature. Thus the impact of RH should be considered when interpreting the effect of high temperature on grain sterility. Spikelet fertility was curvilinearly related to spikelet temperature. Grain sterility increased when spikelet temperature increased over 30 °C while it became completely sterile at 36 °C. The ability of a variety to decrease its spikelet temperature with decreasing RH could be considered as avoidance while the variability in spikelet sterility among varieties at a given spikelet temperature could be considered as true tolerance.
Root Nitrogen Remobilization and Ion Status of Two Alfalfa (Medicago sativa L.) Cultivars in Response to Salinity Stress
Authors: Mohammadi H. , Poustini K. , Ahmadi A.
Published: March 2008

In a pot experiment the responses of two alfalfa cultivars differing in salt tolerance were evaluated in terms of root nitrogen remobilization rates (RNRR) and their relationship with the ionic status of the plants. A split‐plot design with factorial treatments in three replications was used. Three levels of salinity stress with electrical conductivities (ECs) of 1.2, 7 and 12 ds m−1 were established in irrigation water by using tap water with and without NaCl. The average data taken from plant materials at three defoliations were used for statistical analysis. Each time, plant materials were harvested at the 10 % flowering stage and then 10 days later. From the results observed, it was found that alfalfa shoot growth is highly dependent on RNRR under salinity stress. However, the total N reserves within the roots do not appear to be a limiting factor. The high positive correlation coefficient between shoot K+/Na+ and RNRR (r = 0.77; P = 0.01) indicates that lower demands for N because of diminished metabolic activities within the shoot sink may have reduced the rates of root N utilization. Unlike in some other species, the shoot K+ concentration and contents of alfalfa plants were significantly reduced by increasing salt stress. However, a relatively suitable K+/Na+ ratio of 7.1 is maintained in the shoots at the second level of salinity, as lowering the rates of salt induced an increase in Na+ uptake (Na exclusion). The salt tolerance recognized in the Bami cultivar may be attributed to the 339 % increase in its selectivity rates of K+ over Na+ in ion transport from the soil to the shoots, as the shoot Na+ content did not increase with increasing salt levels.
Contents of Total Phenolics and Ferulic Acid, and PAL Activity during Water Potential Changes in Leaves of Maize Single‐Cross Hybrids of Different Drought Tolerance
Authors: Hura T. , Hura K. , Grzesiak S.
Published: March 2008

The aim of this study was to determine whether the resistance and/or sensitivity to drought stress, can be attributed to the level of phenolic compounds in the leaves of maize genotypes. The experiments were carried out on seedlings of three maize genotypes characterized by different levels of drought resistance. Experiments with three periods of drought were conducted (8, 11 and 14 days), to obtain plants with different levels of water potential in leaves, which induced changes in the total phenolic content and ferulic acid, and l‐phenylalanine ammonia‐lyase (PAL) activity. Only for the drought‐resistant genotype Tina, was the low water potential found to be correlated with the high level of the total phenolic content and ferulic acid, which is the main source of blue fluorescence emissions. Moreover, only for Tina were the highest intensities of blue fluorescence emission correlated with the low water potential in leaves. The phenolic compounds present in leaf tissues can protect the deeper situated mesophyll, by absorbing light reaching the leaf and transforming it into a blue fluorescence. Phenolic compounds can, in this way, function as photoprotectors limiting the excitation of chlorophyll during conditions of water deficit in leaves.
Influence of High Shoot and Root‐Zone Temperatures on Growth of Three Wheat Genotypes during Early Vegetative Stages
Authors: Tahir I. S. A. , Nakata N. , Yamaguchi T. , Nakano J. , Ali A. M.
Published: March 2008

High temperatures, whether of shoot or root, are reported to affect shoot and root growth of various plant species. The scanty information available on the differential response of wheat genotypes to high shoot and root‐zone temperatures triggered this investigation to study the response and adaptation of shoot and root growth of three wheat genotypes to high shoot and root‐zone temperatures during early growth stages. Three wheat genotypes; Fang (heat tolerant), Siete Cerros (heat sensitive) and Imam (recent cultivar adapted to a hot irrigated environment) were grown in soil and hydroponically. Three shoot/root‐zone temperatures (23/23, 23/35 and 35/35 °C for the soil experiment and 22/22, 22/38 and 38/38 °C for the hydroponic experiment) were applied at three‐leaf growth stage. High root‐zone temperature alone or combined with high shoot temperature reduced xylem sap flow rate, root dry weight, root length and root/shoot ratio. Unexpectedly, shoot fresh and dry weights and relative growth rate (RGR) were not significantly affected by the high root‐zone temperature except for the susceptible genotype, Siete Cerros, after prolonged exposure in the hydroponic experiment. In contrast, high shoot/root‐zone temperature significantly reduced shoot fresh and dry weights from as early as the first week of the hydroponic experiment. The 38/38 °C treatment also caused significant reduction in RGR and net assimilation rate during the first 2 weeks, but no significant differences were found during the last 2 weeks compared with 22/22 °C. Interesting responses were observed among genotypes in terms of shoot and root dry weights and root/shoot ratio at 38/38 °C treatment. The heat‐sensitive Siete Cerros showed the least reduction in these traits during the first 2 weeks while the heat‐tolerant Fang and Imam responded by greatly reducing their shoot and root weights. The situation was almost reversed with the duration of treatments such that Siete Cerros became the most affected genotype while Fang and Imam were better adapted to high shoot/root‐zone temperature. Specific root weight was the exceptional trait that increased under high temperature treatments. Results indicate that despite the reduction in root length and weight observed under high root‐zone temperature, shoot growth was not much affected suggesting that the use of suitable cultivar coupled with proper management could alleviate most of high root‐zone temperature effects during early growth stages.