Mean Number Of Eggs Research Articles

Evaluation of F3 generations of the hybrid crosses between vegetable and field cowpeas and their parents for resistance to the cowpea bruchids (Callosobruchus maculatus (F))

An evaluation of crosses between vegetable and field cowpea for resistance to the cowpea Bruchids, [ Callosobruchus maculatus (F)], was carried out at the Enugu State University of Science and Technology, Enugu southeastern Nigeria. There was a significant difference in the field infestation of the cowpea lines by C. maculatus . AD-36-WB had the highest percentage field infestation by the insect pest, whereas, AE—36-C X AN-16-D, and AN-14-D were free from the field infestation by the pest. Vegetable cowpea lines tested had some levels of resistance to the cowpea Bruchid and the gene responsible for the resistance were successfully transferred from vegetable cowpea to the susceptible field cowpea by cross-breeding techniques. No vegetable cowpea tested had complete resistance to the cowpea bruchid, however, they had lower susceptibility than the field cowpea tested. Reduction in the relative susceptibility of the cowpea to C. maculatus was achieved by cross breeding field cowpea with vegetable types. For instance, in crosses between AD-36-W (field cowpea) and AE-36-C (vegetable cowpea), AD-36-WB (field cowpea) and AN-14-D (vegetable cowpea), AD-36-W (field cowpea) and AE-36-F (vegetable cowpea), AD-36-WB (field cowpea) and AE-36-C (vegetable cowpea), AN-14-D and AE-36-F reduced susceptibility of AD-36-W and AD-36-WB to C. maculatus from 63.59% to 51.09%, 68.46% to 59.09%, 63.59% to 47.38% and 68.48% to 38.84% respectively. Also, gene responsible for susceptibility to the storage insect pest were successfully transferred from field cowpea to the vegetable cowpea through cross-breeding techniques. A cross between two vegetable types namely; AE-36-C and AN16-D had the least susceptibility level of 24.32%. There was a significant difference in mean number of eggs laid per cowpea line with AD-36-WB recording the highest mean number of 134.75 eggs and AE-36-F recording the least mean number of 4.75 eggs. There was also a significant difference in the percentage adults emergence per cowpea line with AD-36WB having the highest percentage of 68.46% adults, and AE-36-C X AN-16-D having the least percentage of 24.32% adults. The result of the experiment also showed a significant difference in mean longevity of female adults reared from cowpea lines with those reared from AD-36WB X An-14-D, and AE-36-C having the highest mean longevity of 14 days each whereas those from AD-36WXAE-36-C had the least mean longevity of 5.6 days. Also, there was a significant difference in mean testa thickness of the seeds tested with AE-36-C having the highest mean testa thickness of 0.20mm, whereas AD-36-WB had the least mean testa thickness of 0.02mm. However, there was no correlation between either testa thickness or moisture content and levels of infestation by the storage insect pest. Again, there was a significant difference between mean weight loss of seeds tested after infestation by C. maculatus , with AD-36WB recording the highest mean weight loss of 0.38g, whereas AE-36-C and AE-36-F, had the least mean weight loss of 0.07g. There was a positive correlation between the weight loss of the adult C. maculatus and the weight (g) of the seeds from which the insect pest was reared (r = 0.03). Key words: Cowpea lines, cross-breeding, Callosobruchus maculatus , resistance, susceptibility

Large-scale Anopheles arabiensis egg quantification methods for mass-rearing operations.

BackgroundThe success of the sterile insect technique relies, among other things, on the continuous release of over flooding numbers of sexually competitive sterile males into the target area. To produce sufficiently large quantities of sterile males, rearing protocols need to be optimized including the development and validation of a standardized egg quantification method.MethodsBatches of 1000 freshly laid eggs collected from standard rearing cages were counted, gently dried under laboratory conditions (27 ± 1 °C, 75 ± 5 % RH) and combined so that 1000–8000 eggs were weighed, to calculate the correlation between weight and number. The actual counted egg number and the egg number estimated by weighing were further compared for samples of 1000, 3000 and 4000 eggs collected from both standard and mass-rearing cages. The effect of drying, brushing and weighing on egg hatch rate was evaluated in three samples each of 1000 fresh and 1000 dried eggs, and in batches of 1000, 3000 and 4000 dried eggs. Pupal production and adult life history traits were assessed for dried eggs hatched and reared in mass-rearing trays. Expected egg numbers and actual observed mean egg numbers were compared after gentle drying, and after applying a rapid drying method exposure to wind speed of 1.8 m/s for 30 min.ResultsA significant positive relationship between the number of dried eggs and egg weight was observed and the equation ‘Weight (mg) = (0.00399 × Number of counted eggs) + 0.536 was derived. The actual counted mean egg number and the egg number estimated by weighing were similar for samples from small rearing cages but significantly lower for samples of 3000 and 4000 egg samples collected from mass-rearing cages. No negative effect of the drying, brushing and weighing process on egg hatch rate was observed. No significant difference was observed in any life history trait between adults reared from dried or from fresh eggs up to twenty-one days post emergence. The mean number of eggs counted from a given replicate’s weight was significantly higher for egg batches fast dried with a suction device compared to those dried with a gentle drying method (fast: 1075 ± 9, gentle: 1024 ± 7).ConclusionAn equation has been derived to allow accurate quantification of dried Anopheles arabiensis eggs based on weight, enabling more accurate quantification of eggs for consistent larval rearing density to be achieved. Eggs can be dried for weighing in a manner which does not impair the quality of resulting adults.

Anidación y conservación de la tortuga lora (Lepidochelys olivacea) en playa Drake, península de Osa, Costa Rica (2006 a 2012)

Desde 2006 a 2012, la anidación de la tortuga lora (Lepidochelys olivacea) fue monitoreada en bahía Drake, un enclave reconocido internacionalmente por su excelente oferta eco-turística que se localiza en la región noroeste de la península de Osa. Sorprendentemente, esta área dispone de playas de anidación solitaria de tortuga lora que han permanecido casi desadvertidas hasta fechas recientes. Durante este periodo de monitoreo, 958 nidos fueron registrados en playa Drake (promedio anual: 136.9; densidad: 3.80 nidos/100m de playa), de los cuales 363 (37.9%) fueron reubicados a un vivero. Antes de 2006, la pérdida anual de nidos fue superior al 85% debido al saqueo en playa; desde 2006, el porcentaje del saqueo de nidos se mantuvo en un promedio del 10.1%. Además, un total de 335 hembras fueron identificadas con placas metálicas; el promedio de la longitud curva del caparazón fue de 66.1cm; el promedio del ancho curvo del caparazón fue de 70.2cm, y el tamaño promedio por nidada fue de 96.3 huevos. El promedio del éxito de eclosión para los nidos reubicados en vivero fue de 79.2%, y más de 61 000 neonatos fueron liberados al mar durante este periodo. Este proyecto es un ejemplo de una iniciativa exitosa de conservación, eco-turismo y desarrollo comunitario.

Fecundity of Palaemon carteri (Gordon, 1935) (Crustacea: Decapoda: Palaemonidae) from the Eastern Amazon, Brazil

Palaemon carteri is one of the most common palaemonid shrimps in the Amazon region. The objective was to analyze the fecundity of P. carteri from the Eastern Amazon. The specimens derive from 11 streams, which were sampled in 2011. Using a stereomicroscope and an ocular micrometer, the total length, cephalothorax length, rostrum length, and abdomen length of ovigerous females were obtained. The eggs were counted, and their major and minor axes were measured. Based on eye pigmentation in the eggs, two groups of females were sorted according to the development stage of the embryos. A total of 65 ovigerous females were analyzed, with mean total length of 26.11 ± 1.36 mm (range: 23.00 to 29.16). Regarding body size, there was no difference between the two groups of females. The mean egg number was 18 (range: 4 to 29). Females with eggs in the initial development stage had a higher number of eggs (mean: 20 ± 3.8) than the ones in a more advanced stage (mean: 16 ± 5.1). On the other hand, the latter presented a higher mean volume (0.91 ± 0.27 mm3). Palaemon carteri has low fecundity compared with other palaemonid species, and egg loss during incubation seems to favor the survival chances of the remaining embryos.

Captive Propagation, Reproductive Biology, and Early Life History ofEtheostoma wapiti(Boulder Darter),E. vulneratum(Wounded Darter), andE. maculatum(Spotted Darter)

Abstract Reproductive biology and early life-history data are important for understanding the ecology of fishes. In 2008, we conducted captive propagation studies on 3 species of darters of the subgenus Nothonotus: Etheostoma wapiti (Boulder Darter), E. vulneratum (Wounded Darter), and E. maculatum (Spotted Darter). The length of spawning period and associated range of water temperatures for the Wounded Darter exceeded that of the Spotted Darter and Boulder Darter. The mean number of eggs produced per female was lowest for Boulder Darter and highest in the Wounded Darter. The Boulder Darter had the highest percent of eggs hatched, the lowest percent larval to juvenile stage survivorship, and the lowest mean number of juveniles produced per female. Egg diameters at deposition and prior to hatch were smallest for the Spotted Darter. If reproductive biology and early lifehistory information from captive fishes represent that of wild populations, then the data obtained during this study are relevant to develo...

Oviposition periodicity, egg morphology and life history of large cabbage moth Crocidolomia pavonana population in Samoa

A study on the biology and behaviour of the Samoan population of Crocidolomia pavonana was carried out through a series of experiments. The study showed that C. pavonana completes its life cycle in 24-35 days. Female emerge, mate and oviposit (as egg mass) during the scotophase. The average size of egg mass was 9.0 ± 0.48 mm2 and the mean number of eggs oviposited were significantly (PC. pavonana oviposits small egg masses. This information could be used to develop effective pest management using the recently identified egg parasitoid Trichogramma chilonis.

Role of photoperiod in the development and reproduction of Harmonia axyridis (Coleoptera, Coccinellidae)

ABSTRACTTo improve the laboratory mass rearing and the winter greenhouse use of the multicoloured Asian lady beetle Harmonia axyridis (Pallas) (Coleoptera, Coccinellidae), the effects of photoperiod on the development and fecundity of H. axyridis were investigated at 20°C and photoperiods ranging from 0L:24D to 24L:0D. We foun'd photoperiod to significantly affect the pre-imaginal development and reproduction of H. axyridis. The development of the pre-imaginal stage was significantly faster at shorter photoperiods (0–14 h) than at longer ones (16–24 h). The proportion of females laying eggs within the first 30 days after eclosion, the mean number of eggs per ovipositing female, and the long axial length of the first oocyte were all lower at shorter photoperiods (6–12 h) than at longer ones (14–24 h). These results suggest that adult H. axyridis may encounter problems in preying and reproducing in the winter conditions of unheated and unilluminated greenhouses in areas with temperatures lower than 20°C and day lengths shorter than 12 h.

Environmental contamination with Toxocara eggs and seroprevalence of toxocariasis in children of northeastern Poland.

Toxocariasis is a worldwide distributed zoonotic disease. Soil contaminated with Toxocara eggs appears to be the main source of infection for humans. The aim of our study was to estimate the environmental contamination with Toxocara eggs in public areas in northeastern Poland followed by the assessment of seroprevalence of toxocariasis in the children's population inhabiting the areas. A total of 168 soil samples were collected in June and September from public areas, and 28 from patients' residences. They were all examined for Toxocara eggs using the centrifugal flotation technique. Two-step serological tests comprising enzyme-linked immunosorbent assay (ELISA) and Western blot (WB) were performed in 190 children aged 2-17 without any symptoms of toxocariasis. The positive samples accounted for 36 and 32 % in the urban area, 39 and 18 % in the suburbs, and 39 and 46 % in parks, for June and September, respectively. All the sites located near the patients' residences with confirmed persistent toxocariasis were found contaminated with Toxocara eggs. A significant drop in the mean number of eggs was noted in the suburbs after summer (0.64 vs 0.18, p < 0.05). High and constant contamination was documented in soil from urban sandboxes and parks. The overall seroprevalence in children tested for toxocariasis was 4.2 % as determined by ELISA and WB (3.0 % in preschool children and 7.7 % in school children). The current study revealed high contamination of public areas in northeastern Poland with Toxocara eggs as well as marked seroprevalence in asymptomatic children. There is an urgent need to introduce and promote preventive health measures to limit spread of toxocariasis.

The incidence and economic impact of the Escherichia coli peritonitis syndrome in Dutch poultry farming

The incidence and economic impact of the Escherichia coli peritonitis syndrome (EPS), characterized by acute mortality, were estimated in chicken egg-producing farms in the Netherlands in 2013. The incidence was significantly higher (P < 0.05) in the meat-sector (35% affected farms) compared to the layer-sector (7% affected farms). In consumption egg-producing farms EPS occurred on 12% of the free range and organic farms, while it was found on 1% and 4% of the cage and barn farms, respectively. Data from four layer and two broiler breeder flocks with EPS were used to estimate the overall economic impact of the disease. Mean numbers of eggs lost were 10 and 11 per hen housed (phh), while mean slaughter weight loss was 0.2 and 0.5 kg phh in the four layer and two broiler breeder flocks, respectively. Total losses including costs of destruction of dead hens, compensated for reduced feed intake due to a smaller flock size, ranged from €0.28 phh (cage farms) to €9.75 phh (grandparent farms) in the layer-sector and from €1.87 phh (parent farms) to €10.73 phh (grandparent farms) in the meat-sector. Antibiotics against EPS were given often and repeatedly especially in the meat-sector. Including the costs of antibiotics, total losses were estimated at €0.4 million, €3.3 million and €3.7 million for the layer-sector, the meat-sector and poultry farming as a whole, respectively. Research focusing on the prevention and treatment of EPS is justified by its severe clinical and economic impact.

The status of Indigenous chicken production systems in the Lango sub region of Northern Uganda

This study was conducted in four districts in Lango sub region of Northern Uganda. A total of 320 households (HH) from 32 villages (eight villages from each district) were included in the study. The objectives were to assess the flock characteristics, production, productivity and related constraints of village chicken production in Lango sub region. A formal survey, using structured questionnaires integrated with participatory rural appraisal techniques relevant to rural chicken production system, was applied. Study districts and corresponding market sheds differed significantly in the flock characteristics. The mean number of Matured chicken, Hen/pullets, Cocks, and Chicks per household was 7.4±0.22, 5.4±0.17, 2.2±0.09, 8.5±0.37 respectively, with a male to female ratio of 1:2.9. Purchase and exchange for labor were the main sources of foundation stock while hatching was the main sources of replacement stocks. Mean egg laying performance of hens was 17, 21 and 25 eggs for the first, second and third and higher clutches, respectively. Mean clutch number was 2.6±0.06 per year. The mean number of eggs set per bird was 13.5±0.19. Hatching rate was 74.6±0.86 ranging from 35.3-90% (n=320). High mortality of chicks (average survival rate of 51.6±6.3%, ranging from 12-71%.) were reported and occurred between hatching and the end of brooding at 8 weeks of age. About 86.5% of the eggs produced are incubated in order to replace birds that die. This makes the reproduction for replacement as the main focuses of chicken keepers. It is concluded that village chicken production is part of a balanced farming system and that there exists considerable opportunities for changing the inefficient system using the available animal and other resources.

Polymerase Chain Reaction: A Better Method for Diagnosing Chronic Schistosoma mansoni Infections.

For more effective diagnosis of the acute and chronic stages of Schistosoma mansoni infection in humans, the polymerase chain reaction (PCR) technique was compared with the Kato-Katz method. A total of 150 stool samples were collected from inpatient and outpatient clinics at the Department of Tropical Medicine, Minia University Hospital, Egypt. Three groups of patients, 50 with acute intestinal schistosomiasis, 70 with chronic intestinal schistosomiasis and 30 normal healthy controls were studied. Stool samples were analyzed by PCR and the Kato-Katz method. The mean number of eggs per gram of feces was 4.6 when estimated by the Kato-Katz method in positive stool samples from acute schistosomiasis cases but only 1.7 in chronic cases. In acute intestinal schistosomiasis, 15 and 45 out of 50 cases were positive by Kato-Katz and PCR, respectively. In the chronic intestinal schistosomiasis cases, 6 and 68 out of 70 cases were positive by the Kato-Katz and PCR methods, respectively. We conclude that PCR appears to be an effective diagnostic technique for S. mansoni infection, especially where a low worm burden exists, such as in chronic cases.

Reproductive Cycle and Fecundity in Natural Population of Edible Freshwater Crab, Oziothelphusa senex senex (Fabricius, 1798) (Decapoda: Brachyura)

Rapid growth rate, high meat content, excellent palatability and resistance to white spot virus favored the culture of crab species in aquaculture industry. This study examined the natural reproductive cycle of edible fresh water crab Oziothelphusa senex senex by monthly measurement of ovarian index and histological examination of the gonads of the animals and determination of berried and young-one-bearing females collected monthly. The number of berried and young-one-bearing females was significantly higher in September-October. However, a small number of ovigerous and young-one bearing females were observed throughout the year. We also observed a breeding peak in September-October using ovarian index as marker. Within study catchments, mean number of eggs and young ones was 130 and 120 during September and 132 and 118 in October. The number of eggs spawned in the smallest (17 g body weight) crab is 80 and the largest (44 g body weight) crab is 140. We also observed a positive correlation between the numbers of eggs spawned and body weight. Surprisingly, no correlation was found between the breeding cycle and the environmental factors such as temperature, photoperiod and rain fall. The lesser dependence on climatological factors for the completion of reproduction in the crab indicates greater potential of this species for crab fishery.

Procedure for Maturation and Spawning of Imported shrimp Litopenaeus vannamei in Commercial Hatchery, South East Coast of India

The reproductive performance of the broodstock was assessed at each stage of the maturation and spawning process. Measures of maturation rate, spawning rate, fecundity, hatch rate and nauplii production rate were obtained. The reproductive performance was found for the imported Specific Pathogen Free (SPF) broodstock from Shrimp Improvement system (SIS), Florida, USA. The no.of spawning, eggs quantity, fertility, hatching rate and nauplii production were lowest in 1st to 3rd spawning when females were 7 months old and increased from 4th spawning rate onwards. As the size of females increased from 30 g to 52 g the mean number of eggs per spawning increased from 150,000 to 442,000. Although female body weight was increasingly larger through the study period and the larger females would be expected to produce more eggs per spawning and hatching. The hatching rate was increased from 3rd spawning onwards. The nauplii production rate (NPR), which is a function of egg production and hatching rate, showed a significant increasing from 48% to 96%. In 10th spawning all the activities were increased. This information can be used to select broodstock for hatchery production.

Does age modify the predictive ability of anti-Müllerian hormone?

Aim: Anti-Mullerian hormone (AMH) is one of the best markers of ovarian reserve, but it does not predict pregnancy well. Age influences oocyte quality and therefore in vitro fertilization (IVF) outcome. Our aim was to test the predictive ability of AMH for clinical outcome in different age categories. Materials and Methods: Retrospective analysis based on IVF data obtained in a single practice between January 1, 2014, and December 31, 2014. Three AMH categories were evaluated (low: 3.5 ng/ml). IVF treatment outcomes were compared in 3 age categories ( 40 years) based on AMH values. Main outcome parameters were oocyte yield, gonadotropin dose/oocyte collected, and ongoing pregnancy rate (OPR). Data on miscarriage rates were analyzed as well. Results: 318/384 cycles were included. Oocyte yield was higher in the high and medium AMH groups when compared to the low AMH category: 9.5 ± 5.6 and 8.2 ± 3.2 versus 4.8 ± 3.1, P 3.5 ng/ml group. In the 40 years old groups, the mean number of eggs collected was significantly lower in the P P = 0.23) or separately based on AMH results. In the low AMH group, those with high follicle stimulating hormone (FSH) as well (>10 IU/l) had significantly lower OPR however (37% vs. 17.9%, P = 0.02). Conclusions: Low ovarian reserve (AMH < 1.1 ng/ml) is associated with low egg yield and need for higher dose gonadotropin in all studied age groups. It is, however, not predictive of OPR. Those with both low AMH and high FSH had the least chance to achieve an ongoing pregnancy.

Biological traits of Cyzicus grubei (Crustacea, Spinicaudata, Cyzicidae) in south-western Iberian Peninsula

2 In this study, characteristics of the biology of the spinicaudatan Cyzicus grubei were determined from a population in a temporary pond in the south-western Iberian Peninsula from January 2011 to July 2011. The results indicated the existence of a single cohort for the duration of the flooding period. Non-ovigerous females and males were present in the pond throughout the study period. However, ovigerous females were present from mid-April to early July. Males had valves significantly larger and higher than females. The relationship between the valve length and the valve height showed positive allometry in males and negative allometry in females and the whole population (mature and immature individuals). The smallest mature male was 8.13 mm in valve length, whereas the smallest ovigerous female was 8.21 mm in valve length. Females outnumbered males in winter and early spring, and males were more abundant in late spring and early summer. The mean number of eggs on ovigerous females was 574.74±245.29, ranging from 241 to 1068 eggs/female. The number of eggs was linearly correlated with the valve length of the female.

Interaction of Static Magnetic Fields (SMF) with Biology of Tetranychus urticae Koch (Acari)

A laboratory experiment was conducted to study the effects of Bio-assay of the economic mite; Tetranychus urticae Koch by the levels of static magnetic field forces. Completely randomized experiment with three replicates was designed. Similar groups of eggs of T. urticae were exposed to the odd numbers of magnets ; 1,3 and 5 units ( 0.14- 4.0 ml.t. ) and even numbers of magnets; 2,4 and 6 ( 2.6-4.24 ml.t.). Check was left without magnetizing. The observations included, egg hatchability percentage, incubation period, life cycle, longevity, life span, survivability, mean number of eggs/ female and sex ratio of the 1 generation. Results showed that there was a linear negative relationship between the force of magnetic field and the percentage of egg hatchability. Hatching eggs were decreased from 100 % in the check to 90.3% in 6 magnet unit's treatment. Also mean number of eggs and longevity decreased from 4.0 eggs & 16.9 days to 2.3 eggs & 11.4 days; while incubation period and life cycle were prolonged depending on the number of magnet pieces from 7.0 & 15.7 days to 8.4 & 12.0 days, respectively of the above-mentioned magnets exposure.

Spatio-temporal factors influencing the occurrence of Syngamus trachea within release pens in the South West of England

Syngamus trachea is a pathogenic tracheal nematode that causes syngamiasis in wild and game birds, especially when birds are managed at high densities. Despite its pathogenic nature, very little is known about its epidemiology and relationship with ambient temperature and humidity. The spatial and temporal modelling of disease was undertaken on two pheasant estates within the South West of England from April 2014 to August 2014. Significant differences between the mean numbers of eggs per gram of soil were identified between pens at both site 1 and site 2 but did not differ significantly between sites. Egg abundance was significantly associated with soil moisture content, with greater egg survival between years in pens with higher average volumetric soil moisture content. Previous years stocking density and pen age were also associated with greater egg survival between years with more eggs being recovered in pens with greater stocking densities, and pens that had been sited longer. The greatest model to explain the variation in the numbers of eggs per gram of soil per pen was a combination of soil moisture content, stocking density and pen age.Larval recovery differed significantly between sites. Larval abundance was significantly and positively associated with temperature and relative humidity at site 1. Similarly, temperature and humidity were also positively and significantly associated with larval abundance at site 2. Rainfall did not influence larval recovery at either site 1 or site 2. The model with the greatest ability to explain larval abundance at both sites, was a combination of temperature, humidity and rainfall. Infection status (positive faecal egg counts) was significantly and positively associated with larval abundance at both sites, but rainfall was only positively associated at site 1. Temperature and humidity were positively associated with infection status at site 2, but not at site 1. The present study highlights the influence of climatic variables on both egg survival and larval abundance, and could therefore be used to develop more targeted treatment strategies around periods of higher disease risk. The frequent use of release pens is a clear factor in the epidemiology of syngamiasis, and it is recommended that pens be rested and/or rotated in order to reduce infection pressure in subsequent flocks.

Potencial inseticida de óleos de origem vegetal sobre Grapholita molesta (Busck) (Lepidoptera: Tortricidae)

Em decorrência do estudo das interações químicas entre insetos e herbívoros, e do avanço da pesquisa fitoquímica, é conhecida ampla variedade de produtos naturais com potencial inseticida. Grapholita molesta (Busck) (Lepidoptera: Tortricidae), mariposa-oriental, é uma das principais pragas do pessegueiro, danificando brotações e frutos. O objetivo do presente estudo foi verificar a mortalidade, atratividade e deterrência de óleos vegetais em G. molesta. Ovos e pupas de insetos provindos de criação artificial foram imersos nos óleos essenciais de Elionurus muticus (Spreng.) Kuntze e Cymbopogon winterianus Jowitt ex Bor nas concentrações de 0,25%, 0,5%, 1% e 0,5%, 1%, 5%. Os testes de atratividade foram realizados em olfatômetro do tipo "Y". A deterrência à oviposição foi testada em gaiolas sem escolha e de dupla escolha. O óleo de E. muticus aplicado em ovos de G. molesta nas três concentrações causou mortalidades maiores que 30%, diferindo significativamente dos controles (p&lt;0,05). A mortalidade causada pelo óleo de citronela foi em torno de 70%, significativamente superior ao controle (p&lt;0,01). O óleo de citronela aplicado a 1% em pupas causou mortalidade de 99,8%. No teste com o olfatômetro, não houve atratividade dos adultos para nenhum dos óleos. A média de ovos no substrato com o tratamento (0,33±0,33), foi significativamente menor que no controle (7,3±0,88) (p&lt;0,01), indicando deterrência à oviposição.

Fecundity Reduction in the Second Gonotrophic Cycle ofCulex pipiensInfected with the Apicomplexan Blood Parasite,Hepatozoon sipedon

Fecundity reduction is a well-recognized phenomenon of parasite infection in insects. Reduced production of eggs might increase longevity of a host and release nutrients to both host and parasite that would otherwise be used for oogenesis. The objective of this study was to assess effects on fecundity caused by Hepatozoon sipedon, an apicomplexan blood parasite of snakes, in its invertebrate host, the mosquito Culex pipiens. In the first gonotrophic cycle, the mean number of eggs laid by mosquitoes infected with H. sipedon did not differ significantly from those laid by uninfected mosquitoes. However, in the second gonotrophic cycle infected mosquitoes laid significantly fewer eggs than did uninfected mosquitoes, and fecundity was reduced by 100% in mosquitoes with parasite burdens of more than 60 oocysts. There was a significant negative correlation between parasite burden, or the number of oocysts, and the number of eggs produced in the second gonotrophic cycle. Significantly fewer viable larvae hatched from eggs laid by infected compared to uninfected mosquitoes in the second gonotrophic cycle. These data indicate that fecundity reduction occurs in this system, although the physiological mechanisms driving this phenotype are not yet known.

Assessment of Chicken Production under Farmers Management Condition in East Gojam Zone, Amhara Regional State, Ethiopia

The survey was conducted in Eastern Gojjam Zone of Amhara regional state, North Ethiopia from January to June, 2013 to generate base line information on chicken production under farmer’s management condition. Of total, 83% of respondents practiced free ranging type chicken production system with conditional feed supplementation and frequent water supply. Despite the largest concern was given for female households, males also involved in chicken management activities aiming for household consumption and income generation. The mean flock size per household was found to be 13 and 5 for local and crossbred chickens, respectively. Almost all farmers in the tested districts provided night shelter for their chickens, and majority (91%) of them have experience of culling undesired chicken from the flock. From this study, the mean number of eggs laid was 18 eggs per/hen/clutch. Most chicken keepers in the study area had experience of selecting and incubating eggs for hatching using broody hens as a sole means of natural incubation. The average number of eggs set for incubation was 13 per broody hen, from which relatively fair number (83%) of chicks were hatched and 67% were grown well. Seasonal disease outbreak (100%) followed by predators (89%) was considered the largest threat to chicken production. Moreover, traditional management (83%), limitation of improved breed availability and lack of extension and chicken health services (86.7%) were the major constraints of chicken production in the study area. Therefore, holistic extension services such as applying breed and management improvement methods, besides to supplying chicken health service strategies are highly recommended in the study area for further improvement of chicken production under farmer’s management condition.