Search

Western corn rootworm, Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae), is a serious pest of corn and is currently managed with corn hybrids that produce insecticidal proteins derived from the bacterium Bacillus thuringiensis (Bt). Bt corn kills rootworm larvae and reduces larval feeding injury to corn roots. The Bt protein Gpp34/Tpp35Ab1, previously named Cry34/35Ab1, has been widely used in transgenic Bt corn for management of western corn rootworm, and field-evolved resistance has been found in some populations. In the United States, the refuge strategy is used to manage Bt resistance, with refuges of non-Bt host plants serving as a source of Bt-susceptible individuals, which in turn reduce the frequency of homozygous resistant individuals within a population. As such, the dominance of resistance strongly influences resistance evolution, with faster evolution of resistance when resistance is not recessive. Additionally, selection for resistance by a Bt crop leads to the accumulation of resistance alleles within refuge populations, thereby reducing the capacity of refuges to delay resistance. However, fitness costs can remove resistance alleles from refuge populations and preserve the dynamic of refuges producing Bt-susceptible genotypes. Bt-susceptible and Gpp34/Tpp35Ab1-resistant western corn rootworm were used to quantify the inheritance and fitness costs of resistance. We found that Gpp34/Tpp35Ab1 resistance was not recessive and had the accompanying fitness costs of slower developmental rate to adulthood and lower egg viability. This research will help improve insect resistance management by providing a better understanding of the risk of western corn rootworm evolving resistance to transgenic corn that produces Gpp34/Tpp35Ab1.

Field-evolved resistance to Cry3Bb1 corn by western corn rootworm, Diabrotica virgifera virgifera LeConte (Colleoptera: Chrysomellidae), has been reported in field populations in Iowa, Illinois, Nebraska, and Minnesota. Inheritance and fitness costs associated with Cry3Bb1 resistance have been determined for non-diapausing laboratory strains of western corn rootworm with either laboratory-selected resistance or field-derived resistance. However, information on inheritance and fitness costs of Cry3Bb1 resistance in the diapausing field populations is lacking. In this study, we determined the inheritance of Cry3Bb1 resistance for four diapausing field strains of western corn rootworm using plant-based bioassays. We also determined the fitness costs for eight diapausing field populations in a greenhouse experiment. We found that Cry3Bb1 resistance was an autosomal trait and that the inheritance of resistance was mostly non-recessive; however, there was some variation in the dominance of Cry3Bb1 resistance. We did not find evidence of fitness costs affecting survival to adulthood, developmental rate, or adult dry mass. However, we did detect a fitness cost affecting adult size. The results of this study will add to the current understanding of field-evolved resistance to Cry3Bb1 corn by western corn rootworm and help in developing better strategies to manage resistance.

Western corn rootworm, Diabrotica virgifera virgifera LeConte, is a serious pest of corn and is often managed with transgenic corn producing insecticidal toxins from the bacterium Bacillus thuringiensis (Bt). This pest has developed field-evolved resistance to all commercially available Bt traits, beginning with Cry3Bb1 in 2009. Fitness costs may accompany Bt resistance, where individuals with alleles for Bt resistance have reduced fitness on non-Bt corn compared to Bt-susceptible individuals. In conjunction with non-Bt refuges, fitness costs can delay the evolution of Bt resistance. Importantly, ecological factors may affect the presence and magnitude of fitness costs. For western corn rootworm, available data suggest that fitness costs of Bt resistance may be present in some cases. Using two Cry3Bb1-resistant western corn rootworm strains (Hopkinton and Cresco), a fitness-cost experiment was performed by rearing rootworm in the absence of Bt for six generations to test for fitness costs of Cry3Bb1 resistance and the effect of larval rearing density on fitness costs. Fitness costs were detected for both strains; however, strains were still resistant to Cry3Bb1 corn at the end of the experiment. Cresco experienced a greater loss of resistance at low versus high density, but no effect of density was detected in Hopkinton. Our study shows that fitness costs can accompany Bt resistance in western corn rootworm and may be more pronounced under low larval density. Even though fitness costs were present, it appears that rootworm populations may remain resistant to Cry3Bb1 corn for years after resistance has evolved.

Introduction: Uveitis is an inflammatory condition of uvea of eye. It is a sight threatening condition, so accurate and timely diagnosis and treatment is required. Acute anterior uveitis is characterised by eye pain or photophobia, circumlimbal redness and anterior chamber cells and flare. Methods: This is a cross-sectional descriptive hospital record-based study based on data record in eye department of a tertiary care level centre in Kathmandu, Nepal. All cases of anterior uveitis presented to our OPD over one-year duration (December 2017- November 2018) were enrolled. Age, sex, co-morbidities and profile of uveitis like slit lamp findings were recorded. Results: Total 52 cases of acute uveitis were observed during the study period. There were total 34 males and 18 females with eye involvement. Age group of the patients ranged from 19 to 79 years with median age of 36 years. Forty eight cases (92.3%) had unilateral involvement whereas only four cases (7.7%) had bilateral involvement. Keratic precipitates were seen in 44 patients. Majority of the patients had good vision; 65.4% in right eye and 69.2% in left eye. Conclusions: Most of the anterior uveitis occur in male in third and fourth decade. The most common complaints of the patient were decreased vision, eye pain and red eye.

Lygus hesperus Knight (Miridae: Hemiptera), a key pest of cotton in the United States, is a highly polyphagous insect. Upland cotton (Gossypium hirsutum L. var. hirsutum) and alfalfa (Medicago sativa L.) are two major field crop hosts of Lygus hesperus in the Texas High Plains. While alfalfa is considered a source of Lygus in cotton, Lygus intercrop movement behavior has not been fully characterized in cotton-alfalfa systems. Understanding the intercrop movement behavior of Lygus may facilitate better decision-making for Lygus management in these crops. A series of studies including a mark-release-recapture study and season-long field monitoring of Lygus were conducted in the Texas High Plains, USA. Season-long field marking and monitoring of Lygus intercrop movement revealed bidirectional Lygus movement and confirmed that Lygus preferred alfalfa over cotton. Net movement of Lygus between cotton and alfalfa was influenced by cotton phenology. A “two-crop/two-marker” field-marking and monitoring approach was successfully applied in characterizing Lygus seasonal intercrop movement. This approach can be used to study the effect of various crop management practices on Lygus intercrop movement and is applicable to other pests and cropping systems.

Background Transgenic crops producing insecticidal toxins from the bacterium Bacillus thuringiensis (Bt) are widely planted to manage agricultural insect pests. However, widespread adoption of Bt crops has led to the evolution of Bt resistance. The western corn rootworm, Diabrotica virgifera virgifera, is among the most serious pests of maize in the midwestern United States and is currently managed with Bt maize. To date, there is evidence of field-evolved resistance to all Bt toxins used to manage this pest. While western corn rootworm resistance to Cry3Bb1, and the closely related mCry3A and eCry3.1Ab traits, is widely distributed within the Midwest, fewer cases of Cry34/35Ab1 resistance have been observed, and planting of Cry34/35Ab1 maize is one of the methods used to manage Cry3-resistant rootworm. Results We found that fields with high levels of root injury to Cry34/35Ab1 maize by western corn rootworm were associated with Cry34/35Ab1-resistant western corn rootworm. Additionally, a population not associated with high levels of root injury was found to be resistant to Cry34/35Ab1. In all cases, populations that were resistant to Cry34/35Ab1 also were resistant to Cry3 traits. Conclusions Western corn rootworm resistance to Cry34/35Ab1 has continued to persist in the agricultural landscape and has likely increased. The presence of rootworm populations with resistance to all available Bt traits threatens the utility of current and future transgenic technologies to manage this pest. Decreased reliance on Cry34/35Ab1 and better use of integrated pest management will be essential to preserve Bt susceptibility in western corn rootworm. © 2019 Society of Chemical Industry.

The 2015 Mw 7.8 Gorkha, Nepal Earthquake triggered in excess of 20,000 landslides across 14 districts of Central and Western Nepal. Whilst the instantaneous impact of these landslides was significant, the ongoing effect of the earthquake on changing the potential for rainfall-triggered landsliding in the months and years that followed has remained poorly understood and challenging to predict. To provide insight into how landsliding has evolved since the earthquake, and how it has impacted those living in the affected area, a detailed time-series landslide mapping campaign was undertaken to monitor the evolution of coseismic landslides and the initiation of new post-seismic landslides. This was supplemented by numerical modelling to simulate the future potential reactivation and runout of landslides as debris flows under monsoon rainfall, identifying locations potentially at risk. This analysis shows that landslide hazard was higher in November 2019 as compared to immediately after the 2015 earthquake, with a considerable portion of the landscape being impacted by landsliding. We show that, while pre-existing landslides continued to pose the majority of hazard in the aftermath of the earthquake, a significant number of landslides also occurred in new locations. We discuss the value of this type of analysis in informing the reconstruction and management of settlements at risk by summarizing how this work was integrated into the project Durable Solutions II, that supported communities at risk from landslides. Finally, we consider how such data could be used in future to inform risk sensitive land-use planning and disaster recovery, and to mitigate the impacts of future landsliding in Nepal and beyond.

Coseismic landslides are a major hazard associated with large earthquakes in mountainous regions. Despite growing evidence for their widespread impacts and persistence, current understanding of the evolution of landsliding over time after large earthquakes, the hazard that these landslides pose, and their role in the mountain sediment cascade remains limited. To address this, we present the first systematic multi‐temporal landslide inventory to span the full rupture area of a large continental earthquake across the pre‐, co‐ and post‐seismic periods. We focus on the 3.5 years after the 2015 Mw 7.8 Gorkha earthquake in Nepal and show that throughout this period both the number and area of mapped landslides have remained higher than on the day of the earthquake itself. We document systematic upslope and northward shifts in the density of landsliding through time. Areas where landslides have persisted tend to cluster in space, but those areas that have returned to pre‐earthquake conditions are more dispersed. Whilst both pre‐ and coseismic landslide locations tend to persist within mapped post‐earthquake inventories, a wider population of newly activated but spatially‐dispersed landslides has developed after the earthquake. This is particularly important for post‐earthquake recovery plans that are typically based on hazard assessments conducted immediately after the earthquake and thus do not consider the evolving landslide hazard. We show that recovery back to pre‐earthquake landsliding rates is fundamentally dependent on how that recovery is defined and measured. Clarity around this definition is particularly important for informing a comprehensive approach to post‐earthquake landslide hazard and risk.

Nepal has a rich history of vitamin A research and a national, biannual preschool vitamin A supplementation (VAS) programme that has sustained high coverage for 25 years despite many challenges, including conflict. Key elements of programme success have included (a) evidence of a 26–30% reduction in child mortality from two, in‐country randomized trials; (b) strong political and donor support; (c) positioning local female community health volunteers as key operatives; (d) nationwide community mobilization and demand creation for the programme; and (e) gradual expansion of the programme over a period of several years, conducting and integrating delivery research, and monitoring to allow new approaches to be tested and adapted to available resources. The VAS network has served as a platform for delivering other services, including anthelmintic treatment and screening for acute malnutrition. We estimate that VAS has saved over 45,000 young lives over the past 15 years of attained national coverage. Consumption of vitamin A‐ and carotenoid‐rich foods by children and women nationally remains low, indicating that supplementation is still needed. Current challenges and opportunities to improving vitamin A status include lower VAS coverage among younger children (infants 6–11 months of age), finding ways to increase availability and access to dietary vitamin A sources, and ensuring local programme investments given the recent decentralization of the government.

A study was designed to examine the community composition of canopydwelling arthropods in adjacent fields of cotton, Gossypium hirsutum L., and alfalfa, Medicago sativum L., at Texas A&M University AgriLife Research and Extension Center farm near Lubbock, TX, during the cotton-growing seasons of 2008 and 2009. Samples were collected from 61 row-meter sections of cotton (1.02-m row spacing) and 61 row-meter sections of alfalfa (0.51-m spacing) via a “Keep It Simple Sampler” (KISS). Six samples were collected on each of 11 weekly sampling dates during the cotton-growing seasons of both years. We found that specimens in the canopy-dwelling arthropod community in cotton and alfalfa were from the orders Araneae, Coleoptera, Diptera, Hemiptera, Hymenoptera, Lepidoptera, Neuroptera, and Orthoptera, and in the orders, 41 families were identified. Members of Araneae, Coleoptera, and Hemiptera were most abundant in both crops. Overall, a greater number of arthropod taxa was found in alfalfa, but some arthropod taxa were unique to each crop. Analyses revealed a difference in temporal abundance of captured arthropods at the order (p ≤ 0.018) and family levels (p ≤ 0.021) during cotton squaring, flowering, and boll-development stages, with significantly greater abundance of arthropods at the order level in alfalfa compared to cotton in both years, except during the cotton-flowering period in 2008. Implications of arthropod community differences between alfalfa and cotton were discussed with respect to using alfalfa as a potential source of predators for adjacent cotton.

DOI: https://doi.org/10.3126/nepjoph.v10i2.19185 Introduction: Cataract is a common ailment of the old age hindering daily activities leading to poor quality of life due to poor vision. It is the commonest cause of treatable blindness. In practice, extracapsular cataract excision and small incision cataract surgery are the two-common surgery for cataract these days in developing part like in Nepal. Between these two cataract surgeries, ECCE and SICS; SICS gives the better visual outcome. Methods: This retrospective cohort study was carried out including 286 eyes which were operated either by conventional extracapsular cataract extraction or small-incision cataract surgery. The patient’s demographics, preoperative vision, postoperative parameters/variables were studied from the patient’s record keeping. The postoperative visual outcome and complications were compared in both groups at the immediate post-operative period and at 8 weeks follow up period. Result: Among the total 286 cases, 138 underwent ECCE and 148 underwent SICS. 145 (50.6%) were right eye, 141 (49.3%) were left eye. Among total operated cases, 123 (43%) were mature cataract, 97 (33.9%) immature cataract, 66 (23.1%) hyper-mature cataract. In 172 cases (60.1%) there was a good vision, in 104 cases (36.4%) it was borderline while in rest 10 (3.5%) cases it was poor on the 60th postoperative day. There was the better visual outcome (≥6/18) with SICS (78.3%) than ECCE (40.5%) (p

Western corn rootworm, Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae), has developed resistance to transgenic corn that produces the insecticidal toxin Cry3Bb1 derived from the bacterium Bacillus thuringiensis (Bacillales: Bacillaceae) (Bt), with cross-resistance extending to corn with Bt toxins mCry3A and eCry3.1Ab. Additionally, some populations of western corn rootworm have evolved resistance to Cry34/35Ab1 corn. We conducted a 2-yr field and laboratory study that included three field locations: 1) Bt-susceptible population, 2) field with a recent history of Cry3Bb1 resistance, and 3) field with a long-term history of Cry3Bb1 resistance. The population with recently evolved Cry3Bb1 resistance showed resistance to Cry3Bb1 corn in both laboratory bioassays and field evaluations; by contrast, the population with a long-term history of Cry3Bb1 resistance showed resistance, in both laboratory and field experiments to Cry3Bb1 corn and corn with a pyramid of mCry3A plus eCry3.1Ab corn. Field-based evaluations also showed that the field population with a long-term history of Cry3Bb1 resistance imposed higher root injury to Cry3Bb1 corn and the pyramid of mCry3A plus eCry3.1Ab compared with the susceptible control. The results of this study are discussed in the context of developing strategies to manage western corn rootworm in areas where populations have evolved resistance to Cry3Bb1 corn.

Introduction: Ocular trauma is a major cause of monocular blindness and visual impairment throughout the world. It is estimated that more than 2 million people suffer from ocular trauma annually and 40,000 become visually handicapped permanently. The aim of this study was to evaluate the visual outcome in open globe injury patients. Methods: This study was conducted in Nepal Eye Hospital. All the cases of admitted open globe injuries were examined and managed in the hospital were included in this study. The detail history of trauma and visual acuity was recorded. Clinical diagnosis was made after detail examination of anterior and posterior segment. Patient was treated according to the type of injury. Visual recovery and the cause of poor vision at the time of discharge was also noted. Data was analyzed using the SPSS 11 program. Results: Out of the 100 cases enrolled in the study work related injury was the most frequent injury, metal was the most common causative agent. Males of 20-50 years of age are more vulnerable to open globe injury. Vision improved in 48%, same vision in 39% and deteriorated vision in 13% cases was recorded. Conclusions: Present study reveals that open globe injury can present in varying severity and though the overall prognosis is grave, prompt surgical intervention can result in better visual outcome. The visual outcome in mild to moderate ocular injury was satisfactory but poor in severe injuries. Medical Journal of Shree Birendra Hospital; July-December 2012/vol.11/Issue2/40-43 DOI: http://dx.doi.org/10.3126/mjsbh.v11i2.7909

The evolution of resistance and cross-resistance threaten the sustainability of genetically engineered crops that produce insecticidal toxins derived from the bacterium Bacillus thuringiensis (Bt). Western corn rootworm, Diabrotica virgifera virgifera LeConte, is a serious pest of maize and has been managed with Bt maize since 2003. We conducted laboratory bioassays with maize hybrids producing Bt toxins Cry3Bb1, mCry3A, eCry3.1Ab, and Cry34/35Ab1, which represent all commercialized Bt toxins for management of western corn rootworm. We tested populations from fields where severe injury to Cry3Bb1 maize was observed, and populations that had never been exposed to Bt maize. Consistent with past studies, bioassays indicated that field populations were resistant to Cry3Bb1 maize and mCry3A maize, and that cross-resistance was present between these two types of Bt maize. Additionally, bioassays revealed resistance to eCry3.1Ab maize and cross-resistance among Cry3Bb1, mCry3A and eCry3.1Ab. However, no resistance or cross-resistance was detected for Cry34/35Ab1 maize. This broad-spectrum resistance illustrates the potential for insect pests to develop resistance rapidly to multiple Bt toxins when structural similarities are present among toxins, and raises concerns about the long-term durability of Bt crops for management of some insect pests.

Western corn rootworm, Diabrotica virgifera virgifera LeConte, is a serious pest of corn and is managed with corn that produces insecticidal toxins derived from the bacterium Bacillus thuringiensis (Bt). Beginning in 2009, resistance to Cry3Bb1 corn, and severe injury to Cry3Bb1 corn in the field, was observed in Iowa. However, few data exist on how Cry3Bb1-resistant western corn rootworm interact with various management practices in the field. Using a field experiment, we measured adult emergence and feeding injury to corn roots for both Cry3Bb1-resistant and Cry3Bb1-susceptible populations of western corn rootworm when tested against various Bt corn hybrids and a soil-applied insecticide. Between 2012 and 2013, we evaluated five fields that were associated with greater than one node of feeding injury to Cry3Bb1 corn by western corn rootworm (i.e., problem-field populations), and a laboratory strain that had never been exposed to Bt corn (i.e., control population). Adult emergence for western corn rootworm and root injury to corn were significantly higher in problem-field populations than control populations for both Cry3Bb1 corn and mCry3A corn. By contrast, corn with Cry34/35Ab1, either alone or pyramided with Cry3Bb1, significantly reduced adult emergence and root injury in both problem fields and control fields. In problem fields, application of the soil-applied insecticide to Cry3Bb1 corn significantly reduced root injury, but not adult emergence. Our results are discussed in terms of developing strategies for managing western corn rootworm with resistance to Cry3Bb1 and mCry3A, and delaying the additional evolution of Bt resistance by this pest.

Western corn rootworm, Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae), is a serious pest of corn in the United States, and recent management of western corn rootworm has included planting of Bt corn. Beginning in 2009, western corn rootworm populations with resistance to Cry3Bb1 corn and mCry3A corn were found in Iowa and elsewhere. To date, western corn rootworm populations have remained susceptible to corn producing Bt toxin Cry34/35Ab1. In this study, we used single-plant bioassays to test field populations of western corn rootworm for resistance to Cry34/35Ab1 corn, Cry3Bb1 corn, and mCry3A corn. Bioassays included nine rootworm populations collected from fields where severe injury to Bt corn had been observed and six control populations that had never been exposed to Bt corn. We found incomplete resistance to Cry34/35Ab1 corn among field populations collected from fields where severe injury to corn producing Cry34/35Ab1, either singly or as a pyramid, had been observed. Additionally, resistance to Cry3Bb1 corn and mCry3A corn was found among the majority of populations tested. These first cases of resistance to Cry34/35Ab1 corn, and the presence of resistance to multiple Bt toxins by western corn rootworm, highlight the potential vulnerability of Bt corn to the evolution of resistance by western corn rootworm. The use of more diversified management practices, in addition to insect resistance management, likely will be essential to sustain the viability of Bt corn for management of western corn rootworm.

Three planting-date windows [early — 3 weeks before (i.e., 26–29 April) the recommended optimum planting window; timely — the commonly recommended optimum planting window of 16–19 May; and late — 3 weeks after (i.e., 6–9 June) the recommended optimum planting window] and three planting patterns (Solid — solidrow stand; Skip 2×1 — two rows planted, one row skipped; and Skip 2×2 — two rows planted, two rows skipped) were evaluated to determine their influence on abundance and population dynamics of arthropods during 3 years in cotton, Gossypium hirsutum L., on the Texas Rolling Plains. Arthropod species sampled included thrips, Frankliniella occidentalis (Pergande); cotton fleahopper, Pseudatomoscelis seriatus (Reuter); cotton aphid, Aphis gossypii Glover; and bollworm, Helicoverpa zea (Boddie). Planting date significantly influenced aphid abundance. Fewer aphids were found in early-planted cotton (1.0 per leaf) compared with timely (2.3 per leaf) or late (1.8 per leaf) planted cotton. Similarly, ...

1 A 2-year field study was conducted to generate data on seasonal abundance patterns of cotton aphids Aphis gossypii Glover and to develop a mechanistic model based on cumulative population size. The treatments consisted of three irrigation levels (Low, Medium and High) with 65%, 75% and 85% evapotranspiration replacement and three nitrogen fertility treatments (blanket-rate-N, variable-rate-N and no nitrogen). 2 A nonlinear regression equation, the analytical solution of a cumulative size mechanistic model, was fitted to each of the 27 individual data sets collected in 2003 and in 2004. The size and time of the peak, the cumulative aphid density, and the birth and death rates were estimated for each population, and each of these five variables was analyzed as a response variable in the analysis of variance. 3 For 2003 (a dry year), the Water (irrigation) main effect was found to be significant for the time of peak, the death rate and the cumulative density. The lower aphid death rate at low water levels might be due to the water stress in plants. 4 For 2004 (a year with moderate precipitation), the Nitrogen main effect was significant for both the birth and death rates. As nitrogen applications were increased, the decrease in both the aphid birth and death rates translates into a decrease in crowding and an increase in aphid survival. 5 The fact that treatment effects may be manifested through birth and death rate parameters in the new mechanistic model opens up new avenues for analyzing population size data of this kind.

Thrips (Thysanoptera: Thripidae( and cotton fleahoppers, Pseudatomoscelis seriatus (Reuter( (Hemiptera: Miridae(, are considered to be significant economic pests of cotton in Texas, USA. A 2-year field study evaluated the influence of planting date, tillage practice, and Bt cotton on seasonal abundance patterns of thrips and cotton fleahoppers and their within-plant distribution patterns in cotton. Thrips were sampled visually while fleahoppers were sampled both visually and with a ‘beat bucket’ at weekly intervals throughout the growing season. Thrips infestations had two distinct peaks, with the first peak at the one to two main stem node leaf stage and the second peak during the flowering stage. Cotton fleahoppers had only one infestation peak at 13 – 15 weeks after planting (after crop cutout(. Average seasonal abundance of each pest was significantly influenced by tillage practice with higher numbers in conventional tillage compared with that in conservation tillage plots. Thrips abundance w...

A 2-yr field study was conducted to examine the effectiveness of two sampling methods (visual and plant washing techniques) for western flower thrips, Frankliniella occidentalis (Pergande), and five sampling methods (visual, beat bucket, drop cloth, sweep net, and vacuum) for cotton fleahopper, Pseudatomoscelis seriatus (Reuter), in Texas cotton, Gossypium hirsutum (L.), and to develop sequential sampling plans for each pest. The plant washing technique gave similar results to the visual method in detecting adult thrips, but the washing technique detected significantly higher number of thrips larvae compared with the visual sampling. Visual sampling detected the highest number of fleahoppers followed by beat bucket, drop cloth, vacuum, and sweep net sampling, with no significant difference in catch efficiency between vacuum and sweep net methods. However, based on fixed precision cost reliability, the sweep net sampling was the most cost-effective method followed by vacuum, beat bucket, drop cloth, and visual sampling. Taylor's Power Law analysis revealed that the field dispersion patterns of both thrips and fleahoppers were aggregated throughout the crop growing season. For thrips management decision based on visual sampling (0.25 precision), 15 plants were estimated to be the minimum sample size when the estimated population density was one thrips per plant, whereas the minimum sample size was nine plants when thrips density approached 10 thrips per plant. The minimum visual sample size for cotton fleahoppers was 16 plants when the density was one fleahopper per plant, but the sample size decreased rapidly with an increase in fleahopper density, requiring only four plants to be sampled when the density was 10 fleahoppers per plant. Sequential sampling plans were developed and validated with independent data for both thrips and cotton fleahoppers.

A functional response study of the eight most common arthropod predators of cotton bollworm, Helicoverpa zea (Boddie), eggs was conducted in the laboratory. Predators were starved for 24 h, and single predators were exposed to different prey density treatments. Predation response was observed at 6, 12, and 24 h after feeding trials began. At the highest prey density (150 eggs per predator), Hippodamia convergens Guerin-Meneville and Collops quadrimaculatus (F.) adults and Chrysopa oculata Say larvae showed the highest consumption rates (116, 85, and 119 eggs/24 h, respectively), followed by H. convergens larvae (51 eggs/24 h), adult Geocoris punctipes (Say) (45 eggs/24 h), and adult Scymnus loewii Mulsant, Orius insidiosus (Say), Notoxus spp., and Nabis capsiformis Germar (1, 1, 10, and 12 eggs/24 h, respectively). Adult Notoxus spp., N. capsiformis, and O. insidiosus showed type 1 functional response, whereas adult C. quadrimaculatus, G. punctipes, H. convergens, and larval H. convergens and C. oculata showed type 2 response. All predators consumed the highest number of bollworm eggs at 35C and the lowest numbers at 15C; predation rate at 35C was four times higher than that at 15C. The prey densityÐ dependent behavior of predators and effect of temperature on their predation behavior are discussed.

Introduction: Intraocular pressure (IOP) increases when changing from sitting to supine position with an average difference of 0.3 to 6.0mm of Hg. These postural changes of IOP have been found in normal persons, patients with ocular hypertension and normal tension glaucoma. The eye is relatively non-distensible, even small changes in the volume of aqueous humor may significantly change IOP. The increase in resistance in aqueous flow is thought to be the reason for higher IOP in supine compared to sitting position. The aim of this study was to analyze the effects of posture in intraocular pressure in normal and primary open angle glaucoma subjects. Methods: It was a prospective cross sectional study done in Armed Forces Medical College, Pune, between May, 2007 to May, 2009 with sample sized of 60 people (30 controls and 30 Primary open angle glaucoma). Patients underwent complete ocular examination. Two drops of Topical 4% lignocaine were instilled. IOP measurements were taken by Rebound tonometer in sitting and supine positions at 10 min and 30 min interval respectively. Results: Control group (40-76 yrs) and POAG group (40-78 yrs) were found to have a mean rise of IOP of 1.65 and 2 mm of Hg respectively from sitting to lying for 10min, and a mean rise of 2.52 and 5.36 mm of Hg respectively from sitting to lying for 30min. Conclusions: The rise in IOP due to change of posture from sitting to supine positions was significantly higher in glaucomatous patients. Medical Journal of Shree Birendra Hospital; July-December 2012/vol.11/Issue2/21-23 DOI: http://dx.doi.org/10.3126/mjsbh.v11i2.7904

Introduction: Although oculomotor nerve palsy is associated with signifycant morbidity. The etiology of oculomotor nerve palsy are ischemic, trauma, aneurysm, tumors, inflammatory, idiopathic etc. The present study was performed to determine the etiology of isolated oculomotor nerve palsy in our population. Methods: The hospital data of patients of isolated oculomotor nerve palsy cases reported to the eye department of Shree Birendra Hospital from March 2009 to March 2011 were collected and retrospectively analyzed for the etiology of the disease. The detail history (ocular and medical), examination and investigations were collected from patient’s case records. All patients had been evaluated for hypertension and diabetes mellitus. Neuroimaging, MRI had been performed in all cases. The etiology of isolated oculomotor nerve palsy was classified into ischemia, idiopathic, trauma, aneurysm and neoplastic. Results: During the study period there were 16 eyes of 16 patients who were suffering from isolated oculomotor nerve palsy. The commonest cause was found to be ischemic in 7 patients (43.75%) followed by idiopathic in 5 patients (31.25%). Pupil was involved in 3 patients (18.75%). MRI was carried out in all 16 patients, but revealed positive only in two cases (one intracranial aneurysm and other Non Hodgkin’s Lymphoma). Remaining 14 MRI were normal. Conclusions: Oculomotor nerve palsy is an uncommon disease and commonest cause was ischemic followed by idiopathic. The cause should be ruled out as the treatment depends on the cause. Medical Journal of Shree Birendra Hospital; Jan-June 2012/vol.11/Issue1/21-23 DOI: http://dx.doi.org/10.3126/mjsbh.v11i1.7762

A 2-year study was conducted to characterize the intercrop movement of convergent lady beetle, Hippodamia convergens Guerin-Meneville (Coleoptera: Coccinellidae) between adjacent cotton and alfalfa. A dual protein-marking method was used to assess the intercrop movement of the lady beetles in each crop. In turns field collected lady beetles in each crop were assayed by protein specific ELISA to quantify the movement of beetles between the crops. Results indicated that a high percentage of convergent lady beetles caught in cotton (46% in 2008; 56% in 2009) and alfalfa (46% in 2008; 71% in 2009) contained a protein mark, thus indicating that convergent lady beetle movement was largely bidirectional between the adjacent crops. Although at a much lower proportion, lady beetles also showed unidirectional movement from cotton to alfalfa (5% in 2008 and 6% in 2009) and from alfalfa to cotton (9% in 2008 and 14% in 2009). The season-long bidirectional movement exhibited by the beetles was significantly higher in alfalfa than cotton during both years of the study. The total influx of lady beetles (bidirectional and unidirectional combined) was significantly higher in alfalfa compared with that in cotton for both years. While convergent lady beetles moved between adjacent cotton and alfalfa, they were more attracted to alfalfa when cotton was not flowering and/or when alfalfa offered more opportunities for prey. This study offers much needed information on intercrop movement of the convergent lady beetle that should facilitate integrated pest management decisions in cotton utilizing conservation biological control.

A microsatellite-enriched partial genomic DNA library of Lygus hesperus was generated and screened by sequencing. Ten polymorphic microsatellite marker loci were characterized by genotyping 92 insect samples. The observed number of alleles ranged from three to seven with an average of 4.5 (SE ± 0.45), while the effective number of alleles ranged from 1.21 to 3.02 with an average of 2.14 (SE ± 0.20). Significant deviations from Hardy–Weinberg expectations were detected at three loci. Significant linkage disequilibrium was also detected between the loci LhMS2-54 and LhMS3-32. Seven of the L. hesperus markers could be transferred to Lygus lineolaris.

Population abundance and species composition of rice green leafhoppers was monitored by sweepnetsampling or lighttrapping from more than 116 rice growing locations in different altitudinal regions of Nepal from 1992 to 1994. Three species of leafhopper Nephotettix virescens, N. nigropictus and Recilia dorsalis, were found in most samples, and a few leafhoppers similar to N. malayanus were occasionally observed. N. virescens was predominant (80%) in samples from low altitude rice fields ( 1000 m) was negligible or absent. N. nigropictus, in contrast, was more widely distributed in rice fields at both low and high altitude, and predominated (95%) in high altitude rice fields ( >1000 m). The light trap data from rice fields at low altitude (250 m) showed that both N. virescens and N. nigropictus were caught throughout the year, with few or none caught during winter (December- February). The abundance of these two insects increased from Apri...

Summary. A survey of rice fields during the main growing seasons in 81 locations from 21 districts of the Southern Terai region of Nepal indicated that rice tungro was primarily restricted to the Hardinath (Janakpur) and Parwanipur (Bara) regions. The tungro incidence in Hardinath ranged from 17% to 51% and in Parwanipur from 6% to 61% causing about 89% grain yield loss in Hardinath. Both rice tungro bacilliform badnavirus (RTBV) and rice tungro spherical picornavirus (RTSV) were found in tungro isolates collected from Hardinath and Parwanipur. These isolates were transmitted by Nephotettix virescens and leaf extracts reacted to antisera against RTBV and RTSV. In a dot blot hybridisation assay, leaf extracts of 12 weed species collected from the tungro-affected area in Hardinath and Parwanipur also reacted with RTBV DNA probes. On mass inoculation of 15 popular rice cultivars most became more than 50% infected and only cv. Radha 9 had low (22.2%) infection. RTBV DNA and the coat protein region of RTSV from the Hardinath isolate were cloned and partially characterised. A comparative analyses by restriction endonuclease digestion, cross hybridisation, the polymerase chain reaction and partial sequencing indicated that the Nepalese RTBV DNA clone and the cDNA clones of the RTSV RNA were more similar to the various tungro isolates from the Indian subcontinent than to those from the Philippines.

The cotton aphid, Aphis gossypii Glover, predation rate of convergent lady beetle, Hippodamia convergens Guerin-Meneville, was determined by assigning a single predator randomly to each of four prey density treatments in the laboratory. Prey densities included 25, 50, 100, and 200 aphids per Petri dish arena. Predation response was recorded at 1, 4, 8, 16, 24, and 48 h after assigning predators to their prey treatments. Rate of consumption increased through time, with all 25 aphids consumed during the first 4 h of the experiment. At the highest density, adult lady beetle consumed on average 49, 99, 131, 163, 183, and 200 aphids within 1, 4, 8, 16, 24 and 48 h, respectively. Predators showed a curvilinear feeding response in relation to total available time, indicating that convergent lady beetles have the potential to suppress larger populations of aphids through continuous feeding by regulating their predation efficiency during feeding. The analysis of age-specific mortality in absence of prey revealed that lady beetles could survive for an extended period of time (more than 2 weeks) without prey. The ability of a predator to survive without prey delays or prevents the rebound of pest populations that is a significant factor in natural biological control. A two-year field sampling of 10 cotton arthropod predator species showed that spiders (27%) were the most dominant foliage dwelling predators in the Texas High Plains cotton followed by convergent lady beetles (23.5%), hooded beetles (13.5%), minute pirate bugs (11%), green lacewings (9.5%), bigeyed bugs (7.5%), scymnus beetles (3%), soft-winged flower beetles (2%), damsel bugs (1.5%), and assassin bugs (1.5%). A field cage study showed that one H. convergens adult per plant released at prey density of one aphid per leaf kept the aphid population below economic threshold for the entire growing season.

A 2-year field study was conducted in the southern High Plains region of Texas to evaluate the effect of tillage system and cotton planting date window on seasonal abundance and activity patterns of predacious ground beetles. The experiment was deployed in a split-plot randomized block design with tillage as the main-plot factor and planting date as the subplot factor. There were two levels for each factor. The two tillage systems were conservation tillage (30% or more of the soil surface is covered with crop residue) and conventional tillage. The two cotton planting date window treatments were early May (normal planting) and early June (late planting). Five prevailing predacious ground beetles, Cicindela sexguttata F., Calosoma scrutator Drees, Pasimachus spp., Pterostichus spp., and Megacephala Carolina L. (Coleoptera: Carabidae), were monitored using pitfall traps at 2-week intervals from June 2002 to October 2003. The highest total number of ground beetles (6/trap) was observed on 9 July 2003. Cicindela sexguttata was the dominant ground dwelling predacious beetle among the five species. A significant difference between the two tillage systems was observed in the abundances of Pterostichus spp. and C. sexguttata. In 2002. significantly more Pterostichus spp. were recorded from conventional plots (0.27/trap) than were recorded from conservation tillage plots (0.05/trap). Significantly more C. sexguttata were recorded in 2003 from conservation plots (3.77/trap) than were recorded from conventional tillage plots (1.04/trap). There was a significant interaction between year and tillage treatments. However, there was no significant difference in the abundances of M. Carolina and Pasimachus spp. between the two tillage practices in either of the two years. M. Carolina numbers were significantly higher in late-planted cotton compared with those observed in normal-planted cotton. However, planting date window had no significant influence on the activity patterns of the other species. Ground beetle species abundance, diversity, and species richness were significantly higher in conservation tillage plots. This suggests that field conditions arising from the practice of conservation tillage may support higher predacious ground beetle activity than might be observed under field conditions arising from conventional tillage practices.

Introduction: Blindness is one of the most tragic yet often avoidable disabilities in the developing world. The pattern of ocular diseases varies in different parts of Nepal due to differences in socioeconomic and geographic factors. This retrospective study likely reflects the pattern of ocular diseases in Kathmandu Valley. Aim: To assess the patterns of ocular disease in the patients attending the outpatient department of Ophthalmology from 14th April 2009 to 13th April 2010 at the Army Hospital. Methods: This is a retrospective study and all the new cases which attended the department of Ophthalmology of Shree Birendra Hospital in the year 2066 were included. The diseases were divided into 11 groups i.e. lid & adenexal disorder, disease of conjunctiva & sclera, corneal diseases, lens associated disorders, diseases of uveal tract, refractive error, glaucoma & its associations, posterior segment diseases, ocular & systemic neoplastic disorders, Nekebadi (annual medical check up) and others. Result: The total number of patients recorded in the department of Ophthalmology is 16709. Among them 4473 were regular serving army personnel and 12236 were ex-army and army families. Conclusion: The pattern of eye disease varies in different age groups. In younger age group conjunctival, scleral disease and refractive error were commonly seen whereas in elder age group lens disorder was frequently seen. The number of blind patients was more in females than in male patients. Key words: Conjunctivitis; Cataract; Blindness. DOI: http://dx.doi.org/10.3126/mjsbh.v9i2.5023 Medical Journal of Shree Birendra Hospital Vol.9(2) 2010: 30-37