Nar Ranabhat

Wheat breeders are developing new virus-resistant varieties; however, it is assumed that only a few viruses or well-known viruses are present in the field. New sequencing technology is allowing for better determination of natural field virus populations. For three years, 2019-2021, Kansas wheat field surveys were conducted to determine the constituents of natural field virus populations using nanopore sequencing. During analysis, brome mosaic virus (BMV) was identified for the first time in Kansas but was in association with other wheat viruses. Brome mosaic virus was identified from 29 out of 47 different Kansas counties sampled and 44% of the total samples. BMV was found co-infected with wheat streak mosaic virus (WSMV) and Triticum mosaic virus (TriMV) in 27.8% of the samples, with WSMV only (13.9%) and co-infected with WSMV + TriMV + High Plains wheat mosaic emaravirus (HPWMoV) (13.9%). RNA genomes of Kansas BMV isolates had 99.4 to 100% nucleotide and amino acid sequence identi...

In 2018, over 277,000 bushels of wheat were produced on 7.7 million acres of land in Kansas alone. Based on the price of wheat by the end of 2018, this accounted for $1.44 million. This wheat is normally rotated with soybeans or fallow, but recent interest has arisen regarding the growth of peas in northern Kansas. As of 2019, there are both research and commercial growing operations underway. Many plant diseases have been especially prevalent during the summer because of the high rainfall and heat. In order to assess the severity of pea disease in Kansas, as well as explore potential interconnectivity between wheat and pea pathogens, a survey was conducted, and efforts were made to isolate and culture fungal pathogens of both wheat and pea

Wheat streak mosaic virus (WSMV) is a common wheat virus causing economic losses to production in the Great Plains of North America. Reproducible inoculation of WSMV by mechanical methods is essential to evaluate the resistance in breeding lines and relies on successful inoculation and infectivity of the virus particles. We used reverse transcription-quantitative PCR (RT-qPCR) for absolute quantification of viral genome copy numbers in both WSMV inoculum and in infected wheat leaves. A time-course study was designed to determine the viability of WSMV in inoculum over time as well as the copy number related to the phenotypic rating scale. In the phosphate inoculation buffer, WSMV was stable with average viral genome copy number 1.86 × 106 ± 4.85 × 105. Plants inoculated with this inoculation buffer using finger rub mechanical inoculation contained WSMV genome copy numbers in the infected leaves ranging between 2.66 × 104 and 4.69 × 106 at 21 to 28 days post-inoculation. Viral copy nu...

Beekeeping is one of the promising ventures for economically poor families in Nepal. Knowledge about the bee flora of a certain area is very crucial for the farmers. A study was conducted in mid hills of Central Nepal during 2003-04 and 2008-09 to monitor the common plant species visited by bees with their visiting time and seasons. The flowering period of those plant species were also observed. Observations were made on the bees’ activities on flowers of different plant species. Relevant information was also collected through informal key informant interviews. The plant species visited by the bees and the bee species (mainly Apis cerena with some Apis melifera) themselves were collected, preserved and identified. Plants were categorized as major, medium and minor sources of pollen and/or nectar. The pollen and nectar statuses in different plants were also determined. A total of 158 plant species were identified as main bee flora in the study area. Among them, 19 species were hortic...

Integrated pest management is at the foundation of sustainable cropping systems. This thesis investigated 1) the influence of alternative host plants and agronomic practices on Wheat streak mosaic virus (WSMV) risk, and 2) how cover crop termination methods influence diseases in grazed organic, tilled organic, and chemical no-till systems. To assess the influence of alternative hosts including volunteer wheat, Bromus tectorum, Setaria viridis, and Zea mays on WSMV incidence and its vector, the wheat curl mite (Aceria tosichella, WCM) movement during the fall, a ‘trap plant’ capture system was used. In 2013, alternative hosts had similar WCM infestation levels compared to the control in most weeks. In 2014, spring planted B. tectorum and volunteer wheat increased the incidence of WSMV and abundance of WCM compared to control. In a study assessing the impact of planting date and winter wheat variety on WSMV incidence, there was almost no infection of WSMV across resistant wheat variet...

A study was conducted at the southern belt of Kaski District during August 2003 to July 2004 to identify natural enemies of honey bee Apis cerana Fab. and associated problems in beekeeping. Four species of wasps viz: Vespa velutina, V. bicolor, V. tropica and V. basalis were observed preying on Apis cerana. Six species of Ants were collected from hive attacking honey bees viz Componatus sp, Sima sp, Monomorium sp, Myrmica sp and two unidentified. Four species of spider viz Palatar indicus, Ariope areuta and the other two belonging to family Theridae and Araneidae were collected from the hives. Two species of Birds, Green bee- Eater and Drongo; One species of Beetle, One Chalcid (Antrocephalus sp) were identified.The disease Thaisac brood, Mite, Wax Moth and pesticide damage, deforestation, absconding of bees, lack of technical knowledge were important problems for apiculture in study area.  Key words: Apis cerana F; Enemies;  Pesticide;  Absconding;  Kaski  Journal of Natural Histor...

Subodh Adhikari, Department of Environmental Sciences, Amrit Campus, Tribhuvan University, Nepal, Kathmandu, Nepal, Nar B. Ranabhat, Department of Zoology, Tribhuvan University, Kathmandu, Nepal and Babu R. Paudel, Botany, Tribhuvan University, ...

Pollen is offered as alternative or supplementary food for predacious mites; however, it may vary in its nutritional value. Body weight appears a representative parameter to describe food quality. Thus, we assessed the body weight for adults of the generalist mites Amblyseius swirskii, Amblydromalus limonicus, and Neoseiulus cucumeris reared on 22, 12, and 6 pollen species, respectively. In addition, A. swirskii and A. limonicus was reared on codling moth eggs. In all mite species, female body weight was higher than that of males, ranging between 4.33 and 8.18 µg for A. swirskii, 2.56-6.53 µg for A. limonicus, and 4.66-5.92 µg for N. cucumeris. Male body weight ranged between 1.78 and 3.28 µg, 1.37-3.06 µg, and 2.73-3.03 µg, respectively. Nutritional quality of pollen was neither consistent among the mite species nor among sex, revealing superior quality of Quercus macranthera pollen for females of A. swirskii and Tulipa gesneriana pollen for males, Alnus incana pollen for females of A. limonicus and Aesculus hippocastanum pollen for males, and Ae. hippocastanum pollen for both sexes of N. cucumeris. The results are discussed against the background of known or putative pollen chemistry and mite's nutritional physiology.