Prospects and Present Status and of Entomopathogenic Nematodes (Steinernematidae and Heterorhabditidae) in Nepal

Naturally occurring entomopathogenic nematodes(EPN) and their symbiotic bacteria are important biotic factor in suppression of insect pest populations in soil and cryptic habitats. These nematodes can control pests due to their mutualistic association with bacteria that kill the hosts by septicemia and make the environment favorable for EPN development and reproduction.The virulent species of EPN can commercially be mass produced as biological control agents all over the world. Nepal  has a great potential to exploit these beneficial nematodes for the control of insect pests. Exploration of indigenous EPN is receiving attention around th eworld. Numerous surveys conducted worldwide have detected many indigenous isolates. Altogether 115 species of EPN (97 of Steinernema and 18 of Heterorhabdits species) have been reported so far worldwide. However, very limited research on EPN in Nepal has been done with 29 species only with some new species. Hence,the isolation and description of the native efficacious species and populationsof EPN is the need of the hour,not only from a biodiversity view point but also from an environmental and biological control perspective.Thei dentification of EPNs, adapted to environmental and climatic conditions of cultivated areas, is important for sustainable pest suppression in integrated management programs in agricultural areas of Nepal. This article provides an overview of recent development on EPN research and evaluates their potential for use and exploitation in Nepal

Genetic diversity in invasive populations of Argentine stem weevil associated with adaptation to biocontrol

Modified, agricultural landscapes are susceptible to damage by insect pests. Biological control of pests is typically successful once a control agent has established, but this depends on the agent’s capacity to co-evolve with the host. Theoretical studies have shown that different levels of genetic variation between the host and the control agent will lead to rapid evolution of resistance in the host. Although this has been reported in one instance, the underlying genetics have not been studied. To address this, we measured the genetic variation in New Zealand populations of the pasture pest, Argentine stem weevil (Listronotus bonariensis), which is controlled with declining effectiveness by a parasitoid wasp, Microctonus hyperodae. We constructed a draft reference genome of the weevil, collected samples from a geographical survey of 10 sites around New Zealand, and genotyped them using a modified genotyping-by-sequencing approach. New Zealand populations of Argentine stem weevil have high levels of heterozygosity and low population structure, consistent with a large effective population size and frequent gene flow. This implies that Argentine stem weevils were able to evolve more rapidly than their biocontrol agent, which reproduces asexually. These findings show that monitoring genetic diversity in biocontrol agents and their targets is critical for long-term success of biological control

Mycorrhizal fungi as mediators of defence against insect pests in agricultural systems

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/74655/1/j.1461-9563.2009.00445.x.pd

Beneficial insects

The Oklahoma Cooperative Extension Service periodically issues revisions to its publications. The most current edition is made available. For access to an earlier edition, if available for this title, please contact the Oklahoma State University Library Archives by email at [email protected] or by phone at 405-744-6311

Horticulture tips, April 2006

Horticulture and Landscape Architectur

Beneficial insects

The Oklahoma Cooperative Extension Service periodically issues revisions to its publications. The most current edition is made available. For access to an earlier edition, if available for this title, please contact the Oklahoma State University Library Archives by email at [email protected] or by phone at 405-744-6311

Compatibility of Heterorhabditis amazonensis MC01 (Nematoda: rhabditida) with fertilizers and soil conditioners

Entomopathogenic nematodes are natural enemies of insect pests present in the soil; however, the intensive use of agricultural inputs can affect the action of these organisms. The objective of this study was to evaluate the effects of exposure of the nematode Heterorhabditis amazonensis MC01 to soil fertilizers containing different active ingredient, verifying their influence in the viability, infectivity and nematode production in Tenebrio molitor L. larvae. Nine products were tested, including fertilizers and soil conditioners, using the adapted IOBC/WPRS protocol. The infective juveniles were exposed to the highest concentration recommended by the manufacturer of each product for a period of 48 h. After this period, the viability, infectivity and production were evaluated and the values of mortality, infectivity reduction, production reduction and insecticide effect were obtained in order to classify the products according to IOBC criteria. In this way, the nematode H. amazonensis MC01 was compatible with most of the products under the tested conditions, so could be present in the soil at the same time. However, the product Nutriterge® Formula 3 was considered slightly harmful and Nem out® considered harmful. However, further field tests should be performed with these products to prove the deleterious effect on the nematode tested

Rhodes Newsletter

The Old Rhodian Union Newsletter keeping in contact with Alumni and informing them of the latest news from Rhodes University. The publication ran from 1951 to 2001, and was subsequenlty replaced with an electronic newsletter distributed via electronic mail