Can rational sampling maximise isolation and fix distribution measure of entomopathogenic nematodes?

Summary Entomopathogenic nematodes (EPN) can infect and kill a wide range of insect pests and are used as safe alternatives to chemical insecticides. Hence, a hypothesis was tested for obtaining EPN with high recovery frequency value and accurate distribution pattern based on combining four factors: favourable sampling method, time and site targeting and use of multiple extraction technique. As the extreme diversity of EPN sampling makes any generalisation from a given case study difficult, this functional sampling was limited to recovering EPN from citrus trees only in Egypt. It could both detect more EPN isolates and allow the application of different indices of dispersion to study their spatial distribution pattern. Therefore, stratified random and systematic sampling from weed-infested soil under tree canopy during the season of abundant insect pests was done, followed by multiple cycles of Galleria-baiting technique. Consequently, the nematodes were recovered from the seven surveyed groves (100%) and from 37 of 60 (61.7%) soil samples. The spatial distribution of these EPN isolates, previously identified as Heterorhabditis indica, was characterised using five dispersion indices, which were mainly a random rather than an over-dispersed distribution.

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Spatial distribution pattern of Tarsius Lariang in lore lindu national park

Indonesian Journal of Electrical Engineering and Computer Science ◽

10.11591/ijeecs.v13.i2.pp606-614 ◽

2019 ◽

Vol 13 (2) ◽

pp. 606 ◽

Cited By ~ 1

Author(s):

Abdul Rosyid ◽

Yanto Santosa ◽

I Nengah Surati Jaya ◽

M. Bismark ◽

Agus P. Kartono

Keyword(s):

Spatial Distribution ◽

Distribution Pattern ◽

Land Surface ◽

National Park ◽

Spatial Distribution Pattern ◽

Systematic Sampling ◽

Affecting Factors ◽

Factors Affecting ◽

Insect Abundance ◽

Lore Lindu National Park

Tarsius lariang (T. lariang) is an endemic species in Lore Lindu National Park (LLNP). Available information regarding T. lariang is limited to only morphological, anatomical, cytogenetic, and voices issues. Knowledge for its geospatial characteristics such as spatial preferences and spatial distribution is rare. The main objective of this study is to identify the spatial distribution pattern of T. lariang in LLNP. An additional objective is to identify the environmental factors affecting its spatial distribution patterns. Field observation for distribution pattern was done at the observation plot that were using systematic sampling with random start. Furthermore, the density estimation in each point was calculated using Triangle Count and Concentration Count method, while insect abundance was estimated using light traps sample data. Finally, spatial pattern was estimated using nearest neighbor index, while the environmental affecting factors were identified by using spatial analysis and correlation analyses. From 45 observation points, the T. lariang distribution pattern was clumped. It is also recognized that the significant factors affecting the spatial distribution were insect abundance, proximity from the commercially utilized land, and land surface temperature.

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Variation in the Susceptibility of Drosophila to Different Entomopathogenic Nematodes

Infection and Immunity ◽

10.1128/iai.02740-14 ◽

2015 ◽

Vol 83 (3) ◽

pp. 1130-1138 ◽

Cited By ~ 38

Author(s):

Jennifer M. Peña ◽

Mayra A. Carrillo ◽

Elissa A. Hallem

Keyword(s):

Immune Response ◽

Entomopathogenic Nematodes ◽

Parasitic Nematode ◽

Insect Pests ◽

Model System ◽

Nematode Infection ◽

Xenorhabdus Nematophila ◽

Content Type ◽

Wide Range ◽

Insect Immune Response

Entomopathogenic nematodes (EPNs) in the generaHeterorhabditisandSteinernemaare lethal parasites of insects that are of interest as models for understanding parasite-host interactions and as biocontrol agents for insect pests. EPNs harbor a bacterial endosymbiont in their gut that assists in insect killing. EPNs are capable of infecting and killing a wide range of insects, yet how the nematodes and their bacterial endosymbionts interact with the insect immune system is poorly understood. Here, we develop a versatile model system for understanding the insect immune response to parasitic nematode infection that consists of seven species of EPNs as model parasites and five species ofDrosophilafruit flies as model hosts. We show that the EPNSteinernema carpocapsae, which is widely used for insect control, is capable of infecting and killingD. melanogasterlarvae.S. carpocapsaeis associated with the bacteriumXenorhabdus nematophila, and we show thatX. nematophilainduces expression of a subset of antimicrobial peptide genes and suppresses the melanization response to the nematode. We further show that EPNs vary in their virulence towardD. melanogasterand thatDrosophilaspecies vary in their susceptibilities to EPN infection. Differences in virulence among different EPN-host combinations result from differences in both rates of infection and rates of postinfection survival. Our results establish a powerful model system for understanding mechanisms of host-parasite interactions and the insect immune response to parasitic nematode infection.

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