scholarly journals Effect of soil temperature and moisture on the pathogenicity of two species of entomopathogenic nematodes (Rhabditida: Steinernematidae)

2010 ◽  
Vol 27 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Štěpánka Radová ◽  
Zuzana Trnková
Keyword(s):  
Soil Moisture ◽  
Soil Temperature ◽  
Entomopathogenic Nematodes ◽  
Nematode Species ◽  
Tenebrio Molitor ◽  
Steinernema Carpocapsae ◽  
Dry Conditions ◽  
Insect Mortality ◽  
The Impact ◽  
Soil Temperature And Moisture

Effect of soil temperature and moisture on the pathogenicity of two species of entomopathogenic nematodes (Rhabditida: Steinernematidae)This study investigated the impact of soil temperature and soil moisture on the virulence of the entomopathogenic nematodes Steinernema carpocapsae and S. feltiae. The effects of temperatures of 10, 15 and 25 °C and humidity of 6% and 12.5% were tested against the larvae of Tenebrio molitor. The nematodes were tested in two concentrations of 50 nematodes and 500 nematodes per box. S. carpocapsae was generally significantly more efficient at the highest temperature (25 °C) than S. feltiae, especially at the lower concentration of 50 nematodes per box. S. feltiae recorded higher insect mortality at lower temperatures (15 °C and 10 °C). The virulence of both tested nematode species was low (0-26%) at 10 °C after 7 days, but in the case of S. feltiae increased to 66% after 14 days. The efficacy when tested with 6% moisture at 15 °C was low (4% for both nematode species) compared with 12.5% moisture, where after seven days it reached 54% for S. carpocapsae and 70% for S. feltiae, although generally, S. feltiae was more efficient under dry conditions than S. carpocapsae. Insect mortality inreased significantly after remoistening of the soil, especially with S. feltiae (500 nematodes per box) where mortality reached 46% two weeks after remoistening.

Influence of pesticides, soil temperature and moisture on entomopathogenic nematodes from southern Benin and control of underground termite nest populations

Nematology ◽  
2015 ◽  
Vol 17 (9) ◽  
pp. 1057-1069 ◽  
Author(s):  
Hugues Baimey ◽  
Lionel Zadji ◽  
Leonard Afouda ◽  
Maurice Moens ◽  
Wilfrida Decraemer
Keyword(s):  
Soil Moisture ◽  
Soil Temperature ◽  
Entomopathogenic Nematodes ◽  
Galleria Mellonella ◽  
Macrotermes Bellicosus ◽  
And Control ◽  
The Impact ◽  
Termite Nest ◽  
Southern Benin ◽  
Soil Temperature And Moisture

The influence of three pesticides on the viability and infectivity of four Beninese isolates of entomopathogenic nematodes (EPN), Heterorhabditis indica Ayogbe1, H. sonorensis Azohoue2, H. sonorensis Ze3, and Steinernema sp. Bembereke, was determined. The impact of both soil temperature and soil moisture on the virulence of these EPN to Trinervitermes occidentalis was investigated in laboratory assays. The effect of EPN-infected Galleria mellonella larvae on underground populations of Macrotermes bellicosus was also examined. All tested Heterorhabditis species were more tolerant to glyphosate and fipronil than the Steinernema species. Heterorhabditis sonorensis Azohoue2, showed the best results with 63.2% termite mortality at a soil temperature of 35°C. The increase of soil moisture to 20% (w/w) did not negatively influence the virulence of tested EPN. The underground populations of 71% or 60% treated nests were controlled by H. sonorensis Azohoue2- or H. indica Ayogbe1-infected G. mellonella larvae, respectively.

scholarly journals Earthworms are little affected by reduced soil tillage methods in vineyards

2017 ◽  
Vol 63 (No. 6) ◽  
pp. 257-263 ◽  
Author(s):  
Faber Florian ◽  
Wachter Elisabeth ◽  
Zaller Johann G
Keyword(s):  
Soil Moisture ◽  
Soil Temperature ◽  
Soil Tillage ◽  
Soil Conditions ◽  
Reduced Tillage ◽  
No Tillage ◽  
Dry Soil ◽  
The Impact ◽  
Tillage Methods ◽  
Erosion Prevention

Inter-rows in vineyards are commonly tilled in order to control weeds and/or to conserve water. While impacts of tillage on earthworms are well studied in arable systems, very little is known from vineyards. In an experimental vineyard, the impact of four reduced tillage methods on earthworms was examined: rotary hoeing, rotary harrowing, grubbing and no tillage. According to an erosion prevention programme, tillage was applied every other inter-row only while alternating rows retained vegetated. Earthworms were extracted from the treated inter-rows 10, 36, 162 and 188 days after tillage. Across dates, tillage methods had no effect on overall earthworm densities or biomass. Considering each sampling date separately, earthworm densities were affected only at day 36 after tillage leading to lower densities under rotary hoeing (150.7 ± 42.5 worms/m<sup>2</sup>) and no tillage (117.3 ± 24.8 worms/m<sup>2</sup>) than under rotary harrowing (340.0 ± 87.4 worms/m<sup>2</sup>) and grubbing (242.7 ± 43.9 worms/m<sup>2</sup>). Time since tillage significantly increased earthworm densities or biomass, and affected soil moisture and temperature. Across sampling dates, earthworm densities correlated positively with soil moisture and negatively with soil temperature; individual earthworm mass increased with increasing time since tillage. It was concluded that reduced tillage in vineyards has little impact on earthworms when applied in spring under dry soil conditions.

Entomopathogenic nematode (Heterorhabditidae and Steinernematidae) spatial distribution in turfgrass

Parasitology ◽  
1996 ◽  
Vol 113 (5) ◽  
pp. 473-482 ◽  
Author(s):  
J. F. Campbell ◽  
E. Lewis ◽  
F. Yoder ◽  
R. Gaugler
Keyword(s):  
Spatial Distribution ◽  
Vertical Distribution ◽  
Entomopathogenic Nematodes ◽  
Entomopathogenic Nematode ◽  
Soil Surface ◽  
Nematode Species ◽  
Horizontal Distribution ◽  
Steinernema Carpocapsae ◽  
Foraging Strategies ◽  
Temporal And Spatial Distribution

SUMMARYUnderstanding the temporal and spatial distribution of entomopathogenic nematodes is essential for determining the role of these insect parasites in soil communities and ultimately for their use in suppression of pest insect populations. We measured the vertical and horizontal distribution of endemic populations of entomopathogenic nematodes (Steinernema carpocapsae and Heterorhabditis bacteriophord) in turfgrass. Vertical distribution was determined by taking soil cores every 3 h from 05.00 to 23.00 h, over 4 days, and dividing the cores into 8, 1 cm deep sections. Steinernema carpocapsae was recovered primarily near the soil surface: 50% of positive sections were recovered in the thatch or first 1 cm of soil. S. carpocapsae recovery was lower during the middle of the day and none were recovered in the upper section. H. bacteriophora was recovered uniformly throughout the top 8 cm of soil and its vertical distribution did not change over the course of the day. Horizontal distribution was measured as the number of nematodes recovered from cores taken from 12 randomly selected 0·3 × 0·8 m sections from within four 15·3 × 15·3 m plots. Samples were collected biweekly over a 9-month period. H. bacteriophora had a patchier distribution than S. carpocapsae and both nematode species had more patchy distributions then their potential hosts. Our results support the hypothesis that these two species of nematode utilize different foraging strategies; S. carpocapsae primarily a surface adapted ambusher and H. bacteriophora as a cruise forager.

scholarly journals The Effect of the Dry Line and Convective Initiation on Drought Evolution over Oklahoma during the 2011 Drought

2017 ◽  
Vol 2017 ◽  
pp. 1-16 ◽  
Author(s):  
Paul X. Flanagan ◽  
Jeffrey B. Basara ◽  
Bradley G. Illston ◽  
Jason A. Otkin
Keyword(s):  
Soil Moisture ◽  
Large Scale ◽  
Warm Season ◽  
Convective Initiation ◽  
Model Simulations ◽  
Variable Surface ◽  
Oklahoma Mesonet ◽  
Dry Conditions ◽  
Moisture Conditions ◽  
The Impact

Observations from the Oklahoma Mesonet and high resolution Weather Research and Forecasting model simulations were used to evaluate the effect that the dry line and large-scale atmospheric patterns had on drought evolution during 2011. Mesonet observations showed that a “dry” and “wet” pattern developed across Oklahoma due to anomalous atmospheric patterns. The location of the dry line varied due to this “dry” and “wet” pattern, with the average dry line location around 1.5° longitude further to the east than climatology. Model simulations were used to further quantify the impact of variable surface conditions on dry line evolution and convective initiation (CI) during April and May 2011. Specifically, soil moisture conditions were altered to depict “wet” and “dry” conditions across the domain by replacing the soil moisture values by each soil category’s porosity or wilting point value. Overall, the strength of the dry line boundary, its position, and subsequent CI were dependent on the modification of soil moisture. The simulations demonstrated that modifying soil moisture impacted the nature of the dry line and showed that soil moisture conditions during the first half of the warm season modified the dry line pattern and influenced the evolution and perpetuation of drought over Oklahoma.

PERFORMANCE OF ENTOMOPATHOGENIC NEMATODES ON NEOLEUCINODES ELEGANTALIS (GUENÉE) (LEPIDOPTERA: CRAMBIDAE)

2021 ◽  
Vol 18 (1) ◽  
pp. 205-215
Author(s):  
Dirceu Pratissoli ◽  
ALIXELHE PACHECO DAMASCENA ◽  
Débora Melo Ferreira Fragoso ◽  
José Romário De Carvalho ◽  
Amanda Carlos Túler ◽  
...  
Keyword(s):  
Integrated Pest Management ◽  
Pest Management ◽  
Entomopathogenic Nematodes ◽  
Nematode Species ◽  
Positive Control ◽  
Steinernema Carpocapsae ◽  
Pathogenicity Test ◽  
Distilled Water ◽  
Heterorhabditis Indica ◽  
Tomato Seedlings

The use of entomopathogenic nematodes in pest management is an alternative to reduce the yield and/or damage losses caused by pests in several crops. The present study aimed to evaluate the performance of Heterorhabditis indica (Nemata: Rhabditida) and Steinernema carpocapsae (Nemata: Rhabditida), in pre-pupae of Neoleucinodes elegantalis (Guenée) (Lepidoptera: Crambidae) and determine the temporal viability of the pathogenicity of S. carpocapsae applied to soil. The nematode species were diluted in distilled water to 50, 65, 83, 107, 138, 178, 229, 295, 380 and 500 infective juveniles per pre-pupae (IJs insect-1) of N. elegantalis.  The mortality of pre-pupa of N. elegantalis was higher as the concentrations of both studied species increased. The nematode S. carpocapsae was the most effective, causing mortality of 82.93% in the concentration of 65 IJs insect-1 and an LC50 of 24.32 IJs insect-1. In the pathogenicity test, S. carpocapsae was applied in the concentration of 100 JI/cm² in pots previously planted with tomato seedlings. As positive control was used tomato seedlings treated with distilled water. S. carpocapse presented soil viability of 24 days. Thus, S. carpocapsae can be an important tool in the integrated pest management (IPM) of N. elegantalis.

Mortality Response of Green June Beetle (Coleoptera: Scarabaeidae) to Four Species of Entomopathogenic Nematodes

1994 ◽  
Vol 29 (2) ◽  
pp. 268-275 ◽  
Author(s):  
Monica L. Townsend ◽  
Don C. Steinkraus ◽  
Donn T. Johnson
Keyword(s):  
Entomopathogenic Nematodes ◽  
Alimentary Tract ◽  
Nematode Species ◽  
Heterorhabditis Bacteriophora ◽  
Steinernema Carpocapsae ◽  
The Other ◽  
Mortality Response ◽  
Green June Beetle

Four species of entomopathogenic nematodes, Steinernema carpocapsae (Weiser) (All strain), S. feltiae (Filipjev) (NC strain), S. glaseri (Steiner), and Heterorhabditis bacteriophora Poinar, were tested in the laboratory for their effect on larvae of the green June beetle, Cotinus nitida L. When nematodes were injected into the foregut of larvae (ca. 1,000 nematodes per larva), S. carpocapsae, S. feltiae, S. glaseri, and H. bacteriophora caused similar mortality (65, 45, 65, and 63%, respectively). At a concentration of 10 nematodes per larva, S. carpocapsae produced significantly higher mortality (51%) than the other three nematode species. Increasing nematode concentrations resulted in only a slight increase in mortality of larvae injected perorally with any of the four nematode species. Water filtrates from whole nematodes or ground nematode tissue supernatants from S. carpocapsae and H. bacteriophora injected perorally into the alimentary tract did not kill green June beetle larvae. Thus, live nematodes appeared to be necessary to cause mortality. Subcuticular or peroral injections of S. carpocapsae or H. bacteriophora (1,000 nematodes per larva) produced similar mortality of green June beetle larvae ranging from 60 to 70%. Nematode-killed larvae were dissected (n=277) but only two cadavers contained live nematodes and nematodes did not successfully reproduce in any nematode-killed green June beetle larvae. Possible explanations for the failure of cadavers to produce nematode progeny are discussed.

Effect of soil temperature and moisture on soil test P with different extractants

2012 ◽  
Vol 92 (3) ◽  
pp. 537-542 ◽  
Author(s):  
Chunyu Song ◽  
Xingyi Zhang ◽  
Xiaobing Liu ◽  
Yuan Chen
Keyword(s):  
Soil Moisture ◽  
Soil Temperature ◽  
Test Methods ◽  
Soil Test ◽  
Soil P ◽  
Soil P Test ◽  
Soil Test P ◽  
Fertilization Level ◽  
Bray 1 ◽  
Soil Temperature And Moisture

Song, C., Zhang, X., Liu, X. and Chen, Y. 2012. Effect of soil temperature and moisture on soil test P with different extractants. Can. J. Soil Sci. 92: 537–542. Temperature and moisture are important factors affecting adsorption, transformation and the availability of soil phosphorus (P) to plants. The different temperatures and moisture contents at which soil is sampled might affect the results of soil test P (STP). In order to evaluate the effect of the temperature and moisture, as well as the fertilization level, on the results of soil test P, an incubation study involving three soil temperatures (5, 10, and 20°C), and three soil moisture contents (50, 70, 90% of field water-holding capacity) was conducted with Chinese Mollisols collected from four fertilization treatments in a long-term experiment in northeast China. Four soil P test methods, Mehlich 3, Morgan, Olsen and Bray 1 were used to determine STP after a 42-d incubation. The effect of temperature and moisture on STP varied among soil P tests. Averaged across the four fertilization treatments, the temperature had significant impact on STP, while the responses varied among soil P test methods. Mehlich 3, Morgan and Bray 1 STP decreased and Olsen STP increased with increase in temperature. Effect of soil moisture was only significant for Mehlich 3 P and Olsen P. Soil temperature had greater impact on STP than soil moisture content. The responses of the Olsen method to temperature differed from the other three methods tested. The interaction between soil temperature and soil moisture on soil test P was only significant for Mehlich 3 P. Fertilization level does not affect the STP in as a clear pattern as the temperature and moisture varied for all four methods. Consistent soil sampling conditions, especially the soil temperature, appear to be the first step to achieve a reliable STP for any soil P test.

scholarly journals Effects of Soil Temperature, Moisture, and Burial Depths on Carpogenic Germination of Sclerotinia sclerotiorum and S. minor

2008 ◽  
Vol 98 (10) ◽  
pp. 1144-1152 ◽  
Author(s):  
B. M. Wu ◽  
K. V. Subbarao
Keyword(s):  
Soil Moisture ◽  
Soil Temperature ◽  
Sclerotinia Sclerotiorum ◽  
Soil Water Potential ◽  
Conventional Tillage ◽  
Dry Period ◽  
Carpogenic Germination ◽  
Needed Information ◽  
Geographical Regions ◽  
Soil Temperature And Moisture

Extensive studies have been conducted on the carpogenic germination of Sclerotinia sclerotiorum, but carpogenic germination in S. minor has not been studied adequately. It remains unclear why apothecia of this pathogen have seldom been observed in nature. In this study, a new method was developed to produce apothecia in the absence of soil or sand, and carpogenic germination without preconditioning was recorded for 95 of the 96 S. sclerotiorum isolates tested. Carpogenic germination of the two species was compared under a variety of temperature, soil moisture, burial depths, and short periods of high temperature and low soil moisture. The optimal temperatures for rapid germination and for maximum germination rates were both lower for S. minor than for S. sclerotiorum. The temperature range for carpogenic germination was also narrower for S. minor than for S. sclerotiorum. A 5-day period at 30°C, either starting on the 10th or 20th day of incubation, did not significantly affect carpogenic germination of S. sclerotiorum. For both S. minor and S. sclerotiorum, the percentage of carpogenically germinated sclerotia increased as soil water potential increased from –0.3 to –0.01 MPa. In the greenhouse, a 10- or 20-day dry period completely arrested carpogenic germination of S. sclerotiorum, and new apothecia appeared after an interval of 35 days following rewetting, similar to the initial carpogenic germination regardless of when the dry period was imposed. In naturally infested fields, the number of sclerotia in 100 cc of soil decreased as depth increased from 0 to 10 cm before tillage, but became uniform between 0 and 10 cm after conventional tillage for both species. Most apothecia of S. minor were, however, produced from sclerotia located at a depth shallower than 0.5 cm while some apothecia of S. sclerotiorum were produced from sclerotia located as deep as 4 to 5 cm. These results provide the much needed information to assess the epidemiological roles of inoculum from sexual reproduction in diseases caused by the two Sclerotinia species in different geographical regions. However, more studies on effects of shorter and incompletely dry periods are still needed to predict production of apothecia of S. sclerotiorum in commercial fields under fluctuating soil temperature and moisture.

Effect of soil moisture and temperature on N2O and CO2 concentrations in soil irrigated with purified wastewater

2013 ◽  
Vol 27 (3) ◽  
pp. 299-304 ◽  
Author(s):  
M. Nosalewicz ◽  
Z. Stępniewska ◽  
A. Nosalewicz
Keyword(s):  
Carbon Dioxide ◽  
Nitrous Oxide ◽  
Soil Moisture ◽  
Soil Temperature ◽  
Similar Pattern ◽  
Organic Soil ◽  
Organic Soils ◽  
Depth Range ◽  
Depth Ranges ◽  
Soil Temperature And Moisture

Abstract Flooded organic soils are potentially important sources of greenhouse gases. The effect of soil temperature and moisture on the concentration of N2O and CO2 at two depths of organic soil flooded with two doses of purified wastewater was studied. Nitrous oxide concentrations at the 10-30 cm depth range were generally increased with an increase in soil moisture, showing dependence on the aeration status of soil. The maximum values of N2O concentrations were higher at the 50-100 than 10-30 cm depth range, but a similar pattern of increasing maximum values of N2O concentration with an increasing input of nitrogen in treatments at both depth ranges was observed. The maximum concentrations of carbon dioxide within the 50-100 cm depth range remained at a similar level in all treatments reaching 7.1-7.7%, which indicated weak relations with the input of water and nitrogen at this depth range. We conclude that the N2O and CO2 concentrations at 10-30 cm depths in the examined organic soil flooded with 600mm year-1 of purified wastewater exhibited a similar level as the concentrations in soil watered only by precipitation.

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