scholarly journals Parasitism of Sedentary Stages of Heterodera glycines by Isolates of a Sterile Nematophagous Fungus

1999 ◽  
Vol 89 (12) ◽  
pp. 1193-1199 ◽  
Author(s):  
Patricia Timper ◽  
Robert D. Riggs ◽  
Devany L. Crippen
Keyword(s):  
Heterodera Glycines ◽  
Biological Control Agent ◽  
Control Agent ◽  
Nematophagous Fungus ◽  
Infested Soil ◽  
Young Females ◽  
Heat Treated ◽  
Nematode Eggs ◽  
Soybean Plants ◽  
Gravid Females

Isolates of a sterile fungus designated ARF (Arkansas fungus) can be separated into two groups, ARF-C and ARF-L, that differ morphologically and in their ability to suppress numbers of Heterodera glycines on soybean. Our objectives were to determine if the two ARF groups differed in their ability to parasitize juveniles, females, and eggs in the rhizo-sphere of soybean and to proliferate in soil. The experiments were conducted in a greenhouse using soil infested with homogenized ARF mycelium. The ARF-L isolates parasitized more juveniles and young females than did the ARF-C isolates. Suppression of these stages was 67% for ARF-L and 12% for ARF-C isolates 14 days after nematode inoculation. When soybean plants containing gravid females were transplanted into fungus-infested soil, ARF-L isolates parasitized 55 to 98% of nematode eggs, whereas ARF-C isolates parasitized 0 to 22%. In both heat-treated and nonheated soil, the biomass of mycelial mats, a measure of relative proliferation, tended to be greater for ARF-L than for ARF-C isolates. The ability of ARF-L isolates to parasitize a large percentage of both pre-reproductive stages and eggs of H. glycines may contribute to its effectiveness as a biological control agent.

scholarly journals Taxonomic Resolution of the Nematophagous Fungal Isolate ARF18 via Genome Sequencing

2017 ◽  
Vol 5 (34) ◽  
Author(s):  
Sandeep Sharma ◽  
Alex Z. Zaccaron ◽  
John B. Ridenour ◽  
Amy Bradshaw ◽  
Terry L. Kirkpatrick ◽  
...  
Keyword(s):  
Soybean Cyst Nematode ◽  
Heterodera Glycines ◽  
Novel Species ◽  
Biological Control Agent ◽  
Draft Genome ◽  
Control Agent ◽  
Nematophagous Fungus ◽  
Cyst Nematode ◽  
Fungal Isolate ◽  
Taxonomic Resolution

ABSTRACT The taxonomically uncharacterized nematophagous fungus ARF18, which parasitizes cysts, juveniles, and adults of the soybean cyst nematode (Heterodera glycines), was proposed as a nematode biological control agent in 1991. A 46.3-Mb draft genome sequence of this fungus is presented, and a tentative taxonomic identification as a novel species of Brachyphoris is proposed.

Ecological considerations for the use of the nematophagous fungus, Verticillium chlamydosporium, to control plant parasitic nematodes

1995 ◽  
Vol 73 (S1) ◽  
pp. 65-70 ◽  
Author(s):  
B. R. Kerry
Keyword(s):  
Biological Control ◽  
Biological Control Agent ◽  
Control Plant ◽  
Nematode Species ◽  
Control Agent ◽  
Nematophagous Fungus ◽  
Effective Control ◽  
Parasitic Nematodes ◽  
Root Knot Nematodes ◽  
Verticillium Chlamydosporium

The nematophagous fungus, Verticillium chlamydosporium, has considerable potential as a biological control agent for root-knot nematodes on a range of crops. The fungus is a general facultative parasite that attacks the eggs of several nematode species. The biology of the fungus is reviewed and the need for a detailed understanding of its ecology for its rational use as a biological control agent is highlighted. Isolates of the fungus must colonize the rhizosphere to be effective control agents. Plants differ in their ability to support the fungus and greatest control is achieved on those cultivars that support abundant growth of the fungus but produce only limited galling in response to nematode attack. On such plants, most eggs produced by nematodes are exposed to parasitism by this nematophagous fungus in the rhizosphere. Key words: biological control, nematophagous fungi, root-knot nematodes, Verticillium chlamydosporium.

scholarly journals Exposure of Toxocara canis eggs to Purpureocillium lilacinum as a biocontrol strategy: an experimental model evaluation

2019 ◽  
Vol 28 (1) ◽  
pp. 91-96 ◽  
Author(s):  
Fernando de Souza Maia Filho ◽  
Anelise de Oliveira da Silva Fonseca ◽  
Júlia de Souza Silveira Valente ◽  
Cristiane Telles Baptista ◽  
Andrios da Silva Moreira ◽  
...  
Keyword(s):  
Biological Control ◽  
Experimental Infection ◽  
Biological Control Agent ◽  
Toxocara Canis ◽  
Control Agent ◽  
Nematophagous Fungus ◽  
Control Group ◽  
Fungal Exposure ◽  
Purpureocillium Lilacinum ◽  
Larval Recovery

Abstract Purpureocillium lilacinum is a nematophagous fungus used in biological control against some parasites, including Toxocara canis. This study researched the infectivity of embryonated T. canis eggs after exposure to the fungus P. lilacinum. T. canis eggs were exposed to P. lilacinum for 15 or 30 days and subsequently administered to Swiss mice (n=20). Control group consisted of mice who received T. canis embryonated eggs without fungal exposure. Forty-eight hours after infection, heart, lung, and liver from animals of each group were collected to assess larval recovery. The organs of mice that received embryonated eggs exposed to the fungus showed a lower average larval recovery (P<0.05) suggesting that exposure of T. canis eggs to P. lilacinum was able to reduce experimental infection. Under the evaluated conditions, the interaction time between the fungus and the parasite eggs was not a significant factor in larvae recovery. P. lilacinum may be considered a promising T. canis biological control agent. However, further studies are needed to determine a protocol for the use of this fungus as a biological control agent.

scholarly journals Possible application of a nematophagous fungus as a biological control agent of parasitic nematodes on commercial sheep farms in South Africa

2002 ◽  
Vol 73 (1) ◽  
Author(s):  
M. Faedo ◽  
R.C. Krecek
Keyword(s):  
South Africa ◽  
Biological Control ◽  
Biological Control Agent ◽  
Control Strategies ◽  
Control Agent ◽  
Nematophagous Fungus ◽  
Parasitic Nematodes ◽  
Parasite Control ◽  
Pasture Management ◽  
Clinical Assay

Biological control of parasitic nematodes of livestock is currently under development and represents another tool that may be integrated into helminth parasite control strategies. This paper presents a brief introduction to commercial sheep farming in South Africa and currently available nematode parasite control methods. These include the FAMACHA(r) clinical assay, strategies of pasture management, dilution of resistant worm species by introduction of susceptible worms, breed resistant sheep and nutritional supplementation. The purpose of this paper is to outline the principles of biological control using nematophagous fungi and how it may be applied on sheep farms in South Africa.

scholarly journals FUNCTIONAL RESPONSE OF HABROBRACON HEBETOR SAY (HYM.: BRACONIDAE) TO MEDITERRANEAN FLOUR MOTH (ANAGASTA KUEHNIELLA ZELLER), IN RESPONSE TO PESTICIDES

2013 ◽  
Vol 53 (4) ◽  
pp. 399-403 ◽  
Author(s):  
Vahid Mahdavi ◽  
Moosa Saber
Keyword(s):  
Biological Control ◽  
Functional Response ◽  
Biological Control Agent ◽  
Host Density ◽  
Field Studies ◽  
Control Agent ◽  
Habrobracon Hebetor ◽  
Young Females ◽  
Anagasta Kuehniella ◽  
Chemical Material

Abstract The functional response is a behavioral phenomena defined as the relation between the parasitized host per each parasitoid and host density. This phenomenon can be useful in assessing parasitoid efficiency for the biological control of the host. Parasitoid wasps are most important insects and they play a significant role in the natural control of pests via their parasitism activities. In this study, the effects of diazinon and malathion were evaluated on the functional response of Habrobracon hebetor Say to different densities of last instar larvae of Anagasta kuehniella Zeller. Young adult females (< 24 h old) of the parasitoid were exposed to LC30 values of pesticides. Host densities of 2, 4, 8, 16, 32, and 64 were offered, to treated young females for 24 h in 10 cm Petri dishes. At this point, the parasitism data were recorded. The experiments were conducted in eight replications. The functional response was type Ш in the control and insecticide treatments. Searching efficiency in the control, diazinon and malathion-treated wasps were 0.008±0.002, 0.003±0.002, and 0.004±0.002 h-1, handling times were 1.38±0.1, 7.95±0.91, and 6.4±0.81 h, respectively. Diazinon and malathion had the highest and the lowest effect on searching efficiency of H. hebetor, respectively. After conducting advanced field studies, it was found that malathion may be used as a compatible chemical material with biological control agent in IPM programs.

Administration of the nematophagous fungus Duddingtonia flagrans to goats: an evaluation of the impact of this fungus on the degradation of faeces and on free-living soil nematodes

2011 ◽  
Vol 86 (1) ◽  
pp. 95-103 ◽  
Author(s):  
C. Paraud ◽  
R. Lorrain ◽  
I. Pors ◽  
C. Chartier
Keyword(s):  
Biological Control Agent ◽  
Control Agent ◽  
Nematophagous Fungus ◽  
Soil Nematode ◽  
Duddingtonia Flagrans ◽  
Free Living ◽  
Rate Analysis ◽  
Nematode Parasites ◽  
The Impact ◽  
Different Doses

AbstractThe environmental impact of Duddingtonia flagrans, a potential biological control agent for nematode parasites, was tested in a 2-year-plot study using goat faeces. The trial assessed the impact of fungal presence on the disintegration of faeces and on non-target, free-living soil nematode populations. Three groups of goats experimentally infected by Trichostrongylus colubriformis received three different doses of D. flagrans chlamydospores (0 chlamydospores/kg body weight (BW), 0.5 × 106 chlamydospores/kg BW or 5 × 106 chlamydospores/kg BW). One hundred grams of faeces containing T. colubriformis eggs and D. flagrans chlamydospores at three different concentrations were deposited on pasture plots on four different occasions: May 2003, September 2003, June 2004 and September 2004. Faeces were weighed 2, 4, 6, 8, 10, 12, 14, 16, 18 and 20 weeks after deposit and immediately afterwards replaced to their initial positions. In addition, soil samples were taken just below faecal deposits to evaluate the impact of fungal presence on non-target free-living nematodes. Results showed that there was no treatment effect on the pellet degradation rate. Analysis of soil nematode fauna failed to demonstrate any effect of the dose rate of 0.5 × 106 chlamydospores/kg BW, while a reduction of the number of free-living nematodes was seen for the maximal chlamydospore concentration at autumn sets.

Population biology and biological control of nematodes

1992 ◽  
Vol 38 (5) ◽  
pp. 359-364 ◽  
Author(s):  
B. A. Jaffee
Keyword(s):  
Biological Control ◽  
Population Biology ◽  
Biological Control Agent ◽  
Host Density ◽  
Control Agent ◽  
Nematophagous Fungus ◽  
Future Research ◽  
Dynamics Modeling ◽  
Nematode Density ◽  
Minimum Number

We studied the population biology of the nematophagous fungus Hirsutella rhossiliensis to understand its potential as a biological control agent. Because the fungus is an infectious and transmissible parasite, we framed our study within an epidemiological context. Field observations, theory, and experiments demonstrated that (i) parasitism of nematodes by H. rhossiliensis is dependent on nematode density, (ii) local populations of the fungus will go extinct unless supplied with some minimum number of nematodes (the host threshold density), and (iii) natural epidemics of this fungus in populations of nematodes develop slowly and only after long periods of high host density. Additional in-depth research on population biology is needed to explain other biological control systems and to guide future research. The most effective research will combine field observation, theory, and experimentation. Key words: density-dependent parasitism, host-parasite dynamics, modeling, nematophagous fungi.

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