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Saad AM, Salem HM, El-Tahan AM, El-Saadony MT, Alotaibi SS, El-Shehawi AM, Abd El-Mageed TA, Taha AE, Alkahtani MA, Ezzat Ahmed A, Swelum AA. Biological control: An effective approach against nematodes using black pepper plants (Piper nigrum L.). Saudi J Biol Sci 2022; 29:2047-2055. [PMID: 35531173 PMCID: PMC9073003 DOI: 10.1016/j.sjbs.2022.01.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 12/05/2021] [Accepted: 01/02/2022] [Indexed: 12/29/2022] Open
Abstract
Black pepper (Piper nigrum L.) is one of the oldest spices in the world, additionally, it is highly demanded. Several biotic and abiotic variables pose black pepper production worldwide. Plant-parasitic nematodes play a key role among biotic factors, causing considerable economic losses and affecting the production. Different synthetic nematicides were used for controlling plant nematodes, however the majority of pesticides have been pulled from the market due to substantial non-target effects and environmental risks. As a result, the search for alternative eco-friendly agents for controlling plant-parasitic nematodes populations. Microbial agents are a precious option. In this review the bacterial and fungal agents used as an alternative nematicides, they were studied and confirmed as essential anti-microbial agents against plant nematodes which infected Piper nigrum L. This work examines the most common plant nematodes infected Piper nigrum L., with a focus on root knot and burrowing nematodes, in addition, how to control plant parasitic nematodes using microorganisms.
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Affiliation(s)
- Ahmed M. Saad
- Biochemistry Department, Faculty of Agriculture, Zagazig University, Zagazig 44511, Egypt
- Corresponding author.
| | - Heba M. Salem
- Department of Poultry Diseases, Faculty of Veterinary Medicine, Cairo University, 12211 Giza, Egypt
| | - Amira M. El-Tahan
- Plant Production Department, Arid Lands Cultivation Research Institute, The City of Scientific, Research and Technological Applications, SRTA-City. Borg El Arab, Alexandria, Egypt
| | - Mohamed T. El-Saadony
- Department of Agricultural Microbiology, Faculty of Agriculture, Zagazig University, Zagazig 4451, Egypt
| | - Saqer S. Alotaibi
- Department of Biotechnology, College of Science, Taif University, P.O. Box 11099, Taif 21944, Saudi Arabia
| | - Ahmed M. El-Shehawi
- Department of Biotechnology, College of Science, Taif University, P.O. Box 11099, Taif 21944, Saudi Arabia
| | - Taia A. Abd El-Mageed
- Soil and Water Department, Faculty of Agriculture, Fayoum University, Fayoum 63514, Egypt
| | - Ayman E. Taha
- Department of Animal Husbandry and Animal Wealth Development, Faculty of Veterinary Medicine, Alexandria University, Edfina 22758, Egypt
| | - Mohammed A. Alkahtani
- Biology Department, College of Science, King Khalid University, 61413 Abha, Saudi Arabia
| | - Ahmed Ezzat Ahmed
- Biology Department, College of Science, King Khalid University, 61413 Abha, Saudi Arabia
- Department of Theriogenology, Faculty of Veterinary Medicine, South Valley University, 83523 Qena, Egypt
| | - Ayman A. Swelum
- Department of Animal Production, College of Food and Agriculture Sciences, King Saud University, PO Box 2460, Riyadh 11451, Saudi Arabia
- Department of Theriogenology, Faculty of Veterinary Medicine, Zagazig University, Sharkia 44519, Egypt
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Zhou D, Xu J, Dong J, Li H, Wang D, Gu J, Zhang KQ, Zhang Y. Historical Differentiation and Recent Hybridization in Natural Populations of the Nematode-Trapping Fungus Arthrobotrys oligospora in China. Microorganisms 2021; 9:1919. [PMID: 34576814 PMCID: PMC8465350 DOI: 10.3390/microorganisms9091919] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 09/06/2021] [Accepted: 09/07/2021] [Indexed: 01/10/2023] Open
Abstract
Maintaining the effects of nematode-trapping fungi (NTF) agents in order to control plant-parasitic nematodes (PPNs) in different ecological environments has been a major challenge in biological control applications. To achieve such an objective, it is important to understand how populations of the biocontrol agent NTF are geographically and ecologically structured. A previous study reported evidence for ecological adaptation in the model NTF species Arthrobotrys oligospora. However, their large-scale geographic structure, patterns of gene flow, their potential phenotypic diversification, and host specialization remain largely unknown. In this study, we developed a new panel of 20 polymorphic short tandem repeat (STR) markers and analyzed 239 isolates of A. oligospora from 19 geographic populations in China. In addition, DNA sequences at six nuclear gene loci and strain mating types (MAT) were obtained for these strains. Our analyses suggest historical divergence within the A. oligospora population in China. The genetically differentiated populations also showed phenotypic differences that may be related to their ecological adaptations. Interestingly, our analyses identified evidence for recent dispersion and hybridization among the historically subdivided geographic populations in nature. Together, our results indicate a changing population structure of A. oligospora in China and that care must be taken in selecting the appropriate strains as biocontrol agents that can effectively reproduce in agriculture soil while maintaining their nematode-trapping ability.
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Affiliation(s)
- Duanyong Zhou
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Key Laboratory for Southwest Microbial Diversity of the Ministry of Education, Yunnan University, Kunming 650032, China; (D.Z.); (J.D.); (H.L.); (D.W.)
- School of Life Science, Yunnan University, Kunming 650032, China;
- School of Biology and Chemistry, Xingyi Normal University for Nationalities, Xingyi 562400, China
| | - Jianping Xu
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Key Laboratory for Southwest Microbial Diversity of the Ministry of Education, Yunnan University, Kunming 650032, China; (D.Z.); (J.D.); (H.L.); (D.W.)
- Department of Biology, McMaster University, Hamilton, ON L8S 4K1, Canada
| | - Jianyong Dong
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Key Laboratory for Southwest Microbial Diversity of the Ministry of Education, Yunnan University, Kunming 650032, China; (D.Z.); (J.D.); (H.L.); (D.W.)
- School of Life Science, Yunnan University, Kunming 650032, China;
| | - Haixia Li
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Key Laboratory for Southwest Microbial Diversity of the Ministry of Education, Yunnan University, Kunming 650032, China; (D.Z.); (J.D.); (H.L.); (D.W.)
- School of Life Science, Yunnan University, Kunming 650032, China;
| | - Da Wang
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Key Laboratory for Southwest Microbial Diversity of the Ministry of Education, Yunnan University, Kunming 650032, China; (D.Z.); (J.D.); (H.L.); (D.W.)
- School of Life Science, Yunnan University, Kunming 650032, China;
| | - Juan Gu
- School of Life Science, Yunnan University, Kunming 650032, China;
| | - Ke-Qin Zhang
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Key Laboratory for Southwest Microbial Diversity of the Ministry of Education, Yunnan University, Kunming 650032, China; (D.Z.); (J.D.); (H.L.); (D.W.)
| | - Ying Zhang
- State Key Laboratory for Conservation and Utilization of Bio-Resources in Yunnan, Key Laboratory for Southwest Microbial Diversity of the Ministry of Education, Yunnan University, Kunming 650032, China; (D.Z.); (J.D.); (H.L.); (D.W.)
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Saumell CA, Fernández AS, Fusé LA, Rodríguez M, Sagüés MF, Iglesias LE. Nematophagous fungi from decomposing cattle faeces in Argentina. Rev Iberoam Micol 2015; 32:252-6. [DOI: 10.1016/j.riam.2014.09.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2013] [Revised: 07/24/2014] [Accepted: 09/16/2014] [Indexed: 11/29/2022] Open
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Lambers H, Bishop JG, Hopper SD, Laliberté E, Zúñiga-Feest A. Phosphorus-mobilization ecosystem engineering: the roles of cluster roots and carboxylate exudation in young P-limited ecosystems. ANNALS OF BOTANY 2012; 110:329-48. [PMID: 22700940 PMCID: PMC3394658 DOI: 10.1093/aob/mcs130] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2012] [Accepted: 05/17/2012] [Indexed: 05/20/2023]
Abstract
BACKGROUND Carboxylate-releasing cluster roots of Proteaceae play a key role in acquiring phosphorus (P) from ancient nutrient-impoverished soils in Australia. However, cluster roots are also found in Proteaceae on young, P-rich soils in Chile where they allow P acquisition from soils that strongly sorb P. SCOPE Unlike Proteaceae in Australia that tend to proficiently remobilize P from senescent leaves, Chilean Proteaceae produce leaf litter rich in P. Consequently, they may act as ecosystem engineers, providing P for plants without specialized roots to access sorbed P. We propose a similar ecosystem-engineering role for species that release large amounts of carboxylates in other relatively young, strongly P-sorbing substrates, e.g. young acidic volcanic deposits and calcareous dunes. Many of these species also fix atmospheric nitrogen and release nutrient-rich litter, but their role as ecosystem engineers is commonly ascribed only to their diazotrophic nature. CONCLUSIONS We propose that the P-mobilizing capacity of Proteaceae on young soils, which contain an abundance of P, but where P is poorly available, in combination with inefficient nutrient remobilization from senescing leaves allows these species to function as ecosystem engineers. We suggest that diazotrophic species that colonize young soils with strong P-sorption potential should be considered for their positive effect on P availability, as well as their widely accepted role in nitrogen fixation. Their P-mobilizing activity possibly also enhances their nitrogen-fixing capacity. These diazotrophic species may therefore facilitate the establishment and growth of species with less-efficient P-uptake strategies on more-developed soils with low P availability through similar mechanisms. We argue that the significance of cluster roots and high carboxylate exudation in the development of young ecosystems is probably far more important than has been envisaged thus far.
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Affiliation(s)
- Hans Lambers
- School of Plant Biology, University of Western Australia, Crawley, WA 6009, Australia.
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Costa SR, Kerry BR, Bardgett RD, Davies KG. Interactions between nematodes and their microbial enemies in coastal sand dunes. Oecologia 2012; 170:1053-66. [DOI: 10.1007/s00442-012-2359-z] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2011] [Accepted: 05/02/2012] [Indexed: 11/24/2022]
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Wachira P, Mibey R, Okoth S, Kimenju J, Kiarie J. Diversity of nematode destroying fungi in Taita Taveta, Kenya. FUNGAL ECOL 2009. [DOI: 10.1016/j.funeco.2008.11.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Ram K, Preisser EL, Gruner DS, Strong DR. Metapopulation dynamics override local limits on long-term parasite persistence. Ecology 2009; 89:3290-7. [PMID: 19137936 DOI: 10.1890/08-0228.1] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
A simple null model, particularly germane to small and vulnerable organisms such as parasites, is that local conditions set a stage upon which larger-scale dynamics play out. Soil moisture strongly influences survival of entomopathogenic nematodes (EPN), which in turn drive trophic cascades by protecting vegetation from root-feeding herbivores. In this study, we examine the mechanisms responsible for patchy occurrence of an entomopathogenic nematode, Heterorhabditis marelatus, in a California coastal prairie. One hypothesis proposes that biotic factors such as competition and natural enemies could regulate occurrence of EPN populations. We found that fungi and other enemies of EPN, although locally potent, did not explain the patterns of incidence across sites. Abiotic factors also have strong effects on EPN persistence, especially for vulnerable free-living stages. Thus, we tested the hypothesis that patchy occurrence of EPN on a large landscape was driven by differences in soil moisture. Our research uses long-term data on nematode incidence in combination with a landscape-level experiment to demonstrate the lack of a correlation between soil moisture and long-term persistence. A year-long experiment showed EPN mortality was weakly correlated with soil moisture among our study sites. Thirteen years of data, however, showed that colonization rates were highly correlated with long-term persistence. Sites with highest long-term persistence experienced the highest rates of rhizosphere colonization, extinction, and turnover. As a result, we concluded that metapopulation dynamics override limitations set by local and short-term abiotic conditions to determine long-term persistence in this parasite-driven trophic cascade.
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Affiliation(s)
- Karthik Ram
- Section of Evolution and Ecology, University of California, Davis, California 95616, USA.
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Nguyen VL, Bastow JL, Jaffee BA, Strong DR. Response of nematode-trapping fungi to organic substrates in a coastal grassland soil. ACTA ACUST UNITED AC 2007; 111:856-62. [PMID: 17662588 DOI: 10.1016/j.mycres.2007.04.009] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2006] [Revised: 01/30/2007] [Accepted: 04/27/2007] [Indexed: 11/29/2022]
Abstract
To understand why Arthrobotrys oligospora and other nematode-trapping fungi are common and sometimes abundant in the coastal grassland soils of the Bodega Marine Reserve (BMR, Sonoma County, CA), we examined how resident trapping fungi responded to the addition of eight organic substrates (lupine leaves, grass leaves, dead isopods, dead moth larvae, isopod faeces, deer faeces, shrimp shells, and powdered chitin). We were especially interested in the effects of dead isopods because isopods are abundant at BMR and because previous studies had documented strong responses of A. oligospora to other arthropods (dead moth larvae). Soil from BMR was packed into vials (40 g dry mass equivalent per vial with water potential at -230 kPa and bulk density at 0.9 gcm(-3)), and one substrate or no substrate was added to the soil surface. After 30 d at 20 degrees C, trapping fungi were quantified by dilution plating and most probable number procedures. The response of A. oligospora was inversely related to substrate carbon:nitrogen (C:N) ratio: substrates with low C:N ratios (dead isopods, lupine leaves, dead moth larvae) usually caused large increases in A. oligospora whereas those with higher C:N ratios (isopod faeces, deer faeces, grass leaves) did not. An exception was chitin powder, which had a low C:N ratio, but which did not cause A. oligospora to proliferate. Responses of A. oligospora were directly related to the quantity of nitrogen added with each substrate, and those substrates that caused large increases in resident nematodes usually caused large increases in A. oligospora. Other trapping fungi did not respond as strongly as A. oligospora.
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Affiliation(s)
- Vi L Nguyen
- Department of Nematology, University of California at Davis, Davis, CA 95616, USA
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Abstract
Interest in facilitative predator plant interactions has focused upon above-ground systems. Underground physical conditions are distinctive, however, and we provide evidence that bush lupine, Lupinus arboreus, facilitates the survival of the predatory nematode Heterorhabditis marelatus. Because H. marelatus is prone to desiccation and lupines maintain a zone of moist soil around their taproots even during dry periods, we hypothesized that dry-season nematode survival under lupines might be higher than in the surrounding grasslands. We performed field surveys and measured nematode survival in lupine and grassland rhizospheres under wet- and dry-season conditions. Nematodes survived the crucial summer period better under lupines than in grasslands; however, this advantage disappeared in wet, winter soils. Modeling the probability of nematode population extinction showed that, while even large nematode cohorts were likely to go extinct in grasslands, even small cohorts in lupine rhizospheres were likely to survive until the arrival of the next prey generation. Because this nematode predator has a strong top-down effect on lupine survival via its effect on root-boring larvae of the ghost moth Hepialus californicus, this facilitative interaction may enable a belowground trophic cascade. Similar cases of predator facilitation in seasonally stressful environments are probably common in nature.
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Affiliation(s)
- Evan L Preisser
- Center for Population Biology, University of California, Davis 95616, USA.
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Dugaw CJ, Preisser EL, Hastings A, Strong DR. Widening the window of persistence in seasonal pathogen–host systems. Theor Popul Biol 2005; 68:267-76. [PMID: 16085188 DOI: 10.1016/j.tpb.2005.05.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2005] [Revised: 05/25/2005] [Accepted: 05/31/2005] [Indexed: 11/18/2022]
Abstract
Local instability of exploiter-victim systems is well-known in both theory and in nature. Victims can be too sparse to support exploiter reproduction (under-exploitation) or they can be too readily driven to extinction (over-exploitation). Exploiters of seasonal resources face the additional challenge of surviving periods when victims are rare or unavailable. We formulate a fully stochastic model of highly seasonal pathogen-host dynamics and explore the interactions between an entomopathogenic nematode and its lepidopteran host. Our model suggests that if nematode populations experience the high rates of mortality predicted by short-term laboratory experiments, the paired threats of under- and over-exploitation should preclude the long-term persistence of this exploiter-victim system. We measured nematode mortality rates in the field and found that long-term mortality is lower than that predicted by short-term experiments. Incorporation of this new data into our model produces long-term persistence of local nematode populations across a range of initial nematode densities.
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Affiliation(s)
- Christopher J Dugaw
- Department of Mathematics, University of California Davis, One Shields Avenue, Davis, CA 95616, USA.
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Rosenheim JA, Glik TE, Goeriz RE, Rämert B. LINKING A PREDATOR'S FORAGING BEHAVIOR WITH ITS EFFECTS ON HERBIVORE POPULATION SUPPRESSION. Ecology 2004. [DOI: 10.1890/03-0825] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Rosenheim JA, Corbett A. OMNIVORY AND THE INDETERMINACY OF PREDATOR FUNCTION: CAN A KNOWLEDGE OF FORAGING BEHAVIOR HELP? Ecology 2003. [DOI: 10.1890/02-0469] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Strong DR, Whipple AV, Child AL, Dennis B. MODEL SELECTION FOR A SUBTERRANEAN TROPHIC CASCADE: ROOT-FEEDING CATERPILLARS AND ENTOMOPATHOGENIC NEMATODES. Ecology 1999. [DOI: 10.1890/0012-9658(1999)080[2750:msfast]2.0.co;2] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Jaffee BA. Enchytraeids and nematophagous fungi in tomato fields and vineyards. PHYTOPATHOLOGY 1999; 89:398-406. [PMID: 18944753 DOI: 10.1094/phyto.1999.89.5.398] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
ABSTRACT I tested the hypothesis that exclusion of enchytraeids and microarthropods in agricultural fields improves establishment of two nematophagous fungi. Soil was collected from three tomato fields and two vineyards and either heat-treated (2 h at 60 degrees C) or not. Alginate pellets containing hyphae of the fungi Hirsutella rhossiliensis or Monacrosporium gephyropagum were added to the soil, which was packed into cages (PVC pipe, 80-cm(3) volume) sealed with fine (20 mum) or coarse (480 mum) mesh. Cages were buried 22 cm deep in the same fields from which the soil had been collected. After 7 to 50 days, the cages were recovered and fungi and fauna quantified. Fine mesh largely excluded enchytraeids, collembolans, and mites but rarely affected fungus numbers. In contrast, heat treatment of soil rarely affected enchytraeids, collembolans, or mites but frequently increased fungus numbers, regardless of mesh size. The data are inconsistent with the initial hypothesis but are consistent with the idea that organisms narrower than 20 mum interfere with fungal growth from the pellets.
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Jaffee BA, Ferris H, Scow KM. Nematode-trapping fungi in organic and conventional cropping systems. PHYTOPATHOLOGY 1998; 88:344-350. [PMID: 18944958 DOI: 10.1094/phyto.1998.88.4.344] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
ABSTRACT Nematode-trapping fungi, nematodes, and microbial biomass were quantified in conventionally and organically managed field plots in the Sustainable Agriculture Farming Systems Project at the University of California at Davis. There were four replicate plots (0.135 ha per plot) for each management system, and plots were sampled three times each year for 2 years. The hypothesis that nematode-trapping fungi would be more abundant in organically managed plots was partially supported: the number of species of nematode-trapping fungi was slightly but significantly greater in organic than in conventional plots, two species (Arthrobotrys dactyloides and Nematoctonus leiosporus) were detected more frequently in organic plots, and the population densities of A. dactyloides and N. leiosporus were greater in organic than in conventional plots. Two other species (A. haptotyla and A. thaumasia), however, tended to be more numerous in conventional than in organic plots, and the total density of nematode-trapping fungi was similar in organic and conventional plots. Bacterivorous nematodes were more abundant and microbial biomass (substrate-induced respiration) was greater in organic than in conventional plots. Suppression of the root-knot nematode Meloidogyne javanica, as measured in a bioassay, was not related to management system or population density of nematode-trapping fungi but was positively related to microbial biomass.
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Rosenheim JA. Higher-order predators and the regulation of insect herbivore populations. ANNUAL REVIEW OF ENTOMOLOGY 1998; 43:421-447. [PMID: 9444753 DOI: 10.1146/annurev.ento.43.1.421] [Citation(s) in RCA: 175] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Empirical research has not supported the prediction that populations of terrestrial herbivorous arthropods are regulated solely by their natural enemies. Instead, both natural enemies (top-down effects) and resources (bottom-up effects) may play important regulatory roles. This review evaluates the hypothesis that higher-order predators may constrain the top-down control of herbivore populations. Natural enemies of herbivorous arthropods generally are not top predators within terrestrial food webs. Insect pathogens and entomopathogenic nematodes inhabiting the soil may be attacked by diverse micro- and mesofauna. Predatory and parasitic insects are attacked by their own suite of predators, parasitoids, and pathogens. The view of natural enemy ecology that has emerged from laboratory studies, where natural enemies are often isolated from all elements of the biotic community except for their hosts or prey, may be an unreliable guide to field dynamics. Experimental work suggests that interactions of biological control agents with their own natural enemies can disrupt the effective control of herbivore populations. Disruption has been observed experimentally in interactions of bacteria with bacteriophages, nematodes with nematophagous fungi, parasitoids with predators, parasitoids with hyperparasitoids, and predators with other predators. Higher-order predators have been little studied; manipulative field experiments will be especially valuable in furthering our understanding of their roles in arthropod communities.
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Affiliation(s)
- J A Rosenheim
- Department of Entomology, University of California, Davis 95616, USA
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