Strategies in herbivory by mammals revisited: The role of liver metabolism in a juniper specialist (Neotoma stephensi) and a generalist (Neotoma albigula)

Although herbivory is widespread among mammals, few species have adopted a strategy of dietary specialization. Feeding on a single plant species often exposes herbivores to high doses of plant secondary metabolites (PSMs), which may exceed the animal's detoxification capacities. Theory predicts that specialists will have unique detoxification mechanisms to process high levels of dietary toxins. To evaluate this hypothesis, we compared liver microsomal metabolism of a juniper specialist, Neotoma stephensi (diet >85% juniper), to a generalist, N. albigula (diet ≤30% juniper). Specifically, we quantified the concentration of a key detoxification enzyme, cytochrome P450 2B (CYP2B) in liver microsomes, and the metabolism of α‐pinene, the most abundant terpene in the juniper species consumed by the specialist woodrat. In both species, a 30% juniper diet increased the total CYP2B concentration (2–3×) in microsomes and microsomal α‐pinene metabolism rates (4‐fold). In N. stephensi, higher levels of dietary juniper (60% and 100%) further induced CYP2B and increased metabolism rates of α‐pinene. Although no species‐specific differences in metabolism rates were observed at 30% dietary juniper, total microsomal CYP2B concentration was 1.7× higher in N. stephensi than in N. albigula (p < .01), suggesting N. stephensi produces one or more variant of CYP2B that is less efficient at processing α‐pinene. In N. stephensi, the rates of α‐pinene metabolism increased with dietary juniper and were positively correlated with CYP2B concentration. The ability of N. stephensi to elevate CYP2B concentration and rate of α‐pinene metabolism with increasing levels of juniper in the diet may facilitate juniper specialization in this species.     

Differential expression and activity of catechol-O-methyl transferase (COMT) in a generalist (Neotoma albigula) and juniper specialist (Neotoma stephensi) woodrat

Mammalian herbivores, particularly dietary specialists must have an efficient means to metabolize the high doses of plant secondary compounds they consume. We found previously that Neotoma stephensi, a juniper specialist, upregulated catechol-O-methyl transferase (COMT) mRNA almost seven fold in response to an ecologically relevant diet (70% juniper). To further investigate the relevance of this enzyme with respect to juniper metabolism, we compared the protein expression, activity and kinetics of the two forms of COMT, soluble (S-COMT) and membrane bound (MB-COMT), in the blood, kidneys and liver of N. stephensi on its natural juniper diet to that of N. stephensi fed an experimental diet of 70% juniper as well as a non-toxic control diet under laboratory conditions. In addition, we compared these results to that of Neotoma albigula, a generalist species, which consumes a diet of 25% juniper in the wild. The specialist consuming juniper under both field and laboratory conditions had increased S-COMT expression and activity in their livers and kidneys, and increased S-COMT activity in their blood compared to the specialist and generalist fed the control diet. The specialist showed expression and activity of S-COMT in their kidneys that was as high as or higher than that in their livers. The generalist had an elevated V_max for MB-COMT compared to the specialist that resulted in higher activity for MB-COMT than the specialist despite lower expression of MB-COMT in the generalist's livers and kidneys. This high activity MB-COMT may be in part responsible for differences in the behaviors of the generalist compared to the specialist. We conclude that S-COMT is important in the specialist's ability to consume high levels of juniper.     

Three sympatric species of Neotoma: dietary specialization and coexistence

Summary Three sympatric species of Neotoma occur in the southern Great Basin Desert in northern Arizona. Observations and experiments from 1980–1984 focused on diet and den selection to determine to what extent woodrats partition available food and shelter. Analyses included microscopic inspection of feces from live-trapped animals, forage moisture content, and seasonal habitat utilization. Each species of woodrat was found to selectively forage on a different genus of the three evergreens on the study site: N. albigula was the only species to eat appreciable amounts of Yucca, while N. devia, specialized on Ephedra epidermis, and N. stephensi on Juniperus. Observations in the laboratory showed a linear dominance hierarchy where the larger species dominated smaller ones, i.e., N. albigula>N. stephensi>N. devia. To determine if such a hierarchy existed in the field, the behaviorally dominant species (N. albigula and N. stephensi) were continually removed (from a 25 ha experimental plot) over a 12-month period leaving only the subordinate species (N. devia) in the area. In these experiments, 40% of the dominant-species dens became occupied by 20 of the subordinate-species on the removal plot, whereas there were no interspecific den site (n=39) changes among species on the control plot. Removal of the two dominant Neotoma spp resulted in an increase of N. devia from a pre-removal high of 16 to a post-removal population of 26 individuals. These data suggest that while these woodrats may not compete for food, the subordinate species compete with the dominant species for den sites, prime dens being sequestered by the behaviorally dominant species.     

Woodrat (<Emphasis Type="Italic">Neotoma</Emphasis>) herbivores maintain nitrogen balance on a low-nitrogen,high-phenolic forage, <Emphasis Type="Italic">Juniperus monosperma</Emphasis>

The acquisition of adequate quantities of nitrogen is a challenge for herbivorous vertebrates because many plants are in low nitrogen and contain secondary metabolites that reduce nitrogen digestibility. To investigate whether herbivores maintain nitrogen balance on plant diets low in nitrogen and high in secondary compounds, we studied the effect of juniper (Juniperus monosperma) ingestion on the nitrogen balance of two species of herbivorous woodrats (Neotoma stephensi and N. albigula). These woodrat species feed on the foliage of juniper: N. stephensi is a juniper specialist, whereas N. albigula is a generalist that incorporates some juniper in its diet. Based on the nitrogen contents of the natural diets of these woodrats, we predicted that the generalist would be in negative nitrogen balance on a juniper diet whereas the specialist would not be affected. We found that both species of woodrat had low-nitrogen requirements (334.2 mg N/kg^0.75/day) and that a diet of 50% juniper did not result in negative nitrogen balance for either species. However, excretion patterns of nitrogen were altered; on the 50% juniper diet, fecal nitrogen losses increased ~38% and urinary nitrogen losses were half that of the control diet. The results suggest that absorption and detoxification of juniper secondary compounds may be more important for restricting juniper intake by the generalist than nitrogen imbalance.     

Adaptation to oak and other fibrous,phenolic-rich foliage by a small mammal,Neotoma fuscipes

Summary Neotoma fuscipes, a small mammalian herbivore with apparently generalized food habits, was laboratory tested to determine its degree of dietary specialization. Woodrats from both oak woodland and coastal sage communities preferred Quercus agrifolia leaves (containing 40% phenolics and about 16% condensed tannin) over foliage from other dominant species. Approximately one-third of the oak phenolics and less than 10% of the oak condensed tannin remained in the feces. Their performance on pure oak leaves was comparable to that on a mixed diet of Quercus, Salvia, Eriogonum, and Rhus, with respect to weight maintenance, digestive efficiency and total amount ingested. Digestive efficiency was low on the oak diet (55%) relative to Salvia (77%), and to achieve similar weight levels, approximately twice as much oak as Salvia was ingested. Woodrats retained more nitrogen as oak consumption increased. Intake of oak and other foods increased with each experimental day. A sympatric species, N. lepida, was unable to maintain weight on oak leaves, although its digestive and polyphenolic-degrading capabilities, and nitrogen retention efficiency were equivalent to those of N. fuscipes. On a weight-adjusted basis, N. lepida ate about half as much oak per day as N. fuscipes. Oak intake may have been reduced by an inability to rapidly degrade fiber, which constitutes about 30% of the oak diet. In natural populations, N. fuscipes selectively feeds on evergreen sclerophyll vegetation high in fiber, tannins and related polyphenolics. Individuals ingest 2–3 plant types at a time, with a single species (oak when available) constituting most of the material consumed. Neotoma lepida diets are also dominated by a single species. The diversity of plant types eaten by different populations of N. lepida suggests that local dietary specializations may be developmentally acquired.     

Plant Secondary Compounds as Diuretics: An Overlooked Consequence

Plant secondary compounds are deterrents and toxins to a varietyof herbivores. The effect of secondary compounds on water balanceof herbivores is virtually unexplored, yet many secondary compoundsare renowned for their diuretic effects in humans and laboratoryrats. We review data from the ethnopharmocological literatureon plants with diuretic effects. We also present our data fromexperiments on water intake of specialist (Neotoma stephensi)and generalist woodrats (N. albigula) consuming plant secondarycompounds from their natural diet. We measured effects of dietarysecondary compounds on voluntary water consumption, urine volumeand urine osmolarity. Ingestion of secondary compounds increasedwater intake and urine output and decreased urine osmolarityin both species. However, the generalist was more impacted bydietary secondary compounds than the specialist. Our resultscombined with that from the literature suggest that diuresismay be a prevalent consequence of ingestion of secondary compounds.Many herbivores live in arid habitats with limited access tofree-standing water, thus an increase in the desire for watermay have profound consequences on foraging behavior and fitness.     

Diet breadth of mammalian herbivores: nutrient versus detoxification constraints

Two hypotheses, nutrient constraints and detoxification limitation, have been proposed to explain the lack of specialists among mammalian herbivores. The nutrient constraint hypothesis proposes that dietary specialization in mammalian herbivores is rare because no one plant can provide all requisite nutrients. The detoxification limitation hypothesis suggests that the mammalian detoxification system is incapable of detoxifying high doses of similar secondary compounds present in a diet of a single plant species. We experimentally tested these hypotheses by comparing the performance of specialist and generalist woodrats (Neotoma) on a variety of dietary challenges. Neotoma stephensi is a narrow dietary specialist with a single species, one-seeded juniper, Juniperus monosperma, comprising 85–95% of its diet. Compared with other plants available in the habitat, juniper is low in nitrogen and high in fiber, phenolics, and monoterpenes. The generalist woodrat, N. albigula, also consumes one-seeded juniper, but to a lesser degree. The nutrient constraint hypothesis was examined by feeding both species of woodrats a low-nitrogen, high-fiber diet similar to that found in juniper. We found no differences in body mass change, or apparent digestibility of dry matter or nitrogen between the two species of woodrats after 35 days on this diet. Moreover, both species were in positive nitrogen balance. We tested the detoxification limitation hypothesis by comparing the performance of the generalist and specialist on diets with and without juniper leaves, the preferred foliage of the specialist, as well as on diets with and without α-pinene, the predominant monoterpene in juniper. We found that on the juniper diet, compared with the specialist, the generalist consumed less juniper and lost more mass. Urine pH, a general indicator of overall detoxification processes, declined in both groups on the juniper diet. The generalist consumed half the toxin load of the specialist yet its urine pH was slightly lower. Moreover, the generalist consumed significantly less of the treatment with high concentrations of α-pinene compared to the control treatment, while the specialist consumed the same amount of food regardless of α-pinene concentration. For both groups, urine pH declined as levels of α-pinene in the diet increased. The generalist produced a significantly more acidic urine than the specialist on the treatment with the highest α-pinene concentration. Our results suggest that in this system, specialists detoxify plant secondary compounds differently than generalists and plant secondary compounds may be more important than low nutrient levels in maintaining dietary diversity in generalist herbivores. Received: 5 May 1999 / Accepted: 14 November 1999     

The Gastrointestinal Tract of the White-Throated Woodrat (Neotoma albigula) Harbors Distinct Consortia of Oxalate-Degrading Bacteria

The microbiota inhabiting the mammalian gut is a functional organ that provides a number of services for the host. One factor that may regulate the composition and function of gut microbial communities is dietary toxins. Oxalate is a toxic plant secondary compound (PSC) produced in all major taxa of vascular plants and is consumed by a variety of animals. The mammalian herbivore Neotoma albigula is capable of consuming and degrading large quantities of dietary oxalate. We isolated and characterized oxalate-degrading bacteria from the gut contents of wild-caught animals and used high-throughput sequencing to determine the distribution of potential oxalate-degrading taxa along the gastrointestinal tract. Isolates spanned three genera: Lactobacillus, Clostridium, and Enterococcus. Over half of the isolates exhibited significant oxalate degradation in vitro, and all Lactobacillus isolates contained the oxc gene, one of the genes responsible for oxalate degradation. Although diverse potential oxalate-degrading genera were distributed throughout the gastrointestinal tract, they were most concentrated in the foregut, where dietary oxalate first enters the gastrointestinal tract. We hypothesize that unique environmental conditions present in each gut region provide diverse niches that select for particular functional taxa and communities.     

Differential hepatic gene expression of a dietary specialist (Neotoma stephensi) and generalist (Neotoma albigula) in response to juniper (Juniperus monosperma) ingestion

Dietary specialization is thought to be rare in mammalian herbivores because of limitations of their detoxification system in processing large doses of a single type of plant secondary compound (PSC). Therefore, in order to specialize on a single species of plant, mammalian herbivores must have a highly efficient detoxification system for the particular types of PSCs they ingest. Using microarray technology, we looked at the expression of hepatic genes of a dietary specialist, Neotoma stephensi, and a sympatric generalist, Neotoma albigula, in response to diets containing different levels of one-seeded juniper (Juniperus monosperma). We found large between species differences in gene expression, as well as large within species differences when specialists fed a low juniper diet (25% juniper) were compared to specialists fed their ecologically relevant level of juniper (70% juniper). We also tested the hypothesis that the specialist relies on less costly phase I detoxification enzymes more than phase II compared to the generalist. Although we found that the specialist had higher cumulative as well as average expression of phase I versus phase II enzymes, the generalist had a similar pattern of expression for phase I versus phase II enzymes.     

Molecular phylogenetics of an endangered species: the Tamaulipan woodrat (<Emphasis Type="Italic">Neotoma angustapalata</Emphasis>)

Neotoma angustapalata (Tamaulipan woodrat) is a large cricetid rodent found only in southwestern Tamaulipas and northeastern San Luis Potosí, Mexico. This species currently is listed as endangered due to habitat alteration, its restricted distribution, and relative rarity. Previous taxonomic assessments have allied N. angustapalata with N. albigula (now encompassing N. leucodon), N. mexicana or N. micropus. We sequenced portions of the mitochondrial cytochrome b gene from two skin samples of the Tamaulipan woodrat, including one of two topotypes. We estimated genealogical relationships between N. angustapalata and other species of Neotoma using maximum likelihood and Bayesian inference. In general, our results confirm the phylogeny of woodrats as proposed previously but we also recovered major genetic differentiation within what currently is recognized as N. mexicana and N. albigula. Our data document that the Tamaulipan woodrat is genetically indistinguishable from geographically adjacent haplotypes of N. leucodon. However, mitochondrial introgression from N. leucodon cannot be ruled out inasmuch as we were not able to obtain nuclear sequence data for N. angustapalata. Morphological analyses document that both male and female Tamaulipan woodrats differ morphologically from N. leucodon. Given that the Tamaulipan woodrat is diagnosable morphologically and occurs in habitat that differs from N. leucodon, we recognize N. angustapalata as a species-level entity.     

Selective fungal bioprecipitation of cobalt and nickel for multiple-product metal recovery

There are a need for novel, economical and efficient metal processing technologies to improve critical metal sustainability, particularly for cobalt and nickel which have extensive applications in low-carbon energy technologies. Fungal metal biorecovery processes show potential in this regard and the products of recovery are also industrially significant. Here we present a basis for selective biorecovery of Co and Ni oxalates and phosphates using reactive spent Aspergillus niger culture filtrate containing mycogenic oxalate and phosphate solubilized from struvite. Selective precipitation of oxalates was achieved by adjusting phosphate-laden filtrates to pH 2.5 prior to precipitation. Co recovery at pH 2.5 was high with a maximum of ~96% achieved, while ~60% Ni recovery was achieved, yielding microscale polyhedral biominerals. Co and Ni phosphates were precipitated at pH 7.5, following prior oxalate removal, resulting in near-total Co recovery (>99%), while Ni phosphate yields were also high with a recovery maximum of 83.0%.     

Status of the exotic ant <Emphasis Type="Italic">Nylanderia flavipes</Emphasis> (Hymenoptera: Formicidae) in northeastern Ohio

In 2005, the non-native Nylanderia flavipes was first recorded from Ohio. Here, we present the results of a baseline study designed to assess the status of this exotic species in northeastern Ohio and to explore its potential impacts on local ant communities and the extent to which it has been incorporated into the diet of a native predator, the red-backed salamander. At the sites where N. flavipes occurred, we found a sixfold increase in total ant abundance, with 87% of all ants collected being N. flavipes. The high numerical dominance of N. flavipes did not lead to observable changes in the species richness and abundance of the native ant community. At baits, N. flavipes did not engage in interspecific combat and did not exhibit aggression towards native ants. Thus, aggression and interference competition are not likely factors explaining the high local abundance of N. flavipes. Red-backed salamanders have incorporated N. flavipes into their diet, but further research is needed to understand the interactions of N. flavipes within the forest-floor food web. Although we did not detect changes in the local ant communities in the presence of N. flavipes, we argue that this species’ high local abundance and ability to forage at cooler temperatures may give it a competitive advantage and thereby affect native ants through exploitative competition.     

Monazite transformation into Ce- and La-containing oxalates by Aspergillus niger

Monazite is a naturally occurring lanthanide (Ln) phosphate mineral [Ln _x(PO₄) _y] and is the main industrial source of the rare earth elements (REE), cerium and lanthanum. Endeavours to ensure the security of supply of elements critical to modern technologies view bioprocessing as a promising alternative or adjunct to new methods of element recovery. However, relatively little is known about microbial interactions with REE. Fungi are important geoactive agents in the terrestrial environment and well known for properties of mineral transformations, particularly phosphate solubilization. Accordingly, this research examined the capability of a ubiquitous geoactive soil fungus, Aspergillus niger, to affect the mobility of REE in monazite and identify possible mechanisms for biorecovery. It was found that A. niger could grow in the presence of monazite and mediated the formation of secondary Ce and La-containing biominerals with distinct morphologies including thin sheets, orthorhombic tablets, acicular needles, and rosette aggregates which were identified as cerium oxalate decahydrate (Ce₂(C₂O₄)₃·10H₂O) and lanthanum oxalate decahydrate (La₂(C₂O₄)₃·10H₂O). In order to identify a means for biorecovery of REE via oxalate precipitation the bioleaching and bioprecipitation potential of biomass-free spent culture supernatants was investigated. Although such indirect bioleaching of REE was low from the monazite with maximal lanthanide release reaching >40 mg L⁻¹, leached REE were efficiently precipitated as Ce and La oxalates of high purity, and did not contain Nd, Pr and Ba, present in the original monazite. Geochemical modelling of the speciation of oxalates and phosphates in the reaction system confirmed that pure Ln oxalates can be formed under a wide range of chemical conditions. These findings provide fundamental knowledge about the interactions with and biotransformation of REE present in a natural mineral resource and indicate the potential of oxalate bioprecipitation as a means for efficient biorecovery of REE from solution.     

Intestinal capacity of P-glycoprotein is higher in the juniper specialist, Neotoma stephensi, than the sympatric generalist, Neotoma albigula

Permeability-glycoprotein (Pgp) is a membrane-bound, ATP-dependent, transport protein that excludes many cytotoxic compounds including plant metabolites and pollutants from the barrier epithelia of many tissues including the small intestine. We hypothesized that intestinal Pgp capacity would be higher in Neotoma stephensi, a specialist on Juniperus monosperma known to be high in plant toxins, than the sympatric generalist, Neotoma albigula, which consumes juniper in the field, but is unable to tolerate a high juniper diet. We measured Pgp activity as the difference in accumulation of a known Pgp substrate, digoxin, between everted sections of small intestine exposed to ethanol vehicle control and a maximal level of a known competitive inhibitor of Pgp, cyclosporin A. We estimated intestinal capacity by averaging Pgp activity along the intestine and multiplying by total small intestine mass. These first measures of Pgp in wild mammals show a significant difference among species with the juniper specialist, N. stephensi, exhibiting a 2.4 fold higher capacity than the generalist, N. albigula. This result suggests that Pgp may play a role in the ability of N. stephensi to tolerate juniper.     

Colonization,penetration and transformation of manganese oxide nodules by Aspergillus niger

In this study, the ability of the geoactive fungus Aspergillus niger to colonize and transform manganese nodules from the Clarion-Clipperton Zone in both solid and liquid media was investigated. Aspergillus niger was able to colonize and penetrate manganese nodules embedded in solid medium and effect extensive transformation of the mineral in both fragmented and powder forms, precipitating manganese and calcium oxalates. Transformation of manganese nodule powder also occurred in a liquid medium in which A. niger was able to remove the fine particles from suspension which were accumulated within the central region of the resulting mycelial pellets and transformed into manganese oxalate dihydrate (lindbergite) and calcium oxalate dihydrate (weddellite). These findings contribute to an understanding of environmental processes involving insoluble manganese oxides, with practical relevance to chemoorganotrophic mineral bioprocessing applications, and, to the best of our knowledge, represent the first demonstration of fundamental direct and indirect interactions between geoactive fungi and manganese nodules.     

Effects of consumption of juniper (Juniperus monosperma) on cost of thermoregulation in the woodrats Neotoma albigula and Neotoma stephensi at different acclimation temperatures

A study was done to test whether toxic plants that occur naturally in the diet affect thermoregulation in mammalian herbivores. The woodrats Neotoma albigula and Neotoma stephensi both consume juniper (Juniperus monosperma), a plant with high levels of toxic compounds. Body temperature (Tb), basal metabolic rate (BMR), and the minimum cost of thermogenesis (Cmin) were measured for both species on control and juniper diets following warm (25 degrees C) and cold (18 degrees C) acclimation. In N. albigula, diet had no uniform effect on Tb, BMR, or Cmin, but dietxacclimation-temperature interaction effects on Tb and Cmin were highly significant (P<0.005). For thermoregulation at 15 degrees C, juniper consumption increased the metabolic cost for warm-acclimated N. albigula by 50% but decreased the metabolic cost in cold-acclimated N. albigula by 24%. In N. stephensi, diet significantly affected Tb and Cmin (P<0.05), but there were no significant dietxacclimation-temperature interaction effects. For thermoregulation at 15 degrees C, juniper consumption increased the metabolic cost for warm-acclimated N. stephensi by 33% but had no significant effect on metabolic cost in cold-acclimated N. stephensi.     

Effects of Chemical Speciation on the Mineralization of Organic Compounds by Microorganisms

The mineralization of 1.0 to 100 ng each of four complexing compounds—oxalate, citrate, nitrilotriacetate (NTA), and EDTA—per ml was tested in media prepared in accordance with equilibrium calculations by a computer program so that the H, Ca, Mg, Fe, or Al complex (chemical species) was predominant. Sewage microorganisms mineralized calcium citrate more rapidly than iron, aluminum, or hydrogen citrate, and magnesium citrate was degraded slowest. Aluminum, hydrogen, and iron oxalates were mineralized more rapidly than calcium oxalate, and magnesium oxalate was decomposed slowest. Sewage microorganisms mineralized calcium NTA but not aluminum, magnesium, hydrogen, or iron NTA or any of the EDTA complexes. Pseudomonas sp. mineralized calcium and iron citrates but had no activity on hydrogen, aluminum, or magnesium citrate. Pseudomonas pseudoalcaligenes mineralized calcium, iron, hydrogen, and aluminum citrates but had little activity on magnesium citrate. Pseudomonas alcaligenes used calcium, iron, hydrogen, and aluminum oxalates readily, but it used magnesium oxalate at a slower rate. Listeria sp. destroyed calcium NTA but had no effect on hydrogen, iron, or magnesium NTA. Increasing the Ca concentration in the medium enhanced the breakdown of NTA by Listeria sp. The different activities of the bacterial isolates were not a result of the toxicity of the complexes or the lack of availability of a nutrient element. NTA mineralization was not enhanced by the addition of Ca to Beebe Lake water, but it was enhanced when Ca and an NTA-degrading inoculum were added to water from an oligotrophic lake. The data show that chemical speciation influences the mineralization of organic compounds by naturally occurring microbial communities and by individual bacterial populations.     

Eimeria ladronensis n. sp. and E. albigulae (Apicomplexa: Eimeriidae) from the Woodrat,Neotoma albigula (Rodentia: Cricetidae)1

Of 50 white-throated woodrats (Neotoma albigula) collected from Socorro Co., New Mexico, 21 (42%) had eimerian oocysts in their feces when examined. Of the 21 Neotoma found positive for Eimeria, 19 (90%) harbored a single eimerian species at time of examination. Eimeria albigulae Levine, Ivens & Kruidenier, 1957, was found in 18 (86%), and E. ladronensis n. sp. was found in five (24%) infected woodrats. Sporulated oocysts of E. ladronensis are ellipsoidal, 19–25 × 13–15 (21.4 ± 1.3 × 14.1 ± 1.1) μm, have a smooth wall and one or two polar granules, but lack a micropyle and an oocyst residuum. Sporocysts are tapered at one end, 7–10 × 6–7 (8.5 ± 0.7 × 6.5 ± 0.3) μm, and have a Stieda body and sporocyst residuum, but no substieda body. Prepatent periods for E. albigulae and E. ladronensis n. sp. are 5–6 and 8–9 days, respectively; patent periods are 7–18 and approximately 11 days, respectively.     

Biological control of nematodes: Soil amendments and microbial antagonists

Summary Organic matter amendments to soil can be used to manage phytoparasitic nematodes. The most effective amendments are those with narrow C:N ratios and high protein or amine-type N content. For soil with 1.0% (w/w) organic matter amendment there is a direct relation between extent of nematode control and the N content of amendments. A special group of amendments are those containing chitinous materials. Chitin addition to soil results in stimulation of a select microflora capable of degrading the polymer. Several microbial species are known to destroy the eggs of phytonematodes (Meloidogyne spp). Organic matter can be modified by addition of specific compounds or by inoculation with particular microbial species to produce an amendment that will induce suppressiveness.