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1.
Surg Obes Relat Dis ; 10(1): 121-4, 2014.
Article in English | MEDLINE | ID: mdl-24054470

ABSTRACT

BACKGROUND: The medicolegal aspects of bariatric surgery are very difficult to analyze scientifically because there is no central, searchable database of closed case claims and little incentive for malpractice insurers to divulge data. Examining medicolegal data may provide insight into the financial and psychological burden on physicians. Detailed data also may be used to improve patient safety and determine common causes of negligence. METHODS: All U.S.-based members of the American Society of Metabolic and Bariatric Surgeons were asked to complete a survey regarding their bariatric-related medical malpractice experience. RESULTS: Of the 1672 eligible members that received the survey, 330 responded (19.7%). Mean years in practice was 15.3 ± 9. Mean annual cost of malpractice insurance was $59,200 ± $52,000 (N = 197). The respondent surgeons experienced 1.5 ± 3.2 lawsuits on average over the course of their practice. Of the 330 respondents, 144 (48%) did not report a bariatric-related lawsuit filed against them. Of the 464 lawsuits reported by 156 surgeons, 126 were settled out of court (27%), 249 were dropped (54%), and 54 (18%) went to trial. Seventy-two percent of cases that went to trial were found to be in favor of the defense. The mean lifetime amount paid for suits was $250,000±$660,000. The probability of a bariatric surgeon experiencing a lawsuit was independently associated with the years in practice (P = .03) and number of total cases the surgeon has performed (P = .01). The annual cost of malpractice insurance was independently predicted by the amount paid in previous claims (P = .01). CONCLUSIONS: The probability of a medical malpractice lawsuit correlates positively to the number of procedures performed and the number of years the surgeon has been in practice.


Subject(s)
Bariatric Medicine/legislation & jurisprudence , Bariatric Surgery/legislation & jurisprudence , Malpractice/legislation & jurisprudence , Attitude of Health Personnel , Bariatric Medicine/economics , Bariatric Medicine/statistics & numerical data , Bariatric Surgery/economics , Bariatric Surgery/statistics & numerical data , Humans , Insurance, Liability/statistics & numerical data , Liability, Legal/economics , Malpractice/statistics & numerical data , Patient Safety , Surveys and Questionnaires , United States
2.
J Invertebr Pathol ; 111(2): 186-8, 2012 Oct.
Article in English | MEDLINE | ID: mdl-22841944

ABSTRACT

Eugregarines are abundant in a great diversity of invertebrates, and yet their relationships with their hosts are subject to controversy and confusion. We tested the effect of the eugregarine, Pyxinia crystalligera, on growth, development, and susceptibility to two Apicomplexa pathogens of the hide beetle, D. maculatus. Heavy infection with eugregarines provided partial protection from two pathogenic members of Apicomplexa, M. trogodermae and A. tribolii. Infection with P. crystalligera caused lower weight in beetle larvae, but did not significantly retard pupation or adult emergence. A. tribolii infection of Lepidoptera and M. trogodermae infection of D. maculatus are reported for the first time.


Subject(s)
Apicomplexa/physiology , Coleoptera/physiology , Disease Resistance , Animals , Coleoptera/immunology , Coleoptera/parasitology , Host-Parasite Interactions , Larva/growth & development , Larva/immunology , Larva/parasitology
3.
J Eukaryot Microbiol ; 59(3): 246-50, 2012.
Article in English | MEDLINE | ID: mdl-22510059

ABSTRACT

The yellow mealworm, Tenebrio molitor, harbors a symbiont that has spores with a thick, laminated wall and infects the fat body and ventral nerve chord of adult and larval beetles. In adult males, there is heavy infection of the epithelial cells of the testes and between testes lobes with occasional penetration of the lobes. Spores are enveloped in the spermatophores when they are formed at the time of mating and transferred to the female's bursa copulatrix. Infection has not been found in the ovaries. The sequence of the nuclear small subunit rDNA indicates that the symbiont is a member of the Ichthyosporea, a class of protists near the animal-fungi divergence.


Subject(s)
Mesomycetozoea/physiology , Reproduction/physiology , Symbiosis , Tenebrio/parasitology , Animals , DNA, Protozoan/analysis , Female , Male , Mesomycetozoea/genetics , Mesomycetozoea/ultrastructure , Phylogeny , Sequence Analysis, DNA , Spermatogonia , Spores, Protozoan/ultrastructure , Tenebrio/physiology , Testis/parasitology
4.
J Invertebr Pathol ; 109(2): 260-3, 2012 Feb.
Article in English | MEDLINE | ID: mdl-22200644

ABSTRACT

The spotted asparagus beetle, Crioceris quatuordecimpunctata (Coleoptera: Chrysomelidae), is one of the most devastating pests of asparagus in China. Sprayed synthetic pesticides have been used to control C. quatuordecimpunctata damage, but they pose problems because of residues and harm to natural enemies. Neither the microbial coleopteran-specific toxin from Bacillus thuringiensistenebrionis, Cry3Aa, nor the fungal pathogen Beauveria bassiana have sufficient activity to effectively control C. quatuordecimpunctata damage to asparagus. However, second instar C. quatuordecimpunctata larvae exposed to a sublethal dose of Cry3Aa toxin demonstrated significantly higher larval mortality when exposed to B. bassiana. Our results suggest that a combination of Cry3Aa and B. bassiana may be effective in reducing damage by C. quatuordecimpunctata larvae to asparagus.


Subject(s)
Beauveria/physiology , Coleoptera , Insecticides , Microsporidiosis/veterinary , Animals , Asparagus Plant/parasitology , Bacillus thuringiensis/drug effects , Bacillus thuringiensis/genetics , Bacillus thuringiensis/metabolism , Bacillus thuringiensis Toxins , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Bacterial Proteins/pharmacology , Beauveria/drug effects , Beauveria/pathogenicity , Biological Assay , Disease Susceptibility , Endotoxins/genetics , Endotoxins/metabolism , Endotoxins/pharmacology , Hemolysin Proteins/genetics , Hemolysin Proteins/metabolism , Hemolysin Proteins/pharmacology , Larva/drug effects , Larva/microbiology , Lethal Dose 50 , Microsporidiosis/drug therapy , Pest Control, Biological/methods
5.
J Econ Entomol ; 103(5): 1542-6, 2010 Oct.
Article in English | MEDLINE | ID: mdl-21061951

ABSTRACT

Sanitation being an important component of chemical-free management of stored-products pests, the nutritional stress on insects that results from a clean environment may prove advantageous to the use of microbial controls. Dietary stress by food deprivation or suboptimal diet increased susceptibility of the red flour beetle, Tribolium castaneum (Herbst), larvae to Beauveria bassiana (Balsamo) Vuillemin. Fungus-related mortality increased linearly with the number of days of food deprivation. Rearing of larvae on a rice meal diet resulted in slower development and greater susceptibility to B. bassiana than rearing on whole wheat flour with brewer's yeast. Larvae that were fed for 24 h on flour with B. bassiana conidia consumed significantly less and weighed significantly less than those that were fed fungus-free flour. Thus, the presence of B. bassiana conidia is itself a cause of dietary stress.


Subject(s)
Beauveria/physiology , Pest Control, Biological/methods , Tribolium/growth & development , Tribolium/microbiology , Animal Feed , Animals , Food Deprivation , Larva/microbiology
6.
Fungal Biol ; 114(2-3): 151-9, 2010.
Article in English | MEDLINE | ID: mdl-20960971

ABSTRACT

Sequences of peptidases with conserved motifs around the active site residues that are characteristic of trypsins (similar to trypsin peptidases, STP) were obtained from publicly-available fungal genomes and related databases. Among the 75 fungal genomes, 29 species of parasitic Ascomycota contained genes encoding STP and their homologs. Searches of non-redundant protein sequences, patented protein sequences, and expressed sequence tags resulted in another 18 STP sequences in 10 fungal species from Ascomycota, Basidiomycota, and Zygomycota. A comparison of fungi species containing STP sequences revealed that almost all are pathogens of plants, animals or fungi. A comparison of the primary structure of homologous proteins, including the residues responsible for substrate binding and specificity of the enzyme, revealed three groups of homologous sequences, all presumably from S1 family: trypsin-like peptidases, chymotrypsin-like peptidases and serine peptidases with unknown substrate specificity. Homologs that are presumably functionally inactive were predicted in all groups. The results in general support the hypothesis that the expression of trypsin-like peptidases in fungi represents a marker of fungal phytopathogenicity. A phylogenetic tree was constructed using peptidase and homolog amino acid sequences, demonstrating that all have noticeable differences and almost immediately deviate from the common root. Therefore, we conclude that the changes that occurred in STP of pathogenic fungi in the course of evolution represent specific adaptations to proteins of their respective hosts, and mutations in peptidase genes are important components of life-style changes and taxonomic divergence.


Subject(s)
Fungal Proteins/genetics , Fungi/enzymology , Fungi/pathogenicity , Mycoses/microbiology , Plant Diseases/microbiology , Trypsin/genetics , Amino Acid Motifs , Animals , Ascomycota/classification , Ascomycota/enzymology , Ascomycota/genetics , Ascomycota/pathogenicity , Basidiomycota/classification , Basidiomycota/enzymology , Basidiomycota/genetics , Basidiomycota/pathogenicity , Computational Biology/methods , Fungal Proteins/metabolism , Fungi/classification , Fungi/genetics , Genome, Fungal/genetics , Humans , Peptide Hydrolases/genetics , Peptide Hydrolases/metabolism , Phylogeny , Sequence Alignment , Serine Endopeptidases/genetics , Serine Endopeptidases/metabolism , Substrate Specificity , Trypsin/metabolism
7.
J Agric Food Chem ; 58(16): 8948-51, 2010 Aug 25.
Article in English | MEDLINE | ID: mdl-20672839

ABSTRACT

The genome of the genetic model for coleopteran insects, Tribolium castaneum, is now available for downstream applications. To facilitate gene expression studies in T. castaneum, genes were evaluated for suitability as normalizers in comparisons across tissues and/or developmental stages. In less diverse samples, such as comparisons within developmental stages or tissue only, normalizers for mRNA were more stable and consistent. Overall, the genes for ribosomal proteins rps6, rpl13a, rps3, and rps18 were the most stable normalizers for broad scale gene expression analysis in T. castaneum. However, their stability ranking was dependent upon the instrument as well as the analysis program. These data emphasize the need to optimize normalizers used in all real-time polymerase chain reaction experiments specifically for the experimental conditions and thermocycler and to carefully evaluate data generated by computational algorithms.


Subject(s)
Genes, Insect , Polymerase Chain Reaction/methods , Tribolium/genetics , Animals , Base Sequence , DNA Primers , Life Cycle Stages , Tribolium/physiology
8.
J Invertebr Pathol ; 105(1): 112-5, 2010 Sep.
Article in English | MEDLINE | ID: mdl-20460127

ABSTRACT

A microsporidium that closely resembles Paranosema species at the level of the light microscope was isolated from the rusty grain beetle, Cryptolestes ferrugineus. It's identity as Nosema oryzaephili (originally described from Oryzaephilus surinamensis) was confirmed by comparison with a known isolate of N. oryzaephili based on spore size, small subunit rDNA sequence, and relative infectivity to O. surinamensis, Tribolium castaneum, and Ephestia kuehniella. Phylogenetic analysis of the small subunit rDNA indicates clearly that this species belongs in the genus Paranosema and thus the designation Paranosema oryzaephili (Burges, Canning and Hurst) is proposed. In spite of the abundance, economic importance, and world-wide distribution of C. ferrugineus, this is the first report of a microsporidial infection in this species. This is also the first report of P. oryzaephili in the new world.


Subject(s)
Coleoptera/microbiology , Nosema/genetics , Nosema/isolation & purification , Phylogeny , Animals , DNA, Fungal/genetics , DNA, Ribosomal/genetics , Microsporidia, Unclassified/isolation & purification , Microsporidia, Unclassified/pathogenicity , Microsporidiosis/microbiology , Nosema/pathogenicity
9.
J Microbiol Methods ; 80(2): 219-21, 2010 Feb.
Article in English | MEDLINE | ID: mdl-20026205

ABSTRACT

To investigate gene expression in Tribolium castaneum exposed to Beauveria bassiana, reference genes for qPCR were evaluated. Of these, beta-actin, alpha-tubulin, and RPS6 were not stable. The most stable were ribosomal protein genes, RPS3, RPS18, and RPL13a. Syntaxin1, syntaxin6, and E-cadherin may be appropriate for some experimental systems.


Subject(s)
Beauveria/immunology , Beauveria/pathogenicity , Gene Expression Profiling/methods , Polymerase Chain Reaction/methods , Polymerase Chain Reaction/standards , Reference Standards , Tribolium/genetics , Animals , Tribolium/microbiology
10.
Obes Surg ; 19(8): 1190-4, 2009 Aug.
Article in English | MEDLINE | ID: mdl-19506984

ABSTRACT

BACKGROUND: Atypical complications of gastric bypass surgery include the Roux-en-O configuration: an improper connection of the bilio-pancreatic limb to the gastric pouch. METHODS: Four cases of Roux-en-O, which occurred at institutions not affiliated with the authors, were reviewed for issues related to causation and patient outcomes. RESULTS: One case was diagnosed intraoperatively (patient 1), while the time of diagnosis in the remaining three patients was postoperative days 2, 52, and 230 (patients 2-4). The delay resulted in two computed tomography scans, two endoscopies, and four contrast studies per patient. These patients presented with protracted biliary emesis and a clinical picture of bowel obstruction. Irrespective of time to diagnosis, all patients endured significant postoperative sequelae-numerous surgeries (n=10, 3, 1, and 3, respectively) and increased length of stay (97, 86, 49, and 125 days, respectively). Patients 2 and 3 were diagnosed by repeat laparotomy, and patient 4 was diagnosed by HIDA scan. CONCLUSIONS: Nevertheless, surgery remains the most effective means by which to diagnose the problem, as well as correct the complication. Maneuvers that should be employed to prevent this rare complication include keeping the bilio-pancreatic limb short, identifying the ligament of Treitz and marking the Roux limb shortly after jejunal transection.


Subject(s)
Gastric Bypass/adverse effects , Gastrointestinal Diseases/diagnosis , Gastrointestinal Diseases/etiology , Medical Errors/adverse effects , Vomiting/diagnosis , Vomiting/etiology , Adult , Contrast Media , Diagnosis, Differential , Female , Humans , Length of Stay , Male , Middle Aged , Tomography, X-Ray Computed , Young Adult
11.
Insect Biochem Mol Biol ; 38(4): 380-6, 2008 Apr.
Article in English | MEDLINE | ID: mdl-18342244

ABSTRACT

The whole genome sequence of Tribolium castaneum, a worldwide coleopteran pest of stored products, has recently been determined. In order to facilitate accurate annotation and detailed functional analysis of this genome, we have compiled and analyzed all available expressed sequence tag (EST) data. The raw data consist of 61,228 ESTs, including 10,704 obtained from NCBI and an additional 50,524 derived from 32,544 clones generated in our laboratories. These sequences were amassed from cDNA libraries representing six different tissues or stages, namely: whole embryos, whole larvae, larval hindguts and Malpighian tubules, larval fat bodies and carcasses, adult ovaries, and adult heads. Assembly of the 61,228 sequences collapsed into 12,269 clusters (groups of overlapping ESTs representing single genes), of which 10,134 mapped onto 6,463 (39%) of the 16,422 GLEAN gene models (i.e. official Tribolium gene list). Approximately 1,600 clusters (13% of the total) lack corresponding GLEAN models, despite high matches to the genome, suggesting that a considerable number of transcribed sequences were missed by the gene prediction programs or were removed by GLEAN. We conservatively estimate that the current EST set represents more than 7,500 transcription units.


Subject(s)
Expressed Sequence Tags , Gene Expression Profiling , Tribolium/genetics , Animals , Databases, Nucleic Acid , Gene Library , Tribolium/metabolism
12.
Surg Obes Relat Dis ; 4(1): 11-3, 2008.
Article in English | MEDLINE | ID: mdl-18065292

ABSTRACT

BACKGROUND: Both obesity and surgery are known risk factors for instigating gouty attacks. We describe the incidence and management of postoperative gouty attacks after bariatric surgery. METHODS: We performed a retrospective, multi-institutional review of 411 consecutive laparoscopic gastric bypass patients and identified all patients with postoperative gouty attacks. RESULTS: Of the 411 patients reviewed, 21 (5.1%) had had a previous diagnosis of gout. Of these 21 patients, 7 (33.3%) had had an acute attack postoperatively. No patient who had never had a preoperative episode developed gout. In 4 of the 7 (57.1%) patients, the attack was severe enough to require treatment with corticosteroids. Monoarticular attacks occurred in 5 (71.4%) of the 7 patients, and polyarticular attacks occurred in 2 (28.6%). The joints involved included the toes, ankles, and wrists. One patient presented with cervical gout and developed polyarticular gout that required a significant rehabilitation stay. CONCLUSION: The morbidity of postoperative gouty attacks in bariatric surgery patients is significant. Patients with a history of gout should given prophylactic treatment and closely monitored.


Subject(s)
Gastric Bypass , Gout/epidemiology , Obesity/surgery , Postoperative Complications , Adult , Aged , Body Mass Index , Female , Humans , Incidence , Male , Middle Aged , Obesity/complications , Retrospective Studies , Risk Factors
13.
J Econ Entomol ; 100(4): 1071-4, 2007 Aug.
Article in English | MEDLINE | ID: mdl-17849853

ABSTRACT

Red flour beetle, Tribolium castaneum (Herbst), is a major pest of stored and processed grains that is tolerant of Beauveria bassiana (Balsamo) Vuillemin under most conditions. Laboratory assays demonstrated that desiccating conditions improved the efficacy of the fungus. For T. castaneum larvae exposed to B. bassiana at different vapor pressure deficits (VPDs), the LC50 potency ratios were 2.3 for 2.42 kPa and 3.9 for 3.31 kPa compared with 1.06 kPa. There were significant effects of moisture on B. bassiana-associated mortality even with brief exposure to low VPD before or at the beginning of exposure to fungus. When T. castaneum larvae were held at 3.31 kPa 1 d before exposure to B. bassiana and/or in the first 1 or 2 d of exposure to the fungus, there was significantly greater mortality for all of the low moisture treatments than occurred with continuous incubation at 1.06 kPa. B. bassiana efficacy for adult T. castaneum was significantly better for VPDs of 3.56 or 3.78 than 1.06 kPa. Weight gain over 4 d of incubation with moisture held constant was significantly less at a VDP of 3.31 kPa than at 1.87 or 1.06 kPa. Treatment with fungus did not affect weight gain significantly. There was no significant difference in larval water content among treatments.


Subject(s)
Beauveria/physiology , Pest Control, Biological/methods , Tribolium/microbiology , Animals , Body Weight , Desiccation , Larva/growth & development , Larva/metabolism , Larva/microbiology , Mortality , Tribolium/growth & development , Tribolium/metabolism , Water/metabolism
14.
Surg Obes Relat Dis ; 3(1): 60-6; discussion 66-7, 2007.
Article in English | MEDLINE | ID: mdl-17196438

ABSTRACT

BACKGROUND: Very few studies have addressed malpractice litigation specific to bariatric surgery. This study was designed to analyze litigation trends in bariatric surgery to prevent further lawsuits and improve patient care. METHODS: A total of 100 consecutive bariatric lawsuits were reviewed by a consortium of experienced bariatric surgeons and an attorney specializing in medical malpractice. RESULTS: Of the 100 lawsuits, 45% were reviewed for defense attorneys. The mean patient age was 40 years (range 18-65), 75% were women, 81% had a body mass index of <60, 31% were diabetic, and 38% had sleep apnea. Of the surgeons, 42% had <1 year of experience, and 26% had done <100 cases. Although 69% of the physicians were members of the American Society of Bariatric Surgery, only 22% had detailed consent forms. The surgical procedures were performed between 1997 and 2005 and included Roux-en-Y gastric bypass (78% total, 33% open, and 45% laparoscopic), vertical banded gastroplasty (3%), minigastric bypass (6%), biliopancreatic diversion/duodenal switch (4%), and revision (9%). Of the 100 cases, 32% involved an intraoperative complication and 72% required additional surgery. The most common adverse events initiating litigation were leaks (53%), intra-abdominal abscess (33%), bowel obstruction (18%), major airway events (10%), organ injury (10%), and pulmonary embolism (8%). From these injuries, 53 patients died, 28% had a full recovery, 12% had a minor disability, and 7% had major disabilities. Evidence of potential negligence was found in 28% of cases. Of these cases, 82% resulted from a delay in diagnosis and 64% from misinterpreted vital signs. CONCLUSIONS: This study found that leaks and delayed diagnosis were the most common cause of litigation. Even experienced bariatric surgeons should understand the most common errors made by others to prevent complications and avoid litigation.


Subject(s)
Bariatric Surgery/adverse effects , Bariatric Surgery/legislation & jurisprudence , Malpractice/legislation & jurisprudence , Adolescent , Adult , Aged , Female , Humans , Male , Middle Aged
16.
J Invertebr Pathol ; 94(1): 74-6, 2007 Jan.
Article in English | MEDLINE | ID: mdl-16996535

ABSTRACT

An indirect sandwich enzyme-linked immunosorbent assay (ELISA) for the detection of the neogregarine Mattesia oryzaephili was developed with monoclonal antibodies. It was used to screen laboratory colonies of Oryzaephilus surinamensis, Cryptolestes ferrugineus, C. pusillus, and C. turcicus from the United States, Canada, and Australia. All of the colonies except C. turcicus had larvae that tested positive with the percent of positives ranging from 0.2 to 83.9, but only colonies that tested positive had reported population declines. This assay will make possible epizootiological studies to assess the impact of M. oryzaephili on pest populations.


Subject(s)
Apicomplexa/isolation & purification , Coleoptera/parasitology , Enzyme-Linked Immunosorbent Assay/methods , Animals , Larva/parasitology
17.
J Invertebr Pathol ; 89(1): 19-29, 2005 May.
Article in English | MEDLINE | ID: mdl-16039302

ABSTRACT

In 125 years since Metchnikoff proposed the use of Metarhizium anisopliae to control the wheat cockchafer and brought about the first field trials, microbial control has progressed from the application of naturalists' observations to biotechnology and precision delivery. This review highlights major milestones in its evolution and presents a perspective on its current direction. Fungal pathogens, the most eye-catching agents, dominated the early period, but major mycological control efforts for chinch bugs and citrus pests in the US had questionable success, and interest waned. The discoveries of Bacillus popilliae and Bacillus thuringiensis began the era of practical and commercially viable microbial control. A program to control the Japanese beetle in the US led to the discovery of both B. popilliae and Steinernema glaseri, the first nematode used as a microbial control agent. Viral insect control became practical in the latter half of the 20th century, and the first registration was obtained with the Heliothis nuclear polyhedrosis virus in 1975. Now strategies are shifting for microbial control. While Bt transgenic crops are now planted on millions of hectares, the successes of more narrowly defined microbial control are mainly in small niches. Commercial enthusiasm for traditional microbial control agents has been unsteady in recent years. The prospects of microbial insecticide use on vast areas of major crops are now viewed more realistically. Regulatory constraints, activist resistance, benign and efficacious chemicals, and limited research funding all drive changes in focus. Emphasis is shifting to monitoring, conservation, integration with chemical pesticides, and selection of favorable venues such as organic agriculture and countries that have low costs, mild regulatory climates, modest chemical inputs, and small scale farming.


Subject(s)
Pest Control, Biological/history , Animals , Biotechnology/history , Europe , History, 19th Century , History, 20th Century , Industry/history , United States
18.
J Econ Entomol ; 98(3): 683-8, 2005 Jun.
Article in English | MEDLINE | ID: mdl-16022293

ABSTRACT

The carriers mineral oil and Silwet L-77 and the botanical insecticides Neemix 4.5 and Hexacide were evaluated for their impacts on the efficacy of Beauveria bassiana (Balsamo) Vuillemin conidia against red flour beetle, Tribolium castaneum (Herbst), larvae. The dosages of liquid treatments were quantified by both conidia concentration in the spray volume and conidia deposition on the target surface. The latter approach allowed comparison with dry, unformulated conidia. The median lethal concentrations of B. bassiana in 0.05% Silwet L-77 solution or without a carrier were approximately double that for conidia in mineral oil. Carriers had highly significant effects on the efficacy of B. bassiana. The lower efficacy of conidia in aqueous Silwet L-77 may have been the result of conidia loss from the larval surface because of the siloxane's spreading properties. Neemix 4.5 (4.5% azadirachtin) delayed pupation and did not reduce the germination rate of B. bassiana conidia, but it significantly reduced T. castaneum mortality at two of four tested fungus doses. Hexacide (5% rosemary oil) caused significant mortality when applied without B. bassiana, but it did not affect pupation, the germination rate of conidia, or T. castaneum mortality when used in combination with the fungus.


Subject(s)
Hypocreales/physiology , Insecticides/administration & dosage , Mineral Oil/administration & dosage , Pest Control, Biological , Plant Oils/administration & dosage , Tribolium , Animals , Oils, Volatile/administration & dosage
19.
J Econ Entomol ; 97(5): 1765-71, 2004 Oct.
Article in English | MEDLINE | ID: mdl-15568371

ABSTRACT

We tested the hypothesis that the entomopathogenic fungus Beauveria bassiana would be more efficacious on oat cultivars that prolonged the immature developmental period of sawtoothed grain beetle, Oryzaephilus surinamensis (L.), a storage pest. However, percentage of reduction in progeny production was similar on whole 'Don' and 'Paul' oats treated with fungus, even though immature developmental time was longer on whole 'Don' than on 'Paul' oats. In our initial test at 10 mg of conidia per kilogram of oats, the number of beetle progeny produced was reduced by 38-67% in whole oats, and there was no effect of the fungus on insects developing on cracked oats. Therefore, we conducted two dose-response studies that showed that adding 150 mg of conidia per kilogram to cracked or whole 'Paul' oats resulted in a 70 and 98% reduction, respectively, in number of progeny produced. No further reduction was obtained by adding 200 mg of conidia per kilogram of cracked or whole 'Paul' oats. Presence of the fungus did not affect developmental time in any of our tests. A previous study showed that cleaned oats should limit insect population growth to allow long-term storage of oats without insect damage. However, the current study shows that if the oats are not cleaned, and not cleaning oats is the normal storage practice, then B. bassiana could be used to help control sawtoothed grain beetles.


Subject(s)
Ascomycota/physiology , Avena/genetics , Avena/parasitology , Coleoptera/physiology , Pest Control, Biological/methods , Animals , Population Dynamics , Seeds/genetics , Seeds/parasitology , Time Factors
20.
Mycopathologia ; 158(2): 211-7, 2004 Aug.
Article in English | MEDLINE | ID: mdl-15518350

ABSTRACT

Maximum challenge exposure of Liposcelis bostrychophila to Beauveria bassiana, Paecilomyces fumosoroseus, Aspergillus parasiticus or Metarhizium anisopliae resulted in no more than 16% mortality. We investigated several of L. bostrychophila's cuticular lipids for possible contributions to its tolerance for entomopathogenic fungi. Saturated C14 and C16 fatty acids did not reduce the germination rates of B. bassiana or M. anisopliae conidia. Saturated C6 to C12 fatty acids that have not been identified in L. bostrychophila cuticular extracts significantly reduced germination, but the reduction was mitigated by the presence of stearamide. Cis-6-hexadecenal did not affect germination rates. Mycelial growth of either fungal species did not occur in the presence of caprylic acid, was reduced by the presence of lauric acid, and was not significantly affected by palmitic acid. Liposcelis bostrychophila is the only insect for which fatty acid amides have been identified as cuticular components. Stearamide, its major fatty amide, did not reduce germination of B. bassiana or M. anisopliae conidia or growth of their mycelia. Adhesion of conidia to stearamide preparations did not differ significantly from adhesion to the cuticle of L. bostrychophila. Pretreatment of a beetle known to be fungus-susceptible, larval Oryzaephilus surinamensis, with stearamide significantly decreased adhesion of B. bassiana or M. anisopliae conidia to their cuticles. This evidence indicates that cuticular fatty amides may contribute to L. bostrychophila's tolerance for entomopathogenic fungi by decreasing hydrophobicity and static charge, thereby reducing conidial adhesion.


Subject(s)
Amides/chemistry , Fatty Acids/chemistry , Hypocreales/physiology , Insecta/microbiology , Animals , Cell Adhesion , Coleoptera/microbiology , Hypocreales/growth & development , Insecta/chemistry , Paecilomyces/growth & development , Paecilomyces/physiology
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