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At least 883 records · Page 49Linked to original sources
PubMed1976

Public health advantages of biological insect controls.

Biological control is not new, it is simply newly appreciated. This renewed appreciation stems from the widespread insecticide treadmill which is largely a product of insecticide disruption of the balance of insect communities. Biological control is a natural phenomenon; the regulation of plant and animal numbers by natural enemies. In this broad sense, biological control is vital to public health because it keeps the myriad insect species from out-competing us. It also has direct public health advantages as where natural enemies are manipulated to control disease vectoring insects. Insecticide distruption of biological control by insecticides and the resulting pesticide treadmill have serious public health implications. One is the increased pesticide load in the environment. The other is the acceleration of pesticide resistance in disease vectoring insects. The treadmill and its associated hazards will not abate so long as chemical control dominates our pest management strategy.

Environmental Health↗
PubMed2004

[The role of insects (Blattodea, Diptera, and Hymenoptera) as possible mechanical vectors of helminths in the domiciliary and peridomiciliary environment].

Helminths can be transmitted to human beings in several ways, but little attention has been given to vector or mechanical transmission of infective forms by insects. The present study surveys the helminth species present in three orders of insects that coexist in proximity with the human environment. A total of 700 insects (54 Blattodea, 275 Diptera, and 371 Hymenoptera) were collected and examined externally and individually. In the Blattodea order, only specimens of Periplaneta americana were collected, and 58.3% were carrying the following helminth forms: Oxyuridae eggs (36.4%), Ascaridae eggs (28.04%), Nematoda larvae (4.8%), Cestoda eggs (3.5%), other Nematoda (0.08%), and Toxocaridae eggs (0.08%). No Diptera and Hymenoptera were found to contain parasitic forms. This study evaluates the importance and role of insects as mechanical vectors of helminth parasites, correlated with social and environmental conditions, and suggests the use of these data for preventive purposes.

Animals↗
PubMed2004

Microwave radar detection of stored-product insects.

A microwave radar system that senses motion was tested for capability to detect hidden insects of different sizes and activity levels in stored products. In initial studies, movements of individual adults or groups of Lasioderma serricorne (F.), Oryzaephilus surinamensis (L.), Attagenus unicolor (Brahm), and Tribolium castaneum (Herbst) were easily detected over distances up to 30 cm in air. Boxes of corn meal mix and flour mix were artificially infested with 5-100 insects to estimate the reliability of detection. The likelihood that a box was infested was rated by the radar system on a quantitative scale. The ratings were significantly correlated with the numbers of infesting insects. The radar system has potential applications in management programs where rapid, nondestructive targeting of incipient insect infestations would be of benefit to the producers and consumers of packaged foods.

Animals↗
PubMed2000

Pest control by the release of insects carrying a female-killing allele on multiple loci.

With recent advances in genetics, many new strategies for pest control have become feasible. This is the second article in which we model new techniques for pest control based on the mass release of genetically modified insects. In this article we model the release of insects carrying a dominant and redundant female killing or sterilizing (FK) allele on multiple genetic loci. If such insects are released into a target population, the FK allele can become widely spread in the population through the males while reducing the population each generation by killing females. We allow the number of loci used to vary from 1 to 20. We also allow the FK allele to carry a fitness cost in males due to the gene insertions. Using a model, we explore the effectiveness and optimal strategies for such releases. In the most ideal circumstances (no density-dependence and released insects equal in fitness to wild ones), FK releases are several orders of magnitude more effective than equal sized sterile male releases. For example, a single release of 19 FK-bearing males for every two wild males, with the released males carrying the FK allele on 10 loci, reduces the target population to 0.002% of no-release size. An equal sized sterile release reduces the target population to 5% of no-release size. We also show how the effectiveness of the technique decreases as the fitness cost of the FK alleles in males increases. For example, the above mentioned release reduces the target population to 0.7% of no-release size if each FK allele carries a fitness cost in males of 5%. Adding a simple model for density-dependence and assuming that each of the released males carries the FK allele on six loci, we show that the release size necessary to reduce the target population to 1/100 of no-release size in 10 generations of releases varies from 0.44:1 to 4:1 (depending on parameter values). We also calculate the optimal number of loci on which to put the FK allele under various circumstances.

Alleles↗
PubMed2002

Hole density and capture of stored-product insect pests in grain probe traps.

The relationship between number of holes in a grain probe trap body and capture of stored-grain pests was determined in laboratory tests using adults of the rice weevil, Sitophilus oryzae (L.), the sawtoothed grain beetle, Oryzaephilus surinamensis (L.), and the red flour beetle, Tribolium castaneum (Herbst). Polyvinylchloride (PVC) probe bodies were attached to electronic sensor heads, and insect captures were recorded electronically using an Electronic Grain Probe Insect Counter (EGPIC) system. In comparisons among PVC probe trap bodies with 60-492 holes, tested at 71 insects per kg in 2.8 kg of soft wheat in cylindrical mini-silos, sawtoothed grain beetle and rice weevil captures were directly related to number of holes in the probe trap body, but there was no relationship for red flour beetle capture. Subsequent tests were conducted comparing sawtoothed grain beetle and rice weevil captures in a PVC probe body with 210 holes over a 40-cm long trapping surface with two commercially available probe traps, a polycarbonate (Lexan) probe trap with 180 holes over a 14-cm long trapping surface and a polyethylene (WBII) probe trap with 750 holes over a 34-cm long trapping surface. The highest percentage capture of both species was in the WBII probe trap, but the 210-hole PVC probe body was as effective as the Lexan probe body for rice weevils and sawtoothed grain beetles at 71 and 17 insects per kg of wheat, respectively.

Animals↗
PubMed2005

Performance of an analytical, dual infrared-beam, stored-product insect monitoring system.

A system is described for automated monitoring of pest insects in stored grain. It provides quantitative data indicative of the species of detected insects and is self-calibrating to maintain reliable operation over time across adverse environmental and biological conditions. The system uses electronic grain probes, each with a dual infrared-beam sensor head providing orthogonal views of falling insects. Sensor analog signals are analyzed by an embedded microprocessor, and extracted waveform parameters are transmitted back to a central computer. Filtering algorithms recognize and eliminate false detections due to extraneous (nonfalling) insect activities and provide an indication of species based on body size. Laboratory test data provide species identification templates and an analysis of Montana field test data acquired in aerated and nonaerated bins demonstrates the effectiveness of the filtering algorithms. The described system technology has been licensed by OPIsystems, Inc., Calgary, Alberta, Canada, and is commercially available as Insector.

Animals↗
PubMed2006

Nephrotic syndrome with focal segmental glomerulosclerosis after an insect bite.

AIMS AND METHODS: Focal segmental glomerulosclerosis (FSGS) is a glomerular disease defined by a characteristic histologic pattern that occurs either as a primary kidney disease (primary FSGS) or as a result of a systemic illness (secondary FSGS). Proteinuria, often in the nephrotic range, is the hallmark of FSGS. The occurrence of nephrotic syndrome after an insect sting is rarely reported in the literature. We present a case of nephrotic syndrome with focal segmental glomerulosclerosis with a glomerular tip lesion developing after an insect bite. RESULTS: A 51-year-old Caucasian female was bitten by an insect on her left leg, which immediately became swollen. Generalized edema developed and she was admitted for further investigations. Urinary 24-h protein excretion was 7 g. Percutaneous renal biopsy was performed and showed focal segmental glomerulosclerosis of the tip variant. Nephrotic syndrome was steroid-resistant, and when we added cyclophosphamide for 8 weeks complete remission was achieved. There was no relapse of the disease during the 2-month follow-up. CONCLUSIONS: This report demonstrates the useful role of cyclophosphamide in the treatment of steroid-resistant nephrotic syndrome due to FSGS with glomerular tip lesion. A causal relationship between the insect bite and the nephrotic syndrome is suggested and an immune response could be responsible for the nephrotic syndrome.

Cyclophosphamide↗
PubMed1996

Crossroads, milestones and landmarks in insect development and evolution: implications for systematics.

Our understanding of insect development and evolution has increased greatly due to recent advances in the comparative developmental approach. Modern developmental biology techniques such as in situ hybridization and molecular analysis of developmentally important genes and gene families have greatly facilitated these advances. The role of the comparative developmental approach in insect systematics is explored in this paper and we suggest two important applications of the approach to insect systematics--character dissection and morphological landmarking. Existing morphological characters can be dissected into their genetic and molecular components in some cases and this will lead to more and richer character information in systematic studies. Character landmarking will he essential to systematic studies for clarifying structures such as shapes or convergences, which are previously hard to analyze anatomical regions. Both approaches will aid greatly in expanding our understanding of homology in particular, and insect development in general.

Animals↗
PubMed1976

Insect sting allergy.

Allergy to insect stings may be quite serious, and occasionally lethal. Evaluation of these patients involves careful history taking. Skin testing for the stinging insects is helpful both for diagnosis and finding a beginning dose for hyposensitizing injections. According to many reports, these injections have been very effective in preventing subsequent severe reactions to insect stings. Prompt emergency treatment usually involves adrenalin injections. Insect avoidance procedures are effective.

Ants↗
PubMedDate not supplied

Anaphylaxis to insect sting associated with urticaria pigmentosa.

Anaphylaxis associated with insect stings has been reported to cause approximately 40 deaths per year in the United States. Immunotherapy with venom extracts is a well-established method of treatment of allergy to insect stings. The duration of therapy is based mainly on the initial symptoms and the presence or absence of systemic symptoms during therapy. Evaluation of immunoglobulin E and immunoglobulin G levels as well as repeat skin tests and sting challenges may also provide some additional benefit but are not as useful as the former two criteria. Patients with mastocytosis have a particularly increased risk for anaphylaxis after insect stings. There are many case reports of individuals first diagnosed with mastocytosis after an episode of anaphylaxis after an insect sting, in addition these patients tend to have more severe reactions as well as repeated episodes of systemic reactions during immunotherapy. Early diagnosis of mastocytosis and proper treatment can contribute greatly to the outcome in patients who present with venom allergy.

Anaphylaxis↗
PubMedDate not supplied

[Hypothesis of parasitic stress in parasitized insects caused by microsporidia].

Pathological alterations being similar to those that can be seen while hormonal dysbalance, particularly the increase of juvenile hormone (JH) titre, is one of the consequences of microsporidian infections. Though the increase of JH in insects infected with microsporidia has not been shown directly, there are many indirect proofs of this. It has been believed that JH is produced by microsporidia. But this has not been shown for microsporidia or for other endoparasites. In this article we want to propose another hypothesis. We suppose that during microsporidiosis the following events develop: exhaustion of host nutrition stores and other destructive consequences of microsporidian dwelling in host cells lead to the decrease of host biosynthetical and reparation activity in the infected cells and then to destructive alterations that can be seen by electro-microscopic methods. The infected cells are stressed and then the typical answer for many physiological stresses follows. Secretion of prothoracicotropic hormone by brain neurosecretory cells is inhibited and as a result the production and release of ecdysone is also inhibited and ecdysteroid titre decreases. The activity of JH-esterases is decreased and as a result the JH titre is increased. If microsporidian infection causes the stress in the host cells, the endocrine system will undoubtedly answer to this stress and this answer will definitely be the same as for all other stresses. Thus, in any case JH titre will be increased in infected insects independently of whether microsporidia produce JH or not. So, hormonal alterations in infected insects should be the consequence not of the microsporidian JH production but of the host response reaction to infection. We suppose that microsporidia do not differ from other parasites of insects and that they can not produce JH.

Animals↗
PubMed2004

Anaphylaxis to insect venom.

Systemic reactions to insect stings have a prevalence of about 1% in the adult population. The majority presents with urticaria and angioedema, and the number of deaths per year registered as due to insect stings is 0.1-0.5 per million in the general population. The venom contains peptides and low molecular weight substances such as histamine with an effect on blood vessels, smooth muscles and nerves. High molecular weight components in the venom often have enzyme activity and in addition can act as allergens. It can be difficult to separate allergic from vasovagal or psychogenic reactions based on the clinical history alone. Skin test reaction to venom and/or venom specific IgE in the blood indicate an allergy although a high proportion of people in the general population (up to 20%) with no previous reactions are positive in such tests. Test results can be used to identify the responsible insect species, since allergic reactions can occur against species-specific as well as common allergens in the venom. Following a systemic allergic reaction only about half of the patients will react systemically to a future sting. Immunotherapy with insect venom is effective but the duration of the treatment is still under debate.

Anaphylaxis↗
PubMed2005

Evolution of insect metamorphosis: a microarray-based study of larval and adult gene expression in the ant Camponotus festinatus.

Holometabolous insects inhabit almost every terrestrial ecosystem. The evolutionary success of holometabolous insects stems partly from their developmental program, which includes discrete larval and adult stages. To gain an understanding of how development differs among holometabolous insect taxa, we used cDNA microarray technology to examine differences in gene expression between larval and adult Camponotus festinatus ants. We then compared expression patterns obtained from our study to those observed in the fruitfly Drosophila melanogaster. We found that many genes showed distinct patterns of expression between the larval and adult ant life stages, a result that was confirmed through quantitative reverse-transcriptase polymerase chain reaction. Genes involved in protein metabolism and possessing structural activity tended to be more highly expressed in larval than adult ants. In contrast, genes relatively upregulated in adults possessed a greater diversity of functions and activities. We also discovered that patterns of expression observed for homologous genes in D. melanogaster differed substantially from those observed in C. festinatus. Our results suggest that the specific molecular mechanisms involved in metamorphosis will differ substantially between insect taxa. Systematic investigation of gene expression during development of other taxa will provide additional information on how developmental pathways evolve.

Animals↗
PubMed2006

Insect cells as a new substrate for vaccine production.

Vaccine antigens can be expressed in several expression systems, of which expression in eukaryotic cell lines is a well-known example. Whereas for most current applications cell substrates such as Vero, MRC-5 or chicken embryo fibroblasts are used, cell lines derived from insects present an alternative for the future production of vaccines. Since such substrates are not yet extensively used, knowledge about their feasibility and safety for vaccine antigen production is limited. In the current example, an insect-derived cell line Hi-5, used for the expression of the human papilloma virus L1 antigen, was extensively characterized, in particular for aspects of viral safety. A comprehensive QC testing programme, complemented with additional characterization tests relevant to the insect nature of the cell line, was developed. Current results indicate the satisfactory quality and safety of the Hi-5 cell line. The proposed testing programme could stand as an example for the release testing and further characterization which would be required for insect cell lines.

Animals↗
PubMed2006

[Effects of insecticides on insect pest-natural enemy community in early rice fields].

This paper studied the effects of triazophos, shachongshuang, abamectin, and Bt + imidacloprid on the insect pest-natural enemy community in early rice fields in the Yangtze-Huaihe region of Anhui Province. The results showed that all of the test insecticides had significant effects in controlling the growth of major insect pest populations. The average value of insect pest-natural enemy community diversity under effects of triazophos, shachongshuang, abamectin, and Bt + imidacloprid was 1.545, 1.562, 1.691 and 1.915, respectively, while that in control plot was 1.897. After two weeks of applying insecticides, the plots applied with shachongshuang and abamectin had a similar composition of insect pest-natural enemy community, but the community composition was significantly different between the plots applied with triazophos and Bt + imidacloprid. From the viewpoints of community stability and pest control, Bt + imidacloprid had the best effect, and shachongshuang and abamectin were better than triazophos.

Animals↗
PubMed1991

[Allergy to insect stings].

Components in the insect venom and probably also in their saliva may have direct toxic effects or may cause sensitization and may result in allergic reactions to subsequent stings. In Denmark, only the stings of honey bees and wasps (yellow jackets) are of clinical significance and it is important to be aware that these insects contain separate allergenic components. Clinical manifestations following stings are observed from all of the organ systems on the whole. The commonest are itching of the skin, urticaria, possibly angioedema and slight generalized symptoms with vertigo, headache and fatigue. Life-threatening reactions may also occur and one or two fatal cases are registered annually in Denmark. It may be difficult to decide whether an allergic or a toxic reaction is involved on the basis of the symptoms. Possible IgE-sensitization must therefore be assessed by means of a prick test and measurement of specific IgE. The main treatment in cases of acute systemic reactions is adrenaline which may possibly be supplemented with antihistamine and corticosteroid. In cases of massive local reactions and urticaria, antihistamines will, as a rule, prove sufficient. Hyposensitization with insect venom preparations eliminates the future risk for systemic insect sting reactions practically entirely and this must be recommended for patients with demonstrated IgE-sensitizing and generalized reactions. At present, treatment should be continued for three to five years and protection lasts for a series of years after cessation of treatment.

Humans↗
PubMed1988

Active human tissue plasminogen activator secreted from insect cells using a baculovirus vector.

A baculovirus expression vector was constructed with the tissue plasminogen activator (TPA) cDNA under the control of the viral polyhedrin promoter. After infection of insect cells with the recombinant baculovirus, active TPA was secreted into the medium in which these cells were grown. TPA was isolated from the conditioned media using metal chelate affinity chromatography followed by immunoaffinity purification using mouse monoclonal anti-human TPA coupled to Sepharose. Sodium dodecyl sulfate-gel electrophoresis under reducing conditions and sequence analysis of recombinant human TPA have revealed a two-chain form of the enzyme. The N-terminal amino acid was identified to be serine, indicating that it was processed at its N-terminus by the insect cell culture in a manner similar to that observed for mammalian cells. The relative specific activity of recombinant TPA from insect cells is comparable to that of Bowes melanoma TPA standard. Its activity is stimulated in the presence of fibrinogen fragments, but by a factor about 2.3-fold lower than the Bowes melanoma TPA. The apparent molecular weight of recombinant TPA from insect cells was about 60K by fibrin agar activity gels, suggesting less complex glycosylation than recombinant TPA from mammalian cells.

Amino Acids↗
PubMed1978

Insects and other pests affecting man and animals in Saudi Arabia.

Survey of the insects and other pests attacking farmers and domestic animals was carried out during three successive years (1968, 1969 and 1970) in the Central province of Saudi Arabia. In this paper, the insects and other pests found were given. Also, location and time of appearance for each pest were mentioned. The pests recorded were 6 species of insects belonging to 5 families and 4 orders attacking farmers; 9 species of insects belonging to 8 families and 4 orders, and 9 species of mites and ticks belonging to 5 families attacking domestic animals.

Animal Diseases↗