scholarly journals Experimental studies to study the efficacy of "Tarzan, VE" against Blattoptera representatives

2021 ◽  
Vol 15 (2) ◽  
pp. 80-87
Author(s):  
R. M. Akbaev ◽  
L. V. Nacheva ◽  
A. A. Generalov
Keyword(s):  
Topical Application ◽  
Experimental Studies ◽  
German Cockroach ◽  
Development Stage ◽  
Laboratory Culture ◽  
Maximum Effect ◽  
Test Surface ◽  
Larval Stages ◽  
Previously Treated ◽  
Surface Glass

The purpose of the research is studying the efficacy of "Tarzan, VE" against representatives of the Blattoptera order, Blattella germanica.Materials and methods. Experimental studies to study the efficacy of "Tarzan, VE" on representatives of the Blattoptera order were performed for two weeks at the premises of the Skryabin MVA (Moscow) and the KemSMU (Kemerovo). The study object was the red German cockroach B. germanica, a laboratory culture of which was grown in the MVA insectarium. Experiments 1 and 2 consisted of three tests of three sets each: a test to study the efficacy of the drug against cockroaches by the topical application; and a test to study the efficacy of "Tarzan, VE" against cockroaches by the forced exposure of arthropods to test surfaces, namely, plywood or glass previously treated with the drug in different concentrations. Dead insects were counted after a day.Results and discussion. We established the efficacy of "Tarzan, VE" in the form of an active substance in different dilutions against cockroaches B. germanica of both sexes using the topical application. Its efficiency decreases to 97% when diluted 1000 times (0.001N). With forced exposure to treated test surface (plywood), the efficacy of “Tarzan, VE” depended on the substance diluted: 90% at 0.01N, 83.3% at 0.005N, and 50% at 0.001N. The maximum effect of "Tarzan, VE" was observed when using the method of forced exposure of cockroaches to the treated test surface, glass. The efficacy of the drug in this case was 100% regardless of the sex and development stage of cockroaches. It was found that different concentrations of the insecticide had a toxic effect on the imago of both sexes and larval stages of cockroach development. The insecticidal nature of the drug is ensured by the use of zeta-cypermethrin as an active ingredient. "Tarzan, VE" insecticide can be recommended to control and prevent the distribution of B. germanica. 

Воздействиеультразвуковогополянадинамическуювязкостьводы

2019 ◽  
pp. 27-29
Author(s):  
P. Vikulin ◽  
K. Khlopov ◽  
M. Cherkashin
Keyword(s):  
Dynamic Viscosity ◽  
Experimental Studies ◽  
Ultrasonic Field ◽  
Maximum Effect ◽  
Ultrasonic Frequency ◽  
Ultrasonic Vibrations ◽  
Wastewater Disposal ◽  
Laboratory Setup ◽  
Sonic Treatment ◽  
The Impact

Enhancing water purification processes is provided by various methods including physical ones, in particular, exposure to ultrasonic vibrations. The change in the dynamic viscosity of water affects the rate of deposition of particles in the aquatic environment which can be used in natural and wastewater treatment. At the Department Water Supply and Wastewater Disposal of the National Research Moscow State University of Civil Engineering experimental studies were conducted under laboratory conditions to study the effect of ultrasound on the change in the dynamic viscosity of water. A laboratory setup has been designed consisting of an ultrasonic frequency generator of the relative intensity, a transducer (concentrator) that transmits ultrasonic vibrations to the source water, and sonic treatment tanks. Experimental studies on the impact of the ultrasonic field in the cavitation mode on the dynamic viscosity of the aqueous medium were carried out the exposure time was obtained to achieve the maximum effect.Интенсификация процессов очистки воды осуществляется с помощью различных методов, в том числе и физических, в частности воздействием ультразвуковых колебаний. Изменение динамической вязкости воды влияет на скорость осаждения частиц в водной среде, что может быть использовано в процессах очистки природных и сточных вод. На кафедре Водоснабжение и водоотведение Национального исследовательского Московского государственного строительного университета в лабораторных условиях проведены экспериментальные исследования по изучению влияния ультразвука на изменение динамической вязкости воды. Разработана схема лабораторной установки, состоящая из генератора ультразвуковых частот с соответствующей интенсивностью, преобразователя (концентратора), передающего ультразвуковые колебания в исходную воду, и емкости для озвучивания. Выполнены экспериментальные исследования по влиянию ультразвукового поля в режиме кавитации на динамическую вязкость водной среды, получено время экспозиции для достижения максимального эффекта.

scholarly journals Effect of body size heterogeneity on the aggressive behavior of larvae of matrinxã, Brycon amazonicus (Characiformes, Bryconidae)

2018 ◽  
Vol 48 (4) ◽  
pp. 304-310 ◽  
Author(s):  
Thaís Billalba CARVALHO ◽  
Ellen Cristina Monteiro de SOUZA ◽  
Jaquelinne PINHEIRO-DA-SILVA ◽  
Marle Angélica VILLACORTA-CORREA
Keyword(s):  
Body Size ◽  
Aggressive Behavior ◽  
Larval Development ◽  
Production Systems ◽  
Larval Mortality ◽  
Development Stage ◽  
Breeding Systems ◽  
Aggressive Interactions ◽  
Larval Stages ◽  
Size Heterogeneity

ABSTRACT Brycon amazonicus is a native Amazonian fish that is important for aquaculture in South America. Larval mortality is high in this species in intensive breeding systems due to aggressiveness among larvae. The present study investigated experimentally the effects of body size heterogeneity on the aggressive behavior and survival of B. amazonicus during the early stages of larval development. Two treatments (larvae groups with homogeneous and heterogeneous body size) were evaluated throughout early larval stages tested at six time points: 12, 24, 36, 48, 60 and 72 hours after hatching (HAH). Two experiments quantified, respectively, aggressive interactions and mortality rates among larvae at each time point. The frequency of aggressive interactions exhibited by the less aggressive larvae in each replicate was higher in the homogeneous size treatment. Aggressiveness was higher at 12 HAH, decreasing thereafter, and increasing again at 72 HAH. The mortality rate significantly increased with the larval stage, and was higher in the homogeneous than in the heterogeneous sized groups. Our results showed that aggressiveness in B. amazonicus larvae is affected by size variability and larval development stage. This knowledge about larval behavior is important to develop measures to improve larval health and survival in intensive production systems for this species.

scholarly journals Description of the first five larval stages of Plesionika narval (Fabricius, 1787) (Crustacea, Decapoda, Pandalidae) obtained under laboratory conditions

Zootaxa ◽  
2009 ◽  
Vol 2206 (1) ◽  
pp. 45-61 ◽  
Author(s):  
JOSÉ MARÍA LANDEIRA ◽  
FERNANDO LOZANO-SOLDEVILLA ◽  
JUAN IGNACIO GONZÁLEZ-GORDILLO
Keyword(s):  
Laboratory Culture ◽  
Larval Stages ◽  
Laboratory Conditions

The first five zoeal stages of Plesionika narval were obtained from 15 days of laboratory culture. All larval stages are described and illustrated in detail. Zoeal characters are compared with the previous described larvae of Plesionika acanthonotus and Plesionika edwardsii and with undetermined zoeas of Pandalidae from plankton samples.

Anatomy of anuran tadpoles from lentic water bodies: systematic relevance and correlation with feeding habits

Zootaxa ◽  
2007 ◽  
Vol 1600 (1) ◽  
pp. 1-175 ◽  
Author(s):  
M. FLORENCIA VERA CANDIOTI
Keyword(s):  
Body Length ◽  
Prey Size ◽  
Feeding Habits ◽  
Experimental Studies ◽  
Morphological Characters ◽  
Gut Content ◽  
Canonical Ordination ◽  
Larval Stages ◽  
Food Particles ◽  
The Relationship

I studied anatomy, gut content, and the relationship among these traits in a set of anuran tadpoles. Larval stages (mainly Gosner stages 31–36) of nineteen species from various lentic environments were selected. Morphological characters from the skeleton, musculature, oral apparatus and buccopharyngeal cavity were recorded, and a gut content analysis was performed, with emphasis on food size distribution. Ordination techniques were applied in order to find patterns of similarity in morphology and gut content. Canonical ordination methods were used to investigate the relationship among gut content, morphology, and phylogeny in the species considered. The results show that several skeletal, muscular, and buccal characters are relatively maintained within genera. Other features, which have appeared independently in different lineages, reflect convergence phenomena in some cases related to ecological aspects. The configuration of the hyobranchial skeleton, the development of the buccal floor depressor and levator muscles, and mouth gape width correlate with prey size. In some species, morphology is clearly related with feeding. Tadpoles that ingest large food particles relative to their body length present morphological traits attributable to macrophagy. Taxonomically unrelated tadpoles of Dendropsophus nanus, D. microcephalus and Ceratophrys cranwelli possess hyobranchial skeletons with robust, rostrocaudally long ceratohyals and reduced branchial baskets with short ceratobranchials devoid of lateral projections and spicules. Lepidobatrachus llanensis tadpoles have laterally extended ceratohyals which, along with the lateral extension of the jaws, result in a very wide oral apparatus and an ample buccopharyngeal cavity that allows the tadpole to ingest large and whole prey; the branchial basket, although its ceratobranchials lack lateral projections and spicules, is slightly reduced in area. The four species mentioned have a noticeable development of the buccal floor depressor muscles, and buccal cavities with scarce filtering and entrapping structures. In Elachistocleis bicolor, Dermatonotus muelleri, Chiasmocleis panamensis, and Xenopus laevis tadpoles, the branchial basket occupies >70% of the total hyobranchial skeleton area, and the hypobranchial plates are highly reduced; the buccal floor levator muscles are well-developed, with an increased site of attachment on the ventral expansion of the lateral process of the ceratohyal; the scarcity of the filtering structures in the buccopharyngeal cavity are balanced with the great development of the branchial filters and secretory zones; all these features relate to a diet based on small particles not significantly different from those of most other species; however, experimental studies show that species with similar hyobranchial apparatus and muscles are the most efficient when retaining minute particles. Finally, a large group of species present generalized morphological characters, such as a branchial basket occupying about 50% of the total hyobranchial apparatus, intermediate values of mouth gape width and buccal floor levator / depressor muscles ratio, and abundant filtering structures in the buccopharyngeal cavity; these species feed frequently on food particles between 1–30% of the tadpole body length; however, in some of the species, macrophagous diets are also reported in the literature, indicating that this morphology is flexible in more ample prey size ranges.

Experimental Study on Sensitivity Damage of Offshore High-Porosity and High-Permeability Reservoir

2014 ◽  
Vol 926-930 ◽  
pp. 111-114
Author(s):  
Jun Yi Liu ◽  
Zheng Song Qiu ◽  
Wei An Huang ◽  
Yang Luo
Keyword(s):  
Experimental Studies ◽  
Wide Distribution ◽  
Development Stage ◽  
Stress Sensitivity ◽  
Laboratory Evaluation ◽  
Drilling Fluids ◽  
High Porosity ◽  
High Permeability ◽  
Intrusion Prevention ◽  
Water Sensitivity

Offshore high-porosity and high-permeability reservoirs, characterized by large pore throat, wide distribution of pore size and enriched sensitive minerals, are easily damaged due to improper use of drilling fluids and completion fluids during the development stage. A series of experimental studies were carried out on the sensitivity damage analysis including X-ray diffraction, scanning electron microscopy, mercury injection porosimetry and core flow experiment. According to the laboratory evaluation results, the reservoir SZLF of high-porosity and high-permeability existed strong water sensitivity and mid to strong stress sensitivity. Furthermore, shielding and temporary plugging technique applied for reservoir protection was put forward, and laboratory tests showed that it had a better effect on solid intrusion prevention.

The Biology of Cephalonomia waterstoni Gahan (Hym., Bethylidae), a Parasite of Laemophloeus (Col., Cucujidae)

1950 ◽  
Vol 41 (1) ◽  
pp. 79-97 ◽  
Author(s):  
L. H. Finlayson
Keyword(s):  
Life Cycle ◽  
Insect Pests ◽  
Sucrose Solution ◽  
Large Population ◽  
Laboratory Culture ◽  
Larval Stages ◽  
Marked Preference ◽  
Laboratory Investigations ◽  
C 30 ◽  
Duration Of Development

The paper describes field and laboratory investigations on the bionomics of Cephalonomia waterstoni, a Bethylid parasite of Laemophloeus spp. A table is given in which are listed all the Bethylids attacking insect pests of stored products to which reference could be found in the literature.An infestation of Laemophloeus, associated with two “hot spots” in Manitoba wheat, which supported a large population of Cephalonomia is described.A simple technique for the laboratory culture of Cephalonomia is described.The life-cycle of C. waterstoni with Laemophloeus ferrugineus as host has been worked out.The lengths of egg, larval and cocoon (prepupal and pupal) stages at combinations of 25°C, 30°C. and 60 per cent., 80 per cent. R.H. are given. The egg and larval stages are short, lasting for about six days at 25°C. and four days at 30°C.Within the limits used, the relative humidity appears to have no effect on the duration of development at any stage. On the other hand, temperature exerts a considerable influence; the life-cycle at 30°C. is completed in two weeks but at 25°C. it takes three weeks.Again within the limits used, the mortality appears to increase with decrease in saturation deficit. Mortality ranged from 9 per cent, at S.D. 12·7 mm. to 36·5 per cent, at S.D. 5·0 mm.Without food or water at all combinations of 25–30°C. and 60–80 per cent. R.H. adults live for about four days, with a range of 0·5–9·5 days. There is no difference between the sexes. Unexplained contradictory results were obtained in two experiments.With normal or paralysed host larvae available at 30°C. and 80 per cent. R.H., males live no longer than when no food or water is available but females live for about five weeks at 25°C. and 80 per cent. R.H. and for about four weeks at 30°C. and 80 per cent. R.H.Males fed with sucrose solution at 30°C. and 80 per cent. R.H. live for several days longer than when starved : females live for the same length of time as when fed with host larvae.The pre-oviposition period at 25°C. and 80 per cent. R.H. is about five days; at 30°C. and 80 per cent. R.H. about one and a half days.Fecundity. At 25°C. and 80 per cent. R.H., Cephalonomia lays about 40 eggs on 30 host larvae : at 30°C. and 80 per cent. R.H., about 65 eggs on 40 larvae.Cephalonomia females readily oviposit on larvae that have been paralysed some time previously, and can be induced to oviposit on larvae already bearing eggs.Virgin females produce only male offspring (arrhenotoky).Eggs are laid in groups of one, two or three (rarely four) per larva. Single eggs produce mainly females ; pairs produce mainly one male and one female ; trios produce mainly one male and two females. At 25°C. and 80 per cent. R.H. more single eggs are laid than pairs ; at 30°C. and 80 per cent. R.H. more pairs are laid than singles. This results in the production of a higher proportion of females at 25°C. than at 30°C. The incidence of trios at both temperatures is low.C. waterstoni is equally viable on L. minutus, L. ferrugineus and L. turcicus but shows a marked preference for L. ferrugineus.

The development of Neomenia carinata Tullberg (Mollusca Aplacophora)

1960 ◽  
Vol 153 (951) ◽  
pp. 263-278 ◽  
Keyword(s):  
Nervous Tissue ◽  
Ventral Side ◽  
Laboratory Culture ◽  
Culture Vessel ◽  
Natural Diet ◽  
Larval Stages ◽  
Cerebral Ganglia ◽  
Locomotory Organ ◽  
Pass Through ◽  
Food Reserves

The chance finding of a single adult specimen of the solenogastre Neomenia carinata Tullberg 1875 rendered possible an embryological study of this species. Little is known concerning the ontogeny of the Aplacophora and a number of important questions, such as the fate of the larval test, the nature of the abapical depression visible during gastrulation and the presence or absence of any evidence of metamery, remain to be elucidated. Embryos, larvae and post-larvae were maintained in laboratory culture a t 10 °C. No description can be given of the early cleavage stages since the eggs when found were always well advanced. Each egg is enclosed by a single membrane. Gastrulation begins on the second day, by a process of immigration of the abapical cells; the abapical depression, often called a blastopore, is shown to be of an unusual character and is to be referred to as a pseudo -blastopore. This pseudo-blastopore is merely a relatively shallow depression marking the area at which immigration is occurring. After the completion of gastrulation, the cells lining the pseudo-blastopore are the prospective trunk ectoderm. The endoderm and mesoderm lie within the embryo and have no communication with the exterior. The remaining cells form the larval test, except for an apical quartet which will develop into the larval apical plate and for six small patches of cells which will give rise to much of the definitive nervous system. The apical/abapical axis of the gastrula is coincident with the antero-posterior axis of the adult solenogastre. The embryos leave their egg membranes on the third day and swim by means of the cilia of the larval test. This test becomes organized into a series of tiers of regularly shaped cells. The main tier is the prototroch, on which is developed a strong equatorial band of locomotory cilia. The larvae are not negatively geotactic and swim close to the bottom of a culture vessel. Proliferation of the definitive nervous tissue begins just before hatching, from six areas of larval test ectoderm on the future ventral side. Nervous elements are cut off inwards at the bases of shallow ectodermal depressions; they come to aggregate into cerebral and ventral (pedal) ganglia. By the seventh day the rudiment of the adult trunk is visible, protruding through the pseudo-blastopore. On its tip is the yolk-laden, ciliated, larval telotroch. The remainder of the trunk is 'Unciliated (except for a median longitudinal ventral ciliated band) but bears numerous pointed calcareous spicules. The length of the trunk rudiment increases by repeated division of the ectodermal cells within the pseudo-blastopore. The midgut passes down into the trunk and with it travel mesodermal elements and a pair of bands of nervous tissue which will form the ventral (pedal) cords. Proctodaeal and stomodaeal invaginations place the midgut in communication with the exterior but the larvae do not feed. The ‘ pygidial ’ development of the trunk of Neomenia resembles strongly that process as found in many annelids but it must be noted that no trace of metameric segmentation of this trunk is visible at any stage in the development of Neomenia . At no stage does the trunk bear overlapping dorsal spicules like those described by Pruvot for Nematomenia ; it seems probable on embryological grounds that the solenogastres are more closely allied to the primitive Lamellibranchia than to the Polyplacophora. Metamorphosis is considered to include only those changes occurring from the tenth to the thirteenth days, during which period the larva exchanges a pelagic for a benthic life. The trunk comes to form by far the greater proportion of the late larva and swimming becomes impossible. The larval test cells lose their orderly arrangement, the prototroch ceases to exist as a co-ordinated locomotory organ and the whole larval test becomes enclosed within the blastocoel of the trunk by the anterior extension and fusion of folds of definitive ectoderm. Similarly, the larval telotroch enters the trunk blastocoel posteriorly. From the blastocoel these yolk-laden cells of the larval locomotory and sensory apparatus pass through the midgut wall into the digestive cells; here they are broken down into small clusters of yolk granules which form the main identifiable food reserve of the post-larva. The mouth and anus, which, before metamorphosis, were directed posteriorly, are now directed ventrally; they lie at the anterior and posterior extremities of a median ventral longitudinal ciliated groove, the so-called pedal groove of the post-larva. This groove is at no stage employed as a pedal sole. The sites from which nervous elements were proliferated during larval life are obliterated at metamorphosis. In the post-larva, two new pairs of ectodermal nervous depressions develop. Both give rise to tubular strands of nervous tissue which extend to and fuse with the cerebral ganglia. Lateral (pleural) cords develop as outgrowths from the cerebral ganglia. Post-larval stages lived in the laboratory without food for up to 10 weeks; they were subsisting entirely on their food reserves. The natural diet of the species is unknown. During the ninth week after metamorphosis the atrium appeared, as a capacious invagination around the mouth. No radula, gills, cloaca, heart, coelomoducts or gonads developed before the young stages died; all but the first are known to be present in the adult Neomenia . A bibliography of works dealing with the ontogeny of Aplacophora is given.

The role of biotic factors in the transmission of free-living endohelminth stages

Parasitology ◽  
2008 ◽  
Vol 135 (4) ◽  
pp. 407-426 ◽  
Author(s):  
D. W. THIELTGES ◽  
K. T. JENSEN ◽  
R. POULIN
Keyword(s):  
Abiotic Factors ◽  
Experimental Studies ◽  
Global Changes ◽  
Parasite Transmission ◽  
Helminth Parasites ◽  
Biotic Factors ◽  
Free Living ◽  
Anthropogenic Pollutants ◽  
Larval Stages

SUMMARYThe transmission success of free-living larval stages of endohelminths is generally modulated by a variety of abiotic and biotic environmental factors. Whereas the role of abiotic factors (including anthropogenic pollutants) has been in focus in numerous studies and summarized in reviews, the role of biotic factors has received much less attention. Here, we review the existing body of literature from the fields of parasitology and ecology and recognize 6 different types of biotic factors with the potential to alter larval transmission processes. We found that experimental studies generally indicate strong effects of biotic factors, and the latter emerge as potentially important, underestimated determinants in the transmission ecology of free-living endohelminth stages. This implies that biodiversity, in general, should have significant effects on parasite transmission and population dynamics. These effects are likely to interact with natural abiotic factors and anthropogenic pollutants. Investigating the interplay of abiotic and biotic factors will not only be crucial for a thorough understanding of parasite transmission processes, but will also be a prerequisite to anticipate the effects of climate and other global changes on helminth parasites and their host communities.

Observations on the larvae and pupae of Pieris brassicae (L.) in a laboratory culture

1962 ◽  
Vol 53 (2) ◽  
pp. 417-436 ◽  
Author(s):  
W. A. L. David ◽  
B. O. C. Gardiner
Keyword(s):  
Constant Temperature ◽  
Dark Period ◽  
Continuous Light ◽  
Laboratory Culture ◽  
Pieris Brassicae ◽  
Continuous Darkness ◽  
Average Width ◽  
Larval Stages ◽  
The Hours ◽  
Pass Through

The work described in this paper forms the final part of an investigation into the biology and breeding of Pieris brassicae (L.) in captivity and concerns the larvae and the pupae.The larvae of the Cambridge stock used in this investigation were found to pass through five instars in the course of their development at temperatures between 12·5 and 30°C. At the lower temperature, development was completed in 46·5 days and at the higher temperature in 11 days.The average width of the head capsules in each instar was not affected by the temperature at which the larvae were reared, it showed little variation, and it never overlapped with that of the preceding or ensuing instar and, therefore, provides a certain way of determining the instar of any larva.At 20°C., isolated larvae and larvae kept in crowded cultures completed their development in approximately the same time—19·6 and 18·8 days, respectively.The average consumption of food during the whole larval period was determined in two experiments, in which it was found to be 1·42 and 1·29 g. of fresh leaves per g. of larva per day, respectively.The duration of the pupal period ranged from 7·5 days at 30°C. to about 40 days at 12·5°C.The adults showed a definite diel rhythm of emergence. When kept at a constant temperature, with a photoperiod from 6 a.m. to 10 p.m., nearly all the insects emerged during the dark period and that immediately following it—actually between the hours of 1 a.m. and 9 a.m. If the photoperiod is displaced 12 hours, the emergence is also displaced by the same amount, to correspond with the new dark period. If, instead of keeping the temperature constant, with the photoperiod 6 a.m. to 10 p.m., it is allowed to fluctuate, as it does naturally in June, the emergence is delayed and instead of occurring in darkness and the early hours of the morning as it does at a constant temperature, it takes place mainly during the morning and the afternoon. When insects, which have been reared at a constant temperature and a photoperiod from 6 a.m. to 10 p.m., are allowed to emerge at a constant temperature, in continuous light, there is very little evidence of a diel rhythm of eclosion but if the insects are kept in continuous darkness they show a definite rhythm of emergence. If the pupae are kept in constant light but the temperature is allowed to fluctuate, most of the adults emerge during the warmer period of the cycle.Diapause in the pupa of P. brassicae is mainly determined by the photoperiod and the temperature during the larval stages. At 20°C., larvae reared in continuous darkness do not form diapause pupae; as the daily photoperiod increases, the percentage of diapause pupae formed also increases until, at a photoperiod of 12 hours, only diapause pupae are formed. Beyond this point the percentage of diapause pupae again declines until, with a photoperiod of about 18 hours, only non-diapause pupae are formed. At higher temperatures similar trends are observed but lower percentages of diapause pupae are formed at all photoperiods.In P. brassicae there is no evidence that a short, sharply defined period of a day or two exists in the course of the life of the larvae during which the photoperiod operates to influence diapause.Non-diapause pupae produced from larvae reared in continuous darkness and from larvae reared in long days (over 15 hours' light) appear to contain a growth-promoting hormone capable of causing the emergence of diapause pupae.

Sign in / Sign up

Export Citation Format

Share Document