LABORATORY STUDIES ON THE TOXICITY OF INSECTICIDES TO THE BERTHA ARMYWORM (MAMESTRA CONFIGURATA) (LEPIDOPTERA: NOCTUIDAE)

1975 ◽  
Vol 107 (8) ◽  
pp. 865-872 ◽  
Author(s):  
C. R. Harris ◽  
S.A. Turnbull
Keyword(s):  
Direct Contact ◽  
Developmental Stages ◽  
Contact Toxicity ◽  
Mamestra Configurata ◽  
Larval Stages ◽  
Large Numbers ◽  
Third Stage ◽  
History Of ◽  
Dual Objectives ◽  
Bertha Armyworm

AbstractThis study had dual objectives: to select a series of insecticides toxic to the bertha armyworm, Mamestra configurata (Walk.), and to determine susceptibility of the various developmental stages to insecticides. Pupae were collected from infested rapeseed fields in Alberta and a laboratory rearing procedure suitable for production of large numbers of insects was devised. The direct contact toxicity of 50 insecticides to third-stage larvae was assessed. Methomyl and DDT were included as standard insecticides. None of the experimental insecticides was as toxic as methomyl but about one half were more toxic than DDT. Tests with representative organochlorine, organophosphorus, and carbamate insecticides indicated that all caused rapid knockdown of third-stage larvae. There was no evidence of subsequent recovery. After the life history of the bertha armyworm under controlled environmental conditions was determined, tests were conducted to ascertain the susceptibility of the various developmental stages to methomyl, chlorpyrifos, leptophos, and methidathion. Eggs and first and second stage larvae were more susceptible to direct contact applications of the insecticides than were the later larval stages, pupae, and adults.

Studies on the life-history of Bunostomum phlebotomum (Railliet, 1900), a hookworm parasite of cattle

Parasitology ◽  
1946 ◽  
Vol 37 (3-4) ◽  
pp. 192-201 ◽  
Author(s):  
J. F. A. Sprent
Keyword(s):  
Infective Larva ◽  
Stage Larva ◽  
Fourth Stage ◽  
Larval Stages ◽  
The Third ◽  
Third Stage ◽  
History Of ◽  
Time Required ◽  
Cutaneous Blood ◽  
Fourth Stage Larva

A description is given of the processes of copulation, formation of the egg and spermatozoon, cleavage, embryogeny and hatching in B. phlebotomum. These processes were found to be essentially similar to those in other strongyle nematodes.The anatomy of the first three larval stages is described and the observations of Conradi & Barnette (1908) and Schwartz (1924) were largely confirmed.Penetration of the skin of calves by the infective larva was observed histologically. The larvae were found to have reached the dermis within 30 min. and to have penetrated the cutaneous blood vessels within 60 min. of application to the skin. The larvae were found in the lung where the third ecdysis was in progress 10 days after penetration of the skin. A description is given of the growth of the third-stage larva in the lung, the changes which take place during the third ecdysis, and the anatomy of the fourth-stage larva.The fourth-stage larvae exsheath in the lungs and travel to the intestine. After a period of growth in which sexual differentiation takes place, the fourth ecdysis occurs and the adult parasite emerges. The time required for the attainment of maturity was found to be somewhere between 30 and 56 days after penetration of the skin.This paper was written at the Ministry of Agriculture and Fisheries Veterinary Laboratories, Wey-bridge, and the writer would like to express his gratitude to the Director, Prof. T. Dalling, also to Dr W. R. Wooldridge, chairman of the Council of the Veterinary Educational Trust for their help and encouragement. The writer's thanks are also due to Dr H. A. Baylis, Prof. R. T. Leiper and Dr E. L. Taylor for their advice and help on technical points, and to Mr R. A. O. Shonekan, African laboratory assistant, for his able co-operation.

scholarly journals Seasonal occurrence of some larval stages of endoparasites in three cyprinids from the Nwanedi-Luphephe dams, the Limpopo River System, South Africa

2015 ◽  
Vol 52 (3) ◽  
pp. 229-235 ◽  
Author(s):  
E. M. Mbokane ◽  
J. Theron ◽  
W. J. Luus-Powell
Keyword(s):  
Developmental Stages ◽  
River System ◽  
Intestinal Wall ◽  
The Body ◽  
Seasonal Occurrence ◽  
Seasonal Fluctuations ◽  
Metazoan Parasites ◽  
Larval Stages ◽  
Parasite Communities ◽  
Third Stage

Abstract This study provides information on seasonal occurrence of developmental stages of endoparasites infecting three cyprinids in the Nwanedi-Luphephe dams, Limpopo River System. Labeobarbus marequensis (Smith, 1841), Barbus trimaculatus Peters, 1852 and Barbus radiatus Peters, 1853 were investigated seasonally from January 2008 to October 2008. The following larvae of metazoan parasites were collected: Diplostomum sp. from the eyes of L. marequensis and B. trimaculatus; Ornithodiplostomum sp. from the gills of B. trimaculatus; Posthodiplostomum sp. from muscle, skin and fins of B. trimaculatus and B. radiatus; third-stage Contracaecum larvae (L3) from the mesentery fats and on the liver lobes of L. marequensis and B. trimaculatus and gryporynchid cestode larvae from the outer intestinal wall of B. radiatus. All the flukes encountered were metacercariae. Diplostomum sp. and Contracaecum sp. dominated the parasite communities. Their prevalence exhibited seasonal fluctuations with maxima in summer. Factors likely to influence fish infection such as the body size of fish and their condition factors were also briefly considered in this study.

scholarly journals Evaluation of Effective and Practical Euthanasia Methods for Larval African Clawed Frogs (Xenopus laevis)

2020 ◽  
Vol 59 (3) ◽  
pp. 269-274
Author(s):  
Ilana A Galex ◽  
Cameron M Gallant ◽  
Nicole D'Avignon ◽  
Lauren M Kuchenbrod ◽  
Craig A Fletcher ◽  
...  
Keyword(s):  
Xenopus Laevis ◽  
Developmental Stages ◽  
Age Group ◽  
Research Model ◽  
Larval Stages ◽  
Large Numbers ◽  
Guidance Documents ◽  
Stock Solutions ◽  
Tricaine Methanesulfonate ◽  
Tank Water

Larval, or tadpole-stage Xenopus laevis frogs are a popular research model for developmental biology and disease studies. Existing euthanasia guidance documents offer recommendations for both eggs and adult stages, yet do not specifically address the larval stage. Data evaluating effective euthanasia methods for groups of X. laevis tadpoles would therefore be useful. The goal of the current study was to evaluate the efficacy of various immersion euthanasia procedures on tadpoles: tricaine methanesulfonate (MS222) at 6 g/L, eugenol at 800 μL/L and rapid chilling (2 to 4 °C). We also evaluated tadpoles at various developmental stages (NF stages 46, 47 and 49). Tadpoles (n = 70) were exposed to euthanasia solution for 15 min, and controls (n = 40) were placed in housing tank water for 15 min. All animals were then placed in recovery tanks containing housing tank water for 4 h to confirm irreversibility of each agent. Cessation of the heartbeat was assessed at the end of euthanasia solution exposure and at each hour thereafter. We found that immersion in a 6 g/L solution of MS222 resulted in 100% euthanasia of all larval stages tested. Conversely, eugenol produced variable euthanasia rates that were affected by both age group and batches of stock solutions. Rapid chilling was completely ineffective as a euthanasia method in our study. Based on our findings, we recommend MS222 as an effective and practical means of euthanizing large numbers of X. laevis tadpoles.

scholarly journals The biology of Limacina retroversa

1954 ◽  
Vol 33 (2) ◽  
pp. 297-312 ◽  
Author(s):  
J. E. Morton
Keyword(s):  
Life History ◽  
Breeding Season ◽  
Detailed Account ◽  
Larval Stages ◽  
Large Numbers ◽  
History Of ◽  
Clione Limacina

The Plymouth Fauna List contains records of two genera of pteropods, Limacina and Clione. Of the first, Limacina retroversa (Flem.) is by far the better-known species, apparently occurring regularly at Plymouth in large numbers in townettings from outside, and sometimes inside, the Sound. It breeds at Plymouth from June to August, and Lebour (1932) has given a detailed account of its breeding and larval stages and has discussed its role in the plankton. The second species of Limacina at Plymouth is lesueuri (d'Orbigny), which has been observed from time to time since 1906, when it was very common. The last record in the Fauna is off the Breakwater in 1920. Of the gymnosomatous pteropods, Clione limacina Phipps is the only species regularly occurring. Lebour (1931) has described the life history of this form, and mentions February to August as its months of greatest abundance. Its breeding season is June to August. Another gymnosome, tentatively referred to as Clionina longicauda, is reported by Russell (1936), and from the specimen department at Plymouth Laboratory the writer obtained some preserved specimens, not easily identifiable, of a Pneumodermopsis taken locally; its species is perhaps ciliata, recorded by Massy (1917) from the Irish Coast.

LIFE HISTORY AND IMMATURE STAGES OF THE PARASITOID MICROPLITIS MEDIATOR (HYMENOPTERA: BRACONIDAE), REARED ON THE BERTHA ARMYWORM MAMESTRA CONFIGURATA (LEPIDOPTERA: NOCTUIDAE)

1986 ◽  
Vol 118 (5) ◽  
pp. 487-491 ◽  
Author(s):  
A.P. Arthur ◽  
P.G. Mason
Keyword(s):  
Biological Control ◽  
Life History ◽  
Immature Stages ◽  
Mamestra Configurata ◽  
Microplitis Mediator ◽  
Larval Stages ◽  
Lepidoptera Noctuidae ◽  
Bertha Armyworm

AbstractMicroplitis mediator (Haliday) is being considered for introduction into Saskatchewan to augment the biological control of the bertha armyworm, Mamestra configurata Walker. It was reared in the laboratory on larvae of the bertha armyworm. Notes on the life history and descriptions of the egg and three larval stages are given.

The plankton and the benthos: origins and early history of an evolving relationship

Paleobiology ◽  
1994 ◽  
Vol 20 (3) ◽  
pp. 297-319 ◽  
Author(s):  
Philip W. Signor ◽  
Geerat J. Vermeij
Keyword(s):  
Benthic Communities ◽  
Marine Species ◽  
Suspension Feeding ◽  
Marine Animals ◽  
Suspension Feeders ◽  
Larval Stages ◽  
Large Numbers ◽  
Ultimate Cause ◽  
Marine Realm ◽  
History Of

Modern marine plankton communities include a broad diversity of metazoans that are suspension-feeding or micropredatory as adults. Many benthic marine species have larval stages that reside, and often feed, in the plankton for brief to very long periods of time, and most marine benthic communities include large numbers of suspension-feeders. This has not always been the case. Cambrian benthic communities included relatively few suspension-feeders. Similarly, there were few metazoan clades represented in the plankton, either as adult suspension-feeders or as larvae. Review of the fossil record suggests that the diversification of the plankton and suspension-feeding marine animals began in the Late Cambrian and continued into the Ordovician. These changes were accompanied by, and probably influenced, concurrent major changes in the marine realm, including an increase in tiering within benthic communities, the replacement of the Cambrian fauna by the Paleozoic fauna, and a general taxonomic diversification. The ultimate cause of these changes is uncertain, but it appears likely that the plankton was and is a refuge from predation and bioturbation for adults and larvae alike. The expansion in plankton biomass thus provided increased ecological opportunities for suspension-feeders in the plankton and benthos.

The life history of Hysterothylacium analarum Rye and Baker, 1984 (Nematoda: Anisakidae) in Lepomis gibbosus (Pisces: Centrarchidae) in southern Ontario, Canada

1992 ◽  
Vol 70 (8) ◽  
pp. 1576-1584
Author(s):  
Leslie A. Rye ◽  
Michael R. Baker
Keyword(s):  
Seasonal Pattern ◽  
Late Summer ◽  
Intestinal Lumen ◽  
Lepomis Gibbosus ◽  
Fourth Stage ◽  
Larval Stages ◽  
Second Stage ◽  
Third Stage ◽  
History Of ◽  
Gravid Females

Larval stages of Hysterothylacium analarum are described from Lepomis gibbosus in Dawson Pond, Ontario (45°10′N, 78°50′W). Second-stage larvae were easily distinguished from all other stages by the presence of a conical boring tooth. Third-stage larvae lacked both a boring tooth and lips. Fourth-stage larvae had well-developed lips. The ratio of ventricular appendage length to intestinal caecum length varied greatly between larval stages and adults. Prevalence and intensity of larval stages and adult H. analarum showed a distinct seasonal pattern, with one generation of adult worms per year. In spring, third-stage larvae left nodules on the intestinal serosa of L. gibbosus and migrated to the intestinal lumen, where they rapidly moulted to the fourth-stage and then to adult worms. Eggs collected from gravid females developed to second stage larvae in approximately 5 days under laboratory conditions. In natural infections in the late summer second-stage larvae were found in nodules on the serosa and in the mesentery. Larvae apparently moulted to the third stage and overwintered in the nodules as third-stage larvae.

scholarly journals Fatal Cytauxzoonosis in a Captive-reared White Tiger (Panthera tigris)

1996 ◽  
Vol 33 (1) ◽  
pp. 82-86 ◽  
Author(s):  
M. M. Garner ◽  
N. P. Lung ◽  
S. Citino ◽  
E. C. Greiner ◽  
J. W. Harvey ◽  
...  
Keyword(s):  
Developmental Stages ◽  
Severe Thrombocytopenia ◽  
Panthera Tigris ◽  
Domestic Cats ◽  
Mild Anemia ◽  
Large Numbers ◽  
Cytauxzoon Felis ◽  
History Of ◽  
White Tiger ◽  
Histologic Changes

Fatal (Panthera tigris) cytauxzoonosis was diagnosed in a 7-year-old female white tiger. The tiger presented with a 2-day history of anorexia and lethargy. She was mildly dehydrated, with a temperature of 105.2 F and a hematocrit of 26%. Over the next day, icterus developed, and her physical condition progressed to recumbency, coma, and death. Hematologic findings obtained shortly before death included icteric plasma, severe thrombocytopenia, mild anemia, hematuria, and parasites consistent with Cytauxzoon felis in circulating erythrocytes. Gross necropsy findings included generalized icterus, generalized petechiae and ecchymoses, splenomegaly, and peribronchial edema. Histologic changes included large numbers of intravascular macrophages containing developmental stages of Cytauxzoon felis that partially or completely occluded blood vessels in the lung, spleen, liver, and bone marrow. Except for an experimental infection of a bobcat, fatal cytauxzoonosis has not previously been diagnosed in felids other than domestic cats. These findings raise questions regarding the pathogenicity of this organism in felids and may impact husbandry and interstate transfer of captive large cats.

The developmental history of Mutela bourguignati (Ancey) Bourguignat (Mollusca: Bivalvia)

1961 ◽  
Vol 244 (711) ◽  
pp. 259-298 ◽  
Keyword(s):  
Ventral Surface ◽  
Main Body ◽  
South American ◽  
Freshwater Bivalve ◽  
Byssus Thread ◽  
Larval Stages ◽  
Large Numbers ◽  
History Of ◽  
And Function ◽  
First Time

An account is given for the first time of the development of Mutela bourguignati (Ancey) Bourguignat, an African freshwater bivalve of the family Mutelidae. Eggs are shed in large numbers into the inner demibranchs. There they develop into minute larvae similar in some respects to the lasidium larvae of certain South American freshwater mussels, but differing in several ways. Each larva consists of a rounded body covered dorsally and laterally by a thin pellicle and provided anteriorly with two lobes clothed with cilia. Posteriorly, and on the ventral surface, are two sets of minute hooks. Anteriorly is a remarkable elongate, flaccid and colourless tentacle more than seventy times as long as the larva itself. There is no gut, nor can endodermal or mesodermal tissues be recognized as such at this stage. After liberation via the exhalant siphon these larvae settle on the cyprinid fish Barbus altianalis radcliffi and there metamorphose and begin a parasitic phase of development. The larval pellicle folds, and its opposed edges fuse so as completely to enclose the larva. Two tubular outgrowths grow from its anterior end into the superficial tissues of the fish and serve both as organs of attachment and nutrition. In their vicinity skeletal tissues of the host are broken down. The main body of the larva, now designated the haustorial larva, elongates and becomes differentiated into a stalk and a bud. The stalk protrudes from the fish and bears the bud clear of the host. Within the bud the adult bivalve eventually develops. The stalk is traversed by long prolongations of the mantle which run into the haustorial tubes and function as absorptive tissues. The cuticle is not calcified nor is it composed of conchiolin. As differentiation proceeds the definitive mantle, which is the lineal descendant of the larval mantle, begins to secrete first periostracum then calcareous matter to form the rudiments of the valves, and a rudiment of the ligament is also formed. As adult features gradually appear the bud is burst and a young bivalve, little more than 1 mm in length, attached to a long stalk emerges. Independent, particulate feeding commences at this stage. Rupture of both cuticular and mantle elements eventually takes place at the point of juncture of stalk and young bivalve and the latter falls away to begin an independent existence. At the time of release it is capable of active locomotion and is able to produce a slender byssus thread. A detailed, illustrated account of these changes, both external and internal, is given, and the development of certain individual organs is traced. The nature of the cuticle of the haustorial larva, the effect of this larva on its host, and the affinities and probable evolution of the larval stages are discussed, and the importance of taking larval development into account in classification is emphasized.

Regulation ofAnguillicola crassus(Nematoda) infrapopulations in their definitive host, the European eel,Anguilla anguilla

Parasitology ◽  
2008 ◽  
Vol 135 (14) ◽  
pp. 1707-1716 ◽  
Author(s):  
G. FAZIO ◽  
P. SASAL ◽  
C. DA SILVA ◽  
B. FUMET ◽  
J. BOISSIER ◽  
...  
Keyword(s):  
Developmental Stages ◽  
Anguilla Anguilla ◽  
The Body ◽  
European Eel ◽  
Swim Bladder ◽  
Experimental Conditions ◽  
Larval Stages ◽  
Resource Limited ◽  
Third Stage ◽  
Opposite Sex

SUMMARYThe parasitic nematodeAnguillicola crassuswas recently introduced into populations of the European eel,Anguilla anguilla. We investigated, under experimental conditions, the regulation ofA. crassusinfrapopulations. We tested the effects of (1) the resource-limited habitat of the parasite and (2) the coexistence of several developmental stages in its niche (the swim-bladder) on the composition of the infrapopulations. The results revealed that the respective effects of these factors differed substantially during the course of the infection. Third-stage larvae (L3s) establishment would not be constrained by the size of the swim-bladder. Their moult to fourth-stage larvae (L4s) would be accelerated as the number of L3s increased. The moulting time of L4s to adults would be reduced by males and would be constrained by the size of the swim-bladder. However, the moult of L4s to adults and their further development would be synchronized with those of the opposite sex. At the time of mating, the number of males and the body weight of adults would depend on the size of the swim-bladder. Soon after the laying of eggs, the developmental constraint on the late L3s would decrease. When adults die, constraints would cease and late larval stages would moult to become adults.

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