Life history of Acanthoparyphium spinulosum Johnston, 1917 (Trematoda: Echinostomatidae).

1960 ◽  
Vol 8 (2) ◽  
pp. 217 ◽  
Author(s):  
AJ Bearup

A list is given of the trematode cercariae which are commonly found in the estuarine gastropod, Pyrazus australis Quoy & Gaimard. These include: cercariae of a schistosome, Austrobilharzia terrigalensis Johnston, 1917, and of a heterophyid, Stictodora sp.; a monostomate xiphidiocercaria, probably belonging to the Microphallidae; two megalurous cercariae, probably belonging to the Philophthalmidae; and one echinostome cercaria. The life history of the latter, Acanthoparyphium spinulosum Johnston, 1917, is described. No sporocysts were found. Two generations of rediae precede the cercariae, which have a collar with 23 spines in a single row, as in the adult. Cercariae encyst readily in Salinator fragilis (Lamarck), another gastropod living in the same habitat. Cysts were also found occasionally in P. australis and in small polychaetes of the Phanaerocephala group. Adults were obtained by feeding S. fragilis, which contained encysted cercariae, to the silver gull, Larus novae-hollandiae.


Parasitology ◽  
1927 ◽  
Vol 19 (1) ◽  
pp. 86-99 ◽  
Author(s):  
F. J. Brown

1. Crepidostomum farionis inhabits the gall bladder, as well as the intestine and pyloric caeca, of the trout and grayling.2. The life history of Crepidostomum farionis has been worked out and is based on the similarity of organisation of the cercaria, encysted larval trematode and the adult.3. The first intermediate hosts in the life history of this trematode are Pisidium amnicum (Müll.) and Sphaerium corneum (L.) though the latter is unusual.4. The second intermediate host is the larva of the mayfly, Ephemera danica (Müll.).5. There are two generations of rediae, the first gives rise to daughter rediae, which in turn produce cercariae.6. The rediae are characterised by the absence of ambulatory processes and a functional intestine.7. The cercaria (n.sp.) possesses “eye spots,” stylet and gland cells (salivary?), and the excretory vesicle is tube-shaped.8. The excretory system of the redia and the cercaria has been worked out in detail.9. The relation of the parasites to their respective hosts is discussed. On account of the need for further observations definite conclusions are held over for a later paper.



1898 ◽  
Vol 63 (389-400) ◽  
pp. 56-61

The two most important deviations from the normal life-history of ferns, apogamy and apospory, are of interest in themselves, but acquire a more general importance from the possibility that their study may throw light on the nature of alternation of generations in archegoniate plants. They have been considered from this point of view Pringsheim, and by those who, following him, regard the two generations as homologous with one another in the sense that the sporophyte arose by the gradual modification of individuals originally resemblin the sexual plant. Celakovsky and Bower, on the other hand, maintaint the view tha t the sporophyte, as an interpolated stage in the life-history arising by elaboration of the zygote, a few thallophytes.



1904 ◽  
Vol 36 (4) ◽  
pp. 103-106
Author(s):  
Otto Seifert

On April 24th two ♀ ♀ of this month were found resting on the ground within a cluster of Sumach-brush, at Wooside, Long Island, N. Y. Their bright yellow colour had faded to pale ochre.Eggs were deposited from April 24th to 28th, only during the night. According to circumstances they are secreted within the fissures of the leaf-buds and narrow crevices of bark, or into the folds of decaying leaves of the food-plant. In the first case the nearly elliptical eggs are fgastened erect, close together, in a single row; when attached to a broader surface they are arranged in small regular patches or rows, but deposited lengthwide, the next one always overlapping the preceding one with its, blunt, micropylar end.



Parasitology ◽  
1933 ◽  
Vol 25 (3) ◽  
pp. 285-295 ◽  
Author(s):  
D. Keilin ◽  
V. C. Robinson

1. An account is given of Aproctonema entomophagum Keilin 1917, a Nematode parasite of the larvae of a Mycetophilid fly, Sciara pullula Winn., inhabiting decaying wood.2. The life history of this parasite is remarkable in the following respects:(a) The free-living stage is very short.(b) Both sexes are parasitic.(c) The usual host is the larva of the fly, from which the parasite escapes by actively breaking through the skin; but some parasites may be carried through to the imagines, from which they escape largely by the aid of the egg-laying movements provoked by them in the flies.3. Metamorphosis of the Sciara larva is delayed by the parasitism, so that at least two generations of Nematodes may be found in one host.4. All the parasitised imagines so far examined have been females.5. The systematic position of Aproctonema is discussed, the conclusion being that this worm and its near relative, Tetradonema plicans Cobb 1919, represent two closely allied genera of the family Mermithidae, but are not synonymous with Mermis. It is proposed to dispense with the family Tetra-donematidae Cobb.



1984 ◽  
Vol 116 (7) ◽  
pp. 913-917 ◽  
Author(s):  
D. B. Smith ◽  
M. K. Sears

AbstractAlthough Plutella porrectella (L.) is similar in appearance to the diamondback moth, P. xylostella (L.), several aspects of its biology are quite different from its more common relative. P. porrectella completed two generations per year and overwintered as an early-instar larva within apical buds of dame's rocket, Hesperis matronalis (L.). Four instars were observed in larvae reared in the laboratory. An average of 30 days was required for completion of one generation at 25 °C. This species does not seem to be an alternative host for parasites of the diamondback moth as only a single parasitic wasp, Itoplectis conquisitor (Say), was reared from 228 larvae collected in the field.



2012 ◽  
Vol 2012 ◽  
pp. 1-19 ◽  
Author(s):  
Roman Rakitov ◽  
Esther Appel

The world’s only member of Hemiptera Auchenorrhyncha known to form true galls, the leafhopperScenergates viridis(Vilbaste) (Cicadellidae), transforms leaves of camelthorn (Alhagi maurorumMedikus, Fabaceae) into pod-like chambers, up to 35 mm long, inside which individual leafhoppers develop, mate, and lay eggs. At the study site 40 km SE of Bukhara (Uzbekistan), two generations develop annually. First-instar nymphs cause young leaves to fold along the midrib. The subsequent development takes place inside the tightly closed growing gall, plugged at both ends with a mixture of leafhopper excrement, brochosomes, and crushed exuviae. These plugs act as mechanical barriers and sticky traps for intruders. The inner surface of the gall, lined with brochosomes and wax platelets, is hydrophobic. Adult males emerge from their galls and squeeze into female galls. Fertilized females insert an average of 146 eggs under the gall’s inner epidermis and remain inside, possibly protecting the brood, until they die. The walls of the galls containing eggs are approximately three times thicker than regular leaves. The galls are subject to predation by Gelechiidae caterpillars; the eggs of the leafhopper are parasitized by two species of Trichogrammatidae and one Mymaridae (Hymenoptera), and its larvae by one species of Pipunculidae (Diptera).



1961 ◽  
Vol 93 (2) ◽  
pp. 101-106 ◽  
Author(s):  
J. P. Perron ◽  
J. Lafrance

The onion maggot, Hylemya antiqua (Meig), has three distinct generations a year in Canada (Armstrong 1924, Hammond 1924, Baker 1928, Lafrance and Perron 1959), and usually two generations in England (Miles 1955). In Canada the three generations overlap considerably and adults of each generation are observed in flight in late summer (Perron et al. 1953). It is the most important pest of onions (Matthewman et al. 1950, Hudon and Perron 1956), and the first generation is the most injurious to the onion plants (Kendall 1932, Miles 1953).



1978 ◽  
Vol 52 (1) ◽  
pp. 51-59 ◽  
Author(s):  
R. Madhavi

ABSTRACTThe life history of Allocreadium fasciatusi which occurs in the intestine of a freshwater fish Aplocheilus melastigma has been worked out in detail. The snail Amnicola travancorica acts as the first intermediate host. The miracidium hatching out from the eggs attacks the snail and passes through two generations of rediae. Cercariae are of ophthalmoxiphidiocercous type with very long tail and are identical to Cercariae Indicae XLIX Sewell, 1922. The cercariae penetrate and develop into metacercariae in the haemecoel of the copepods Mesocyclops leuckarti, Microcyclops varicans and Marcocyclops distructus. Upon ingestion by the definitive host, the metacercariae excyst and develop into adults. All the stages in the life cycle are described and the life cycle is compared with other allocreadiid life cycles. The original description of A. fasciatusi is revised and Psilostomum chilkai Chatterji, 1956 from Lates calcalifer is synonymized with it.



1979 ◽  
Vol 57 (4) ◽  
pp. 785-793 ◽  
Author(s):  
D. S. Pezzack ◽  
S. Corey

Neomysis americana in Passamaquoddy Bay produces two generations per year. Breeding occurs during the spring, summer, and early fall. Each female is capable of producing two or three broods; average brood sizes for spring and summer females were 45 and 32, respectively. Development time of eggs varied directly with temperature. The intermolt period of juveniles remained constant up to the time of the development of secondary sexual characteristics, between the eighth and ninth molts, and then increased. The life history of N. americana in Passamaquoddy Bay is compared with that in other areas.



2006 ◽  
Vol 96 (6) ◽  
pp. 613-618 ◽  
Author(s):  
A.A. Azidah ◽  
M. Sofian-Azirun


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