scholarly journals Life History of the Camelthorn Gall Leafhopper,Scenergates viridis(Vilbaste) (Hemiptera, Cicadellidae)

2012 ◽  
Vol 2012 ◽  
pp. 1-19 ◽  
Author(s):  
Roman Rakitov ◽  
Esther Appel
Keyword(s):  
Life History ◽  
Subsequent Development ◽  
Adult Males ◽  
Sticky Traps ◽  
First Instar ◽  
Inner Surface ◽  
Two Generations ◽  
Young Leaves ◽  
History Of

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).

scholarly journals Life history of the gall-maker Eugeniamyia dispar Maia, Mendonça-Jr. & Romanowski, 1996 (Diptera, Cecidomyiidae)

2002 ◽  
Vol 62 (2) ◽  
pp. 277-283 ◽  
Author(s):  
M. de S.,Jr. MENDONÇA ◽  
H. P. ROMANOWSKI
Keyword(s):  
Life History ◽  
Host Plant ◽  
Urban Area ◽  
Porto Alegre ◽  
Eugenia Uniflora ◽  
First Instar ◽  
Young Leaves ◽  
History Of

The development of the galls of the midge Eugeniamyia dispar Maia, Mendonça-Jr. & Romanowski, 1996 (Diptera: Cecidomyiidae) was monitored weekly on its host plant, Eugenia uniflora (Myrtaceae). The work was carried out in the urban area of Porto Alegre, RS, Brazil, from October 1993 to September 1995. Galls were collected from the field and raised in the laboratory to obtain adults. The females oviposit on young leaves of the host plant, with the first instar larvae inducing the gall, which is unilocular. The last instar larvae drop to the soil to pupate and later emerge as adults. The galls occur from late August to early June, when young leaves of the host can be found, with populations peaking during the summer. So far this species is only known from the two southernmost states of Brazil (RS and SC).

On Crepidostomum farionis O. F. Müll. (= Stephanophiala laureata Zeder), a Distome Parasite of the Trout and Grayling. I. The Life History

Parasitology ◽  
1927 ◽  
Vol 19 (1) ◽  
pp. 86-99 ◽  
Author(s):  
F. J. Brown
Keyword(s):  
Life History ◽  
Gall Bladder ◽  
Excretory Vesicle ◽  
Intermediate Hosts ◽  
Larval Trematode ◽  
Sphaerium Corneum ◽  
Two Generations ◽  
History Of ◽  
Second Intermediate Host ◽  
Ephemera Danica

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.

scholarly journals On Apogamy and the development of Sporangia upon fern prothalli

1898 ◽  
Vol 63 (389-400) ◽  
pp. 56-61
Keyword(s):  
Life History ◽  
Point Of View ◽  
The Other ◽  
Normal Life ◽  
Other Hand ◽  
General Importance ◽  
Two Generations ◽  
History Of ◽  
Alternation Of Generations

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.

THE BIOLOGY OF PODISUS SERIEVENTRIS UHLER, IN CAPE BRETON, NOVA SCOTIA

1933 ◽  
Vol 9 (1) ◽  
pp. 1-30 ◽  
Author(s):  
M. L. Prebble
Keyword(s):  
Life History ◽  
Control Factor ◽  
Plant Food ◽  
Average Growth ◽  
Growth Ratio ◽  
Animal Food ◽  
Cape Breton ◽  
First Instar ◽  
History Of ◽  
June July

The biology of Podisus serieventris Uhler, and its role in an outbreak of the black-headed budworm, Peronea variana Fernald, in Cape Breton, N.S., are described from studies carried on in 1930 and 1931. There is but one complete generation of Podisus a year, and adults of both sexes hibernate. The eggs are laid in late June, July and early August, the incubation period ranging between 10 and 15 days. There are five nymphal stages, requiring about 45 days, on the average, for the attainment of the adult condition. In these respects particularly, the life history of Podisus serieventris in Cape Breton differs from its life history in Massachusetts, where four nymphal stages and three annual generations and the hibernation of females only, have been reported.The species conforms satisfactorily to Dyar's Law, the average growth ratio of individuals studied in 1931 being about 1.28. The first-stage nymphs feed on unhatched eggs of their own species, and upon the juices of coniferous and deciduous foliage, but were not induced to feed upon small caterpillars. Nymphs were able to complete the first instar on a purely vegetable diet, but died before the second moult when the same diet was continued. Older nymphs, fed for some time on animal food, were not able to attain the adult condition when supplied with plant food alone. This indicates the dependence of the species upon animal food; the food consumption of the various stages is briefly summarized. Evidence is presented which suggests the utilization, by Podisus, of a toxic secretion in overcoming their prey.The rather limited value of Podisus as a control factor in the outbreak of Peronea variana in 1930 and 1931 is described. The decline of the Peronea population in 1931 caused a corresponding mortality in the Podisus population, by starvation.

Habitat utilization by an intertidal isopod, Dynoides dentisinus Shen, 1929 (Isopoda, Sphaeromatidae)

Crustaceana ◽  
2019 ◽  
Vol 92 (2) ◽  
pp. 205-220 ◽  
Author(s):  
Takeru Nakamachi ◽  
Akira Asakura
Keyword(s):  
Life History ◽  
Habitat Utilization ◽  
Dorsal Side ◽  
Rocky Shores ◽  
Adult Males ◽  
History Of ◽  
Cryptic Habitats ◽  
Warm Temperate Zone ◽  
Cryptic Habitat ◽  
Living Objects

Abstract Intertidal isopods use a variety of living or non-living objects as habitats, although only a few studies have been made on their ecological function and significance. In the present study, the habitat utilization by the sphaeromatid isopod, Dynoides dentisinus was recorded based on observations on intertidal rocky shores in the warm temperate zone of Japan during the period from 2014 to 2018. The adults of this species have a remarkable sexual dimorphism in the morphology of their armature: adult males possess an elongate pleonal process, like a large horn, on the dorsal side of the pleon and have large uropods. On the other hand, females do not have such a horn, and the uropods are small. Differences in habitat use were seen according to the stage in the life history of the species. Juveniles lived on, or amongst, algae and were sometimes associated with molluscs such as chitons, limpets and whelks. Adults inhabited the cryptic habitats such as gaps in algal holdfasts, oscula of demosponges, dead barnacle shells, cavities of dead corals, and crevices in sand rocks. Generally, a single adult male was present in each cryptic habitat, keeping head in down position, and one or more females cohabited inside with the male. These suggest that D. dentisinus has a biphasic life history; juveniles live and feed on algal cover or use the spaces between the ventral sides of the molluscs and the surfaces of the rocks as a refuge from desiccation. Adults breed in the cryptic habitats, forming a polygynous group.

The life history of Caurinus dectes Russell, with a description of the immature stages (Mecoptera: Boreidae)

1982 ◽  
Vol 13 (2) ◽  
pp. 225-235 ◽  
Author(s):  
Loren K. Russell
Keyword(s):  
Life History ◽  
Antennal Segment ◽  
Seasonal Occurrence ◽  
Immature Stages ◽  
Larval Instars ◽  
Egg Diapause ◽  
First Instar ◽  
History Of ◽  
Thoracic Legs

AbstractThe egg, larva, and pupa of Caurinus dectes are described and illustrated. Eggs are ellipsoidal, coated with black cement, and are attached to bryophytes. The larva is orthosomatic, with much-reduced thoracic legs, and further differs from other larval Boreidae in: amphipneustic spiracles, number of stemmata (7), placoid sensilla present in membrane of first antennal segment, and egg burster on frons in first instar. Three larval instars are recognized from analysis of head measurements and partial rearing. Larvae feed in stemmines or galleries in leafy liverworts (Jungermanniales). Pupation occurs in a silk-lined cell or cocoon, otherwise unknown in the Mecoptera; the pupa is exarate, with decticous mandibles. The seasonal occurrence of egg eclosion (February-March), pupation (July-August), and principal adult activity (October-April) is typical for the Boreidae, but only C. dectes is univoltine in this family. Successive annual generations appear to overlap through extended egg diapause and adult perenniation.

The ecology of the swede midge, Contarinia nasturtii (Kieff.) (Diptera, Cecidomyiidae). I.—Life-history and influence of temperature and moisture on development

1966 ◽  
Vol 56 (4) ◽  
pp. 685-700 ◽  
Author(s):  
J. L. Readshaw
Keyword(s):  
Life History ◽  
Day Length ◽  
Influence Of Temperature ◽  
Young Leaves ◽  
History Of ◽  
Dry Soil ◽  
Diapause Development ◽  
First Time ◽  
Case Development ◽  
Contarinia Nasturtii

The life-history of Contarinia nasturtii (Kieff.), a gall-forming pest of swedes, was investigated in northern England in 1958–60, particular attention being paid to the influence of temperature and moisture on development in the soil. Most of the observations were made under controlled conditions in the laboratory, although much of the material came from the field.The adults emerge from the soil, mate, and live 1–3 days. In laboratory conditions, each female developed about 95 eggs, laid in batches of 2–50 on the young leaves of the host plant, and produced 78·7±11·4 unisexual larval progeny. The eggs require moist conditions, and hatched according to temperature after 1–10 days at 30–10°C. The larvae fed for 7–21 days at 25–15°C., producing a gall.The full-grown larvae burrow into the soil. It was found that they either pupated in oval-shaped cocoons just below the surface, producing adults 10–48 days later (at 25–12°C.) or become dormant in spherical cocoons. At 32·5°C. the pupae died, and below 32·5°C. males developed faster than females by about 24 hours.Dormancy is caused either by diapause, in which case the larvae require prolonged chilling before development can be resumed, or by drought, in which case development is resumed immediately in response to wetting.The incidence of diapause increased regularly during the summer generations, probably in response to decreasing day-length, and the larvae tended to avoid diapause when placed in high temperatures (e.g., 25°C.). The firmness of diapause appeared to vary according to the conditions experienced by the feeding and full-grown larvae, but, in general, the larvae completed diapause development after 100 days at 2–5°C. followed by 30 days at 20–25°C., i.e., after exposure to conditions similar to those experienced by the diapause larvae during winter and spring.Dormancy due to drought (quiescence) affected both non-diapause and post-diapause larvae; the former became quiescent on entering dry soil (pF>3·5–4·0), and the latter remained inactive if kept in dry or even in moist soil (pF 3·4) after completing diapause. In both cases, the termination of dormancy occurred immediately in response to a thorough wetting of the soil. The larvae left their spherical cocoons, moved to the surface, re-entered the ground and pupated in oval cocoons as if entering the soil for the first time.Factors that delay pupation of C. nasturtii similarly delay the development of its Hymenopterous parasites and hence synchronise the emergence of the adult parasites with the host's feeding stage.

NOTES ON THE OVIPOSITION AND LIFE HISTORY OF PHLEPSIUS DECORUS O. & B. (CICADELLIDAE)

1936 ◽  
Vol 68 (12) ◽  
pp. 280-281
Author(s):  
Ralph B. Swain
Keyword(s):  
Life History ◽  
Single Female ◽  
Sunflower Plant ◽  
Terminal Bud ◽  
Young Leaves ◽  
History Of

The writer is not aware that observations on the exceedingly interesting oviposition habits of Phlepsius decorus O. & B. have ever been published. A single female of this species was captured on a sunflower plant at Webster Groves, Mo., June 30, 1933. It was placed in a celluloid, cylinder cage enclosing the terminal bud and young leaves of a half-grown sunflower plant where it began feeding at once.

On the Morphology and Life History of Aproctonema entomophagum Keilin, a Nematode Parasite in the Larvae of Sciara pullula Winn. (Diptera—Nematocera)

Parasitology ◽  
1933 ◽  
Vol 25 (3) ◽  
pp. 285-295 ◽  
Author(s):  
D. Keilin ◽  
V. C. Robinson
Keyword(s):  
Life History ◽  
Systematic Position ◽  
Egg Laying ◽  
Nematode Parasite ◽  
Free Living ◽  
The Family ◽  
Two Generations ◽  
History Of ◽  
Decaying Wood

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.

LIFE HISTORY OF PLUTELLA PORRECTELLA, A RELATIVE OF THE DIAMONDBACK MOTH, PLUTELLA XYLOSTELLA (LEPIDOPTERA: PLUTELLIDAE)

1984 ◽  
Vol 116 (7) ◽  
pp. 913-917 ◽  
Author(s):  
D. B. Smith ◽  
M. K. Sears
Keyword(s):  
Life History ◽  
Plutella Xylostella ◽  
Diamondback Moth ◽  
Parasitic Wasp ◽  
Instar Larva ◽  
Alternative Host ◽  
Apical Buds ◽  
Two Generations ◽  
History Of ◽  
Early Instar

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.

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