Entwicklung der Symbiontenorgane einer Kleinzikade (Euscelis plebejus Fall.) nach Ausschaltung der Symbionten

Summary Embryos of the leafhopperEuscelis plebejus Fall. deprived of their intracellular symbionts are known to develop larval mycetomes of apparently normal topography late in embryogenesis. New experiments indicate that even the provisional mycetome preceding the larval structure is formed during early development of asymbiotic eggs.     

Aseptic rearing of the aster leafhopper,Macrosteles fascifrons (Stål), on a chemically defined diet

Summary The normal symbiotic aster leafhoppers,Macrosteles fascifrons, were reared under aseptic conditions on the holidic diet through 5 successive generations with normal rates of development, survival and reproduction. Thus the artificial diet is completely adequate for normal insects and dependence on gut organisms is not part of the physiology of this species.     

The effect of leafhopper infestation on the respiration of castor bean varieties in relation to their resistance toEmpoasca flavescens (F.) (Homoptera: Jassidae)

Zusammenfassung Die Saugtätigkeit der JassideEmpoasca flavescens (F.) führte zu einer um 44% gesteigerten Respiration von geschädigten, anfälligen Rizinuspflanzen (Ricinus communis L.) im Vergleich zu 11.6% und 3.7% bei Pflanzen einer toleranten und resistenten Sorte. Diese Zunahme war bei der anfälligen Sorte verknüpft mit einer gesteigerten Anhäufung von Rohrzucker, Gesamtstickstoff und Gesamtaminosäuregehalt.

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This study formed part of the Doctoral Thesis submitted to the University of Madras and financial support was given by the Council of Scientific and Industrial Research, Government of India, New Delhi. Grateful appreciation is extended to Prof. A. R.Seshadri, Agricultural College and Research Institute, Coimbatore, India and Prof. R. H.Painter, Kansas State University, Kansas, U.S.A. for their valuable suggestions made during the course of the study.     

On the multiple sex chromosome mechanism in a lygaeid,Oxycarenus hyalinipennis (Costa)

Résumé Oxycarenus hyalinipennis (Costa) possède vraisemblablement des chromosomes sexuels multiples du typeX ₁ X ₂ Y. Les métaphases diploïdes renferment, soit 17, soit 19 éléments. Les 2 éléments supplémentaires des cinèses à 19, bien que comparables auxm-chromosomes des autres Lygéides, diffèrent de ces derniers en certains points de leur comportement qui évoque celui des «surnuméraires» trouvés chez d'autres insectes. La méiose est du type habituel chez les Hétéroptères.     

On the storage and mobilization of organic resources in the hepatopancreas of a crab (Paratelphusa hydrodromus)

Résumé Etude des changements cycliques observés dans les hydrates de carbone et les lipides contenus dans l'hépatopancreas du crabeParatelphusa hydrodromus pendant le cycle de mue.     

On the structure of the natural dipeptide N-acetyl-aspartyl-glutamic acid (NAAGA)

Riassunto Si descrive la sintesi dei due dipeptidi isomeri acido N-acetil--l-aspartil-l-glutammico (I) e acido N-acetil--l-aspartil-l-glutammico (II). Il loro confronto con il NAAGA, dipeptide precedentemente isolato dal tessuto nervoso di alcuni mammiferi, ha dimostrato l'identità del nuovo metabolita con il-dipeptide (II).     

On the lay-out of the midgut rudiment inLoligo pealei (LeSueur)

Zusammenfassung Die Abschnürung von Teilen des ungefurchten Eicortex in der prospektiven Mittel- und Enddarmregion beiLoligo pealei führt zum Fehlen der entsprechenden Darmteile in späteren Stadien. Dies zeigt, dass die zusammenhängenden Anlagen des Mittel- und Enddarmkomplexes von Anfang an in Form eines lateral weit ausladenden Epithelstreifens vorliegen.     

Interruption of acoustic communication and mating in a leafhopper and a planthopper by aerial sound vibrations picked up by plants

Summary Each sex of the cotton leafhopper and the rice brown planthopper communicates with the opposite sex by certain specific sound vibrations which travel through the plant surface and lead to mating. External sounds of certain frequencies, viz., 200 c/sec, generated by a harmonium or an audio-oscillator are picked up from the air by the plants and interrupt the acoustic communication as well as mating of the insects. Notes with harmonics are effective whereas pure notes are ineffective.The authors gratefully acknowledge P.L. 480 grant No. FG-IN-551 from the US Department of Agriculture for project No. IN-ARS-90, under which this work was carried out.     

On the existence of intermediate compounds between hemoglobin (wholly ferrous) and methemoglobin (wholly ferric)

Zusammenfassung Experimentelle Befunde vonDarling undRoughton wurden mathematisch mittels der stöchiometrischen Gleichung analysiert. Entgegen der Meinung jener Versuche sind der vorgenannten Gleichung nach in einer Lösung von Hämoglobin plus Methämoglobin (durch Ferrizyanid) nur Moleküle anwesend, deren vier Eisenatome alle in dem Ferro- bzw. in dem Ferrizustand sind.