Effect of temperature on the neurosecretory activity inNezara viridula Linn. (Heteroptera; pentatomidae)

Zusammenfassung Die neurosekretorischen Zellen und die davon ausgehenden Nerven vonNezara viridula Linn enthalten bei Zucht in niedriger Temperatur bedeutend weniger Neurosekret als in Normaltemperatur.     

Chromosome numbers inNabis Lt. (heteroptera,nabidae)

Zusammenfassung 9 Arten der GattungNabis Lt. wurden während der Spermatogenese in den Teilungsstadien karyologisch geprüft und ihre Chromosomenzahl bestimmt. Die charakteristische Grundzahl der Chromosomengarnitur wurde mit 16A+X+Y gefunden, wobei wenige Individuen mit überzähligem Geschlechtschromosom festgestellt werden konnten.     

Chromosome studies inSalvia (labiatae): West-himalayan species

Résumé Détermination de nombres chromosomiques dans des Sauges(Salvia) encore non étudiés du Himalaya.     

Chromosome complement of two species of Amelinae (Dictyoptera: Mantodea)

Summary The karyotypes ofApteromantis aptera (Fuente) andAmeles decolor (Charpentier) are described. Chromosomes numbers in females are 2n=30 and 2n=28 respectively. Sex determination mechanism in both is XO-XX.     

Chromosome complements of three species of Mugilidae (Pisces,Perciformes)

Riassunto Sono stati determinati i numeri diploidi di tre specie di Mugilidi:Mugil cephalus, Liza ramada eChelon labrosus. La morfologia del cariotipo diMugil cephalus mostra 24 coppie di piccoli cromosomi acrocentrici; nel cariotipo diLiza ramada e diChelon labrosus fa invece spicco, tra gli acrocentri, una coppia di subtelocentrici. Il dato cariologico è discusso in rapporto al problema della collocazione sistematica dei Mugilidae ed alla revisione del genereMugil, Linneo.     

Centromere nature of the chromosomes ofRanatra (Heteroptera)

Zusammenfassung Histologisch-cytologische Untersuchungen zeigen, dass die Chromosomen vonRanatra monozentrisch sind. Der Befund steht im Gegensatz zu Ergebnissen anderer Autoren an andern Heteroptera-Arten, die polyzentrische Chromosomen haben. Die Natur des Centromers ist also bei verschiedenen Arten der Heteropteren verschieden.     

Photoperiodic summation is temperature-dependent inPyrrhocoris apterus (L.) (Heteroptera)

Summary InPyrrhocoris apterus, a low temperature, 15°C, prevented the termination of diapause by long days and, unexpectedly, also the induction of diapause by short days. Both responses were enabled at a higher temperature, 26°C. In contrast to current concepts, it was proved that the summation of photoperiodic signals was temperature-dependent, since the morphogenetic development was prevented by starvation.     

Instar-specific defensive secretions of stink bugs (Heteroptera: Pentatomidae)

Defensive secretions (allomones) from first-instar nymphs of stink bugs in the subfamily Pentatominae contain (E)-4-oxo-2-decenal as a major constituent, whereas this compound is absent from later instars. In contrast, first instars ofEdessa meditabunda (Edessinae) produce allomones like those of later instars. The C₆ and C₈ (E)-4-oxo-2-alkenals are common, characteristic exocrine compounds of nymphal and adult Heteroptera, but (E)-4-oxo-2-decenal is previously unknown as a major natural product for which a biological role has yet to be established.     

Pulse-train synchronous pair-stridulation by maleSigara striata (Heteroptera,Corixidae)

Summary Two by two, stridulating males ofSigara striata are able to synchronize the time structure of their calls (pulsetrain synchronous stridulation).Supported by Deutsche Forschungsgemeinschaft, SFB 4 Regensburg.     

Chromosome mechanism inPolididus armatissimus (Reduviidae-Heteroptera)

Résumé Le nombre diploïde des chromosomes duPolididus armatissimus est de 14. L'X et l'Y sont de taille presque égale. L'ensemble des chromosomes de cette espèce représente un karyotype primitif pour la famille des Reduviidae.     

Amino acid requirements of the bugDysdercus similis freeman (hemiptera: Heteroptera)

Summary The amino acid requirements for moulting, growth and development ofDysdercus similis have been investigated. The insects could not moult and reach maturity when given 10 essential amino acids only. However, if these were supplemented either with glutamic acid, glycine or aspartic acid growth and moulting was found to be normal.Dysdercus has an unusual synthetic mechanism for converting tyrosine into phenylalanine.The author is grateful to Prof.R. S. Saini for his guidance, critical discussions and encouragement.     

3-Methyl-2-hexanone from the triatomine bugDipetalogaster maximus (Uhler) (Heteroptera; Reduviidae)

Summary The occurrence of 3-methyl-2-hexanone as a major component of the secretion and possible alarm substance from the metasternal scent glands in the triatomine bugDipetalogaster maximus is reported.The authors are indebted to Mr B.O.C. Gardiner of the Zoology Department, Cambridge, for a supply of livingDipetalogaster. They would like also to thank Dr D.E. Games for the provision of mass spectral facilities under support from the S.E.R.C.     

Chromosome polymorphism in deer mouse siblings (Peromyscus maniculatus)

Zusammenfassung Früher wurde bereits ein Chromosomenpolymorphismus in nicht verwandtenPeromyscus maniculatus, wahrscheinlich durch perizentrische Inversion bedingt, gezeigt. Es wird nun nachgewiesen, dass dieser Polymorphismus auch unter Geschwistern vorkommt.