Occurrence of aldehyde-fuchsin and performic acid-victoria blue positive granules in the ovarian pedicle ofDysdercus koenigii F. (Pyrrhocridae: Heteroptera)

Summary A cycle of activity of aldehyde-fuchsin and performic acid-Victoria blue positive granules was observed in the ovarian pedicle ofDysdercus koenigii during the first ovipositional cycle. The quantitative variation of these granules in the pedicle can also be correlated directly with the increase or decrease of the neurosecretory material in the A-type cells of the pars intercerebralis medialis region of the protocerebrum of the brain.The authors are grateful to Director of Research, University of Udaipur, Udaipur (Rajasthan), for providing laboratory facilities.     

Endocrine control of mating instinct in Dysdercus koenigii (Hemiptera: Pyrrhocoridae).

Five pairs of median and 1 pair of lateral neurosecretory cell groups occur in the protocerebrum of Dysdercus koenigii, a hemipteran pest on the ladies finger plant (Hibiscus esculentus). The lateral neurosecretory cells (LNSC) become active prior to, and at the time of commencement of mating and release their secretion within 24 h of commencement. The female never mates again after laying eggs and the LNSC also never become active. It is believed that LNSC secretion induces the urge for mating in the freshly emerged female and the lateral groups of NSC form the receptivity centre in the brain.     

On the contribution of haemolymph to the salivary proteins of the red cotton bug,Dysdercus koenigii F. (Heteroptera,Pyrrhocoridae)

Summary Polyacrylamide gel electrophoresis of haemolymph and the salivary gland of adult maleDysdercus koenigii has been carried out. The presence of common bands in the electropherograms of the salivary gland and haemolymph shows the possible elaboration of haemolymph protein into the salivary glands as also evidenced by leucomethylene blue incorporation into the salivary gland lobules. The results are discussed in the light of our present state of knowledge.I wish to acknowledge the financial support from the C.S.I.R., New Delhi, India. Grateful acknowledgements are made to Prof. P.S. Ramamurty for encouragements, and to Zoology Department, Banaras Hindu University for the working facilities.     

Observations on the neurosecretory axons in the aortal wall ofHalys dentatus F. (Heteroptera: Pentatomidae)

Zusammenfassung Neurosekretorisches Material kann in der Wand der Aorta eines Insekts nachgewiesen werden. Das Material befindet sich dort ausschliesslich in den sich verzweigenden Axonen der NS-Zellen.     

The use of F.S.H. gonadotrophins to obtain functioning ovarian grafts in the anterior chamber of the eye

Riassunto È stata studiata la possibilità di ottenere in camera anteriore innesti ovarici, sensibili all'azione di urina di donna gravida.È stato osservato che le gonadotropine F.S.H. favoriscono la crescita dell'ovaio innestato, mentre le gonadotropine L. H. non mostrano alcuna azione.Il preparato innestato in camera anteriore reagisce all'inoculazione di urina di donna gravida, mentre non è influenzato dall'inoculazione di urina di donna non gravida o di urina di uomo.     

Moult inhibition in the insectDysdercus cingulatus (Insecta: Heteroptera) by the cerebral glands of the millipedeJonespeltis splendidus (Myriapoda,Diplopoda)

Summary Implantation of 2 pairs of cerebral glands of the diplopodJonespeltis into the newly-moulted 4th or 5th instar nymphs of the insectDysdercus delayed the moulting of these insects for a fairly long time. Implantation of cerebral glands into 1-day old 5th instars postponed the subsequent moult for a shorter period, whereas implantation of cerebral glands into 2-day old 5th instars had no effect. These observations suggested that a neurosecretory factor from the cerebral glands inhibited moulting in this insect, and in the case of 5th instar nymphs there was a critical period before which implanted glands were effective in moult inhibition.Acknowledgments. Prof. V.K.K. Prabhu is thanked for suggesting the topic and for guidance. The University of Kerala is thanked for the fellowship awarded. The laboratory facilities afforded are also gratefully acknowledged.     

Karyotype and DNA content of Pharctolaemus ansorgei Blgr. (Teleostei: Gonorynchifomes).

The diploid DNA content of Pharctolaemus ansorgei spinosus (Phractolaemidae) is estimated by Feulgen cytophotometry at 3 pg. The karyotype has 28 chromosomes and 54 chromosome arms; it significantly resembles the karyotype of Chanos chanos (Chanidae).     

Composition and novel pattern of emission of defensive scent oils in the larva of the contton seed bugOxycarenus hyalinipennis (Costa) (Heteroptera: Lygaeidae)

Summary differences in composition and pattern of eiission in the scent oils from the two abdominal scent glands in the larva ofOxycarenus hyalinipennis are reported. The scent oils contain hex-2-enal, oct-2-enal, dec-2-enal and 4-oxo-oct-2-enal.We thank D. E. Games for access to mass spectral facilities, M. Rossiter for recording the mass spectra, the Bayero University Higher Degrees Committee for providing funds to T. O. Olagbemiro and PPF International for supply of sample materials.     

Slavery in the subfamily dolichoderinae (F. Formicidae) and its ecological consequences

Summary Evidence of slave-making habits in 2 species of the subfamily Dolichoderinae has been found in arid habitats of western North America. The enslaved species are of the subfamilies Myrmicinae and Formicinae. In previously reported cases of slavery in ants, both the slave-making and enslaved species are of the subfamily Formicinae., In the 2 new cases of slavery reported here, presence of slaves of another species in a colony significantly increases the breadth of diet and/or the range of temperatures at which the colony forages.     

In vitro protein synthesis and alpha amylase activity in F cells from hepatopancreas of Palaemon serratus (Crustacea; Decapoda).

In crustaceans, all the steps in the assimilation of food take place in the hepatopancreas. To facilitate the study of this organ, a method for the dissociation of cell types was developed. The hepatopancreas of the prawn Palaemon serratus was mechanically dissociated and the cells separated by Percoll density-gradient centrifugation. The E and R cells had similar densities of around 1.05 g/ml. The F cells were separated into two distinct fractions with densities of 1.075 and 1.082 g/ml. The B cells sedimented at a density of 1.12 g/ml. The ratio between the two populations of F cells was found to vary during the intermolt cycle while B cells disappeared after the molt. When the density gradient fractions were incubated with 3H-leucine, incorporation was highest in the F cell fractions. Measurements of alpha-amylase activity, indicated that the two populations of F cells may be derived from the same cell type.     

Dual activity of the pars intercerebralis of Panstrongylus megisturs (Heteroptera, Reduviidae) in the control of oogenesis and molting]

The action of A and A' cells of the pars intercerebralis of P. megistus on female gonial mitosis and meiosis is established experimentally by selective ablations and by implantations of brains devoid of their A cells. Molting is dependent on two factors originating in each neurosecretory cell type.     

Development of the electric discharge in mormyrid and gymnotid fish (Marcusenius sp. and Eigenmannia virescens).

Larvae of both species start discharging at 8 days. Eigenmannia immediately produces pulses similar to those of the adult. Marcusenius however, possesses a characteristic larval discharge 20 times longer and of opposite polarity to the adult discharge which appears on Day 40.     

Influence of host plant and larval diet on ovarian productivity inAcrolepiopsis assectella Z. (Lepidoptera: Acrolepiidae)

Summary Females ofAcrolepiopsis assectella, reared on a semi-synthetic diet and laying on artificial substrates, do not respond to external stimuli by increasing ovarian production. When returned to the natural host (Allium porrum) for only one generation, ovarian production again rises and reaches the same level as in wild females, but its variability is strongly reduced. We conclude that selection under artificial conditions eliminates individuals which strictly depend on host plants for stimulation of larval nutrition and of reproduction.     

Attraction ofScolytus scolytus (F.) to the components of Multilure,the aggregation pheromone ofS. multistriatus (Marsham) (Coleoptera: Scolytidae)

Summary The attraction ofS. scolytus to the components of Multilure is described. 4-Methyl-3-heptanol is an attractant which is synergised bya-cubebene. Multistriatin appears to be an inhibitor. A combination of 4-methyl-3-heptanol and cubeb oil is more effective as a bait forS. scolytus than Multilure.We thank Mr A. K. Hughes and Mr J. Boswell for their cooperation in allowing us to conduct experiments on Parham Estate; Mr D. Mobbs and Mr C. Thorne for the statistical analyses; Dr J. W. Peacock for samples of mixed isomers of multistriatin and distilled cubeb oil; Mrs J. Allsop and Mr N. J. Fielding for technical assistance. We are grateful to Mr D. Bevan, Dr J. H. Borden, Dr J. F. Grove and Prof. A. W. Johnson for their interest and encouragement.     

A synergistic interaction between the teratogenic effect of trypan blue and dietary deficiency in the rat.

There was an increased incidence, compared to controls, of exencephaly and microphthalmia in the offspring of rats fed a vitamin D deficient diet and injected with trypan blue on day 9 of gestation. Oral vitamin D did not reverse the effect.     

Lithium and rubidium: effects on the rhythmic swimming movement of jellyfish (Aurelia aurita).

The effects of adding LiCl, RbCl, KCl or NaCl to sea water at concentrations up to 30 mmoles/1 on the frequency of contraction of jellyfish (Aurelia aurita) suggest that studies on phylogenetically low animals with relatively simple nervous systems may be of use to determine mechanisms of action of lithium and rudidium on movements.