Courtship behaviour in the genus Nomada – antennal grabbing and possible transfer of male secretions

Due to low population densities, copulation in the cuckoo bee genus Nomada has not previously been observed, although a seminal paper by Tengö and Bergström (1977) on the chemomimesis between these parasitic bees and their Andrena or Melitta hosts postulated that secretions from male glands might be sprayed onto females during copulation. Our observations on the initiation and insertion phase of copulation in three species of Nomada now indicate antennal grabbing as a mechanism by which chemicals are transferred between the sexes. Histological studies of the antennae of N.fucata and N.lathburiana reveal antennal modifications associated with cell aggregations that represent glandular cells, and SEM studies revealed numerous excretory canals.

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STUDIES OF PHYSIOLOGICALLY ACTIVE ARTHROPOD SECRETIONS: VI. EVIDENCE FOR A SEX PHEROMONE IN FEMALE ORGYIA LEUCOSTIGMA (LEPIDOPTERA: LYMANTRIDAE)

The Canadian Entomologist ◽

10.4039/ent103706-5 ◽

1971 ◽

Vol 103 (5) ◽

pp. 706-712 ◽

Cited By ~ 17

Author(s):

Miss J. E. Percy ◽

Miss E. J. Gardiner ◽

J. Weatherston

Keyword(s):

Sex Pheromone ◽

Sex Attractant ◽

Epidermal Cells ◽

Biologically Active ◽

Histological Studies ◽

Orgyia Leucostigma ◽

Glandular Cells ◽

Glass Tubes

AbstractThe results of behavioural, chemical, and histological studies are reported showing the presence of a sex attractant in female Orgyia leucostigma J. E. Smith. A method of bioassaying the attractancy of the female moths by the use of 4-ft-long glass tubes is given. Extraction of female abdominal tips with dichloromethane yields material biologically active when tested against male O. leucostigma.The pheromone-producing gland is a dorsally situated, crescent-shaped structure formed by modification of the epidermal cells in the intersegmental membrane between the eighth and ninth abdominal segments. The glandular cells are goblet-shaped and are arranged in an unusual manner.

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Ultrastructural Alterations in Sinusoidal Endothelial Fenestrae as a Result of Hypoxia

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100090828 ◽

1976 ◽

Vol 34 ◽

pp. 168-169

Author(s):

Waykin Nopanitaya ◽

Raeford E. Brown ◽

Joe W. Grisham ◽

Johnny L. Carson

Keyword(s):

Endothelial Cells ◽

Experimental Model ◽

Hepatic Lobule ◽

Ultrastructural Alterations ◽

Large Type ◽

Sinusoidal Endothelial Fenestrae ◽

General Size ◽

Sem Studies

Mammalian endothelial cells lining hepatic sinusoids have been found to be widely fenestrated. Previous SEM studies (1,2) have noted two general size catagories of fenestrations; large fenestrae were distributed randomly while the small type occurred in groups. These investigations also reported that large fenestrae were more numerous and larger in the endothelial cells at the afferent ends of sinusoids or around the portal areas, whereas small fenestrae were more numerous around the centrilobular portion of the hepatic lobule. It has been further suggested that under some physiologic conditions small fenestrae could fuse and subsequently become the large type, but this is, as yet, unproven.We have used a reproducible experimental model of hypoxia to study the ultrastructural alterations in sinusoidal endothelial fenestrations in order to investigate the origin of occurrence of large fenestrae.

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