Evolutionary scenarios for unusual attachment devices of Phasmatodea and Mantophasmatodea (Insecta)

Abstract.  The distal parts of the legs of representatives of Phasmatodea and Mantophasmatodea were examined. The condition found in Mantophasma zephyra and Timema nevadense is described in detail. In both species the arolium is highly modified, i.e. strongly enlarged and pan-shaped and densely covered with acanthae. The presence of acanthae on the euplantulae is another very unusual feature shared by the two taxa. A cladistic analysis based mainly on a data matrix from an earlier study of the authors was carried out, with the inclusion of three new characters derived from attachment devices. The results suggest three possible evolutionary scenarios for the features in question. If Phasmatodea are the sister group of Mantophasmatodea, the apomorphic features of the attachment devices may be synapomorphies of both groups, with different degrees of reversal within the suborder Euphasmatodea. A branching pattern Phasmatodea + (Mantophasmatodea + Grylloblattodea) is consistent with the presence of an enlarged pan-shaped arolium and euplantulae with acanthae in the common ancestor of this lineage, with reversal in Grylloblattodea and within Euphasmatodea. The acanthae on the surface of the arolium may or may not have evolved independently in Timema . A placement of Phasmatodea as sister taxon of Orthoptera, Dictyoptera, or a clade comprising both groups implies that the features in question have evolved independently in phasmids and Mantophasmatodea.     

Is Crowsoniella relicta really a cucujiform beetle?

Crowsoniella relicta Pace, one of the most obscure and cryptic beetle taxa, was recently transferred from Archostemata to the polyphagan series Cucujiformia. We discuss the arguments in favour of this hypothesis. The placement of the species is evaluated with a cladistic approach and two different morphological data sets: one aiming mainly to clarify the relationships of extinct and extant archostematans, and one aimed at resolving species‐level phylogeny for the suborder. The results suggest clearly that a position of Crowsoniella within a polyphagan subgroup is very unlikely, and that a placement in Archostemata is justified and should be maintained. Due to the serious lack of anatomical information, non‐destructive µ‐CT scanning of enigmatic taxa like Crowsoniella Pace and Sikhotealinia Lafer should have high priority.     

On the homology of the scales in Gunnera (Gunneraceae)

In the genus Gunnera , the species of subgenus Panke are unique in having large, triangular scales between the leaves on the rhizomes. The morphological significance of these scales has been extensively debated in the past. They have been interpreted as stipules, ligules, or cataphylls, with attempts made to identify homologous structures in representatives of the other subgenera. In the stoloniferous subgenus Misandra, the shoot apex is covered by a hoodlike structure, usually termed ochrea, generally considered homologous to the scales in Panke . Efforts to find similar structures in the remaining subgenera were unsuccessful. Due to the lack of a phylogenetic hypothesis, the homology of the scales has remained unresolved. In this study, the shoot apices of species from all subgenera were examined by light and scanning electron microscopy and the results interpreted in a phylogenetic context. The tip of the stolons in subgenera Pseudogunnera and Milligania carries two opposite cataphylls at the base of the new shoot. These are homologous to the ochrea in Misandra which is in turn homologous to the scales in Panke ; the latter are thus neither stipules nor ligules but cataphylls. The stems of subgenera Ostenigunnera and Gunnera have no similar structures. © 2003 The Linnean Society of London, Botanical Journal of the Linnean Society, 2003, 142 , 301−308.     

Preliminary characterization of glycogen phosphorylase activating hormone and adipokinetic hormone from Manduca sexta corpora cardiaca

ABSTRACT. An attempt was made to separate glycogen phosphorylase activating hormone (GPAH) and adipokinetic hormone (AKH) from the corpora cardiaca (CC) of the moth Manduca sexta (Lepidoptera: Sphingidae) by separating extracts of CC on various chromotographic media, but it was not possible to conclude whether GPAH and AKH are activities of one or of two different peptides. Both activities elute together from glass beads, from Sephadex G-25 and from Sephadex LH-20 columns. In the separation experiments with glass beads and G-25 the activities eluted as a single peak, but using LH-20 we found two peaks exhibiting both activities. The major peak eluted at 1.25 × V_t, which is very similar to locust AKH, while the smaller second peak eluted at O.74 × V _t. Cross injections of CC extracts from M. sexta into Locusta migratoria and CC extracts from L. migratoria into M. sexta suggest that GPAH and the AKH from M. sexta are not identical with the decapeptide AKH from locusts.     

Aromatic Substances in Leaves of Populus tremula as Inhibitors of Mycorrhizal Fungi

The inhibitory principles of aqueous extracts of aspen leaves, acting upon mycorrhizal fungi of forest trees, were isolated by extraction with ethyl acetate and chromatography on silicic acid. Two inhibitors were identified as benzoic acid and catechol by gas chromatography and mass spectrometry. When added to a synthetic medium, these substances had a strong inhibitory effect on the growth of different Boletus-species and a weaker inhibitory effect on litter-decomposing Marasmius-species. When the fraction of the extract which was not soluble in ethyl acetate was included in the medium, the aromatic compounds still inhibited the mycorrhizal fungi while the growth of the litter-decomposers was stimulated.     

Maternal-Fetal Oxygen Transfer in Lower Vertebrates

There exists a difference in oxygen affinity between fetal andmaternal bloods in almost all vertebrates examined and thisdifference in affinities probably facilitates oxygen transferto the fetus. It is likely that the high oxygen affinity offetal blood represents a biochemical pre-adaptation from anancestral oviparous embryo for oxygen uptake in a relativelyhypoxic environment. In most cases, the maternal-fetal differencein blood oxygen affinities is due to the characteristics ofthe fetal red cell and not due to any changes in the adult redcell during pregnancy. These characteristics are based on thepresence of a unique fetal hemoglobin with an intrinsicallyhigh affinity for oxygen or on the absence of high red cellconcentrations of organic phosphates—allosteric modulatorsof hemoglobin function. However, in several species of snake,representing different families, it appears that pregnancy isassociated with apronounced decrease in the oxygen affinityof the adult red cell. This suggests that the blood of the pregnantfemale is better able to unload oxygen to the fetus than couldthe blood of thenonpregnant adult. The maternal-fetal differencein blood oxygen affinities in these species isprobably due tothe characteristics of the fetal red cell as well as to thechange in the affinity of the adult cell during pregnancy. Nonetheless,although the magnitude of the pregnancy-associated change inoxygen affinity of the adult cell in these snakes suggests thatit is physiologically significant, the actual significance remainsto be determined.     

Fly on the wall – attachment structures in lower Diptera

Pretarsal attachment structures of representatives of the megadiverse Diptera are examined and documented, mainly using scanning electron microscopy. The focus is on the basal ‘nematoceran’ lineages. The diversity in structures is much higher than suggested by brief summarizing accounts in earlier studies. Both hairy and smooth attachment structures occur. A well‐developed, pad‐like empodium with its ventral surface covered with adhesive hairs is arguably a groundplan feature of Diptera. Very often this pad is combined with the presence of hairy pulvilli. However, smooth pulvilli occur in two of the examined groups. A smooth arolium is present in Tipulomorpha and likely an autapomorphy of this clade, suggesting that it was acquired secondarily. Evolutionary transformations are interpreted based on recently published dipteran phylogenies.     

Anomalous Effects of Heterologous Normal Serum on Interferon Production in Mice

WHILE studying the inhibitory effect of burro anti-mouse lymphocyte serum on the production of interferon in mice¹, we investigated whether rabbit anti-mouse lymphocyte serum (ALS) had similar activity. There was some inhibition of interferon production after intraperitoneal injection of polyinosinic/polycytidylic acid (poly IC) in NIH Swiss strain mice pretreated with three doses of potent rabbit anti-mouse lymphocyte serum. Animals treated with normal rabbit serum, however, showed a similar inhibition of interferon production (Table 1), although normal burro serum had no effect¹.