Short-winged (brachypterous) and long-winged (macropterous) adult females of Pyrrhocoris apterus (L.) originating from a Mediterranean population (Israel) were analyzed for their adipokinetic responses. The adipokinetic response, expressed as an increase of haemolymph lipids after injection of adipokinetic hormone from Locusta migratoria (Lom-AKH-I), was assessed in relation to age and dose of the hormone. We demonstrate in this study that the adipokinetic responses induced by bug's corpora cardiaca extract and Lom-AKH-I were dose-dependent for both brachypterous and macropterous females. Significant differences between the morphs were recorded for doses >= 0.25 corpora cardiaca equivalent (P < 0.01) and doses >= 0.25 pmol Lom-AKH-I (P < 0.05). The haemolymph lipid elevations induced in both morphs by 2 pmols Lom-AKH-I are comparable with that induced by crude extract of one pair of the bug's own corpora cardiaca. The age-dependent test showed much higher adipokinetic responses (P < 0.01) in macropterous females (>= 5 days old) than in the brachypterous females of the same age, when treated with 2 pmols Lom-AKH-I. Starting from day 7, the concentration of haemolymph lipids was also considerably higher (2.5-5 times) in macropterous females than in the brachypterous ones. The obtained data indicate that difference in mobilization of lipids between brachypterous and macropterous females is a geographically independent feature and represents a true wing morph characteristic of P. apterus., Dalibor Kodrík, Radomír Socha, and Lit
In cockroaches and certain other insects the concentration of trehalose in the hemolymph is increased by hypertrehalosemic hormone (HTH), a neuropeptide originating in the corpus cardiacum. A vital step in the action of HTH to promote conversion of glycogen stored in the fat body to trehalose is the activation of phosphorylase. The means by which HTH activates phosphorylase, with particular emphasis on its role in the regulation of intracellular calcium, is discussed. Additional information supporting the view that HTH stimulated synthesis of trehalose, and possibly its release from the trophocyte, is regulated by fatty acids and eicosanoids is presented., John E. Steele, and Lit
More than 60 neuropeptides that inhibit juvenile hormone synthesis by the corpora allata have been isolated from the brains of various insect species. Most of them are characterized by a common C-terminal pentapeptide sequence Y/FXFGL/I/V (allatostatin A family, allatostatin superfamily). Besides the allatostatin A family, allatostatic neuropeptides belonging to other two peptide families (W2W9)-allatostatins or allatostatin B family; lepidopteran allatostatin) were reported. So far, only one allatotropin has been identified. Here we discuss latest literature on the multiplicity and multifunctionality of the allatoregulating neuropeptides, their physiological significance as well as their evolutionary conservation in structure and function., Klaus H. Hoffmann, Martina Meyering-Vos, Matthias W. Lorenz, and Lit
Four peptides with allatostatic activity were isolated from brains of the Mediterranean field cricket, Gryllus bimaculatus. Three of them (Grb-AST A3: AGMYSFGL-NH2; Grb-AST A4: SRPFGFGL-NH2; Grb-AST A5: GPDHRFAFGL-NH2) belong to the wide-spread family of Y/FXFGL/I-amide peptides, the fourth (Grb-AST B5: AWDQLRPGW-NH2) is a member of the W2W9 - amide family of neuropeptides. All of these peptides are potent inhibitors of juvenile hormone (JH) biosynthesis by cricket corpora allata in vitro, causing 50% inhibition of JH biosynthesis at 0.4-3 × 10-8 M. The two peptides Grb-AST A5 and Grb-AST B5 have virtually the same potency and efficacy in inhibiting JH biosynthesis in vitro. No synergistic effect of the two peptide families with respect to the inhibition of JH biosynthesis could be observed. Peptides of both families decrease the accumulation of methylfarnesoate, the direct precursor of JH, within CA that have been incubated in farnesol-rich medium. This suggests an involvement of these ASTs in the late steps of JH biosynthesis., Mathias W., Roland Kellner, Klaus H. Hoffmann, and Lit
Allozyme polymorphism was investigated in adult males of the stenotopic peat bog (tyrphobiontic) noctuid moth, Coenophila subrosea Stephens, from three isolated peat bog localities in Austria (Styria) and Czech Republic (South and North Bohemia). Of the eighteen enzyme loci examined, twelve were polymorphic and six monomorphic. Significant deviations of genotype frequencies from Hardy-Weinberg equilibrium were observed at about one third of polymorphic loci within the populations. The average heterozygosities for the populations from three geographically distinct localities ranged from 0.192 to 0.245, and 61% of the loci were polymorphic. The FST mean value of 0.0675 was higher than that found in most other Lepidoptera. The genetic distances based on allozyme heterozygosity ranged from 0.019 to 0.051, with the population from South Bohemia being the most distant. The genetic distances and FST values do not reflect the geographic distances between the populations. Morphometric analysis revealed a difference between the Austrian Purgschachen Moor and Bohemian populations. These isolated relict peat bogs are habitat islands inhabited by unique "geographical races" of tyrphobiontic taxa., Jan Šula, Karel Spitzer, 4 obrázky, 5 tab., and Lit.
Emp-AKH is a member of the large adipokinetic hormone (AKH) family of peptides. This peptide family appears to occur in the corpora cardiaca of all insect species and its members are involved in regulating substrate mobilisation. The secondary structure of Emp-AKH has been studied in the presence of sodium dodecyl sulfate micelles by comparing data obtained from Nuclear Magnetic Resonance and molecular dynamics simulations. The lowest energy conformer obtained in this study has a turn consisting of residues 5-8 and a tail consisting of the first five residues., Igor Z. Zubrzycki, Gerd Gäde, and Lit
Female hybrids of the cross Chironomus t. thummi female × Ch. t. piger male which are largely affected by the sterility inducing Rud syndrome were backcrossed with males of both parental strains. The aim of the study was to provide information about those egg volumes that are insufficient for a normal embryogenesis and to ascertain whether in the hybrids the lethally small egg size represents a new abnormal trait of the Rud syndrome. The egg masses obtained contain eggs of very different sizes with volumes ranging from 0.5 nl to 3.49 nl. Embryo mortality is unusually frequent in those eggs of the backcrosses and of the parental strains that have volumes smaller than 1.5 nl. An egg volume of 1.5 nl represents in Ch. thummi the lower limit for those volumes that are sufficient for a normal embryogenesis. Mortality increases with decreasing egg size, reaching 100% in backcross eggs with volumes of 0.99 nl and smaller. Small egg size is a new trait of the Rud syndrome affected thummi female × piger male hybrids. This trait is part of a postzygotic reproductive isolation barrier between thummi and piger and manifests first in the backcrosses. Most backcross eggs show volumes between 1.5 nl and 2.99 nl. Within this volume range the amount of mortality does not depend upon egg volume. Here, embryo death is great in the backcrosses but normal in the parental strains. The high frequency of embryo death in the backcrosses must be predominantly due to the action of the Rud syndrome and a second hybrid syndrome, called HLE syndrome. Since further characteristic traits of these syndromes could be detected in surviving backcross individuals, the study demonstrates the occurrence of the syndromes in this generation also. Therefore, the postzygotic reproductive isolation mechanism of both hybrid syndromes is effective in the hybrids and in their progeny as well., Klaus Hägele, Monika Kasper-Sonnenberg, 4 obrázky, 2 tab., and Lit.
We measured energy substrates in haemolymph and flight muscles of the large blister beetle Mylabris oculata at rest and after tethered, lift-generating flight. Flight of 1 min duration at an ambient temperature of 38-42°C did not effect a change in the concentration of lipids in the haemolymph, whereas a small, significant decrease in the concentrations of carbohydrates and a 3-fold larger one in the levels of proline were noted, as well as a concomitant increase in alanine. In the flight muscles, glycogen and proline concentrations were diminished slightly but significantly upon flight, whereas alanine levels were increased. Two hours of rest after a flight of 1 min completely reversed the metabolic situation in haemolymph and flight muscles to pre-flight levels. We could isolate two neuropeptides from the corpora cardiaca of M. oculata, which by retention time and mass analyses are characterised as the decapeptide Del-CC (pGlu-Leu-Asn-Phe-Ser-Pro-Asn-Trp-Gly-Asn-NH2) and the octapeptide Tem-HrTH (pGlu-Leu-Asn-PheSer-Pro-Asn-Trp-NH2) previously fully identified from the corpora cardiaca of the blister beetle, Decapotoma lunata (Gäde, 1995). Subsequently, it was unequivocally demonstrated that low doses of Del-CC and Tem-HrTH elicited increases in the concentration of proline and carbohydrates in the haemolymph of D. lunata and M. oculata, but did not change the concentration of lipids in both species. In conclusion, the two endogenous peptides are hypertrehalosaemic and hyperprolinaemic, thus very likely regulating the mobilisation of the two important flight substrates of blister beetles, namely carbohydrates and proline., Gerd Gäde, Lutz Auerswald, and Lit
From 1994-1997 the food of Coccinella septempunctata L. was investigated on the basis of gut dissections of adults and larvae collected in the field. Additionally, the gut contents of adults fed under laboratory conditions were investigated. The likelihood of recovering different prey types during gut dissection was variable, which will be illustrated by presenting some common prey fragments. The food eaten by adult C. septempunctata throughout a year was studied at a locality in Berlin-Staaken. Ladybirds were collected from March 1994 until November 1997 in different crops and habitats on roughly a monthly basis. Aphid feeding was detectable from April until October. In May and June they were the most frequent food type. Fungal spores, in most cases the conidia of Alternaria spp., became most frequent in July. Additionally non-aphid arthropods were frequently preyed upon in July. A very common non-aphid prey item were thrips. Pollen was important in May and September. Comparing the food components of newly emerged adults with those of overwintered adults some remarkable differences were detected. In newly emerged adults non-aphid arthropods and fungal spores were much more frequent than in overwintered adults whereas aphids were less frequently found. The diet of adults and larvae was also investigated in June and July in cereal fields at two other localities, Northern Flaeming and Magdeburger Boerde. No difference in adult diet was found between the three localities. The composition of the larval diet was relatively similar to that of the adults., Holger Triltsch, and Lit
Four species of Anagrus (A. breviphragma Soyka, A. incarnatus Haliday, A. fennicus Soyka and A. obscurus Foerster sensu Soyka), that live on Carex riparia Curtis (Cyperaceae) in uncultivated areas along the Po river in the Piacenza province in Italy were analysed using RAPD markers in order to investigate their genetic relationships. High levels of RAPD polymorphism were found in the genus Anagrus, which permitted the fingerprinting of the four species. Analysis of average genetic similarities within species and comparison with average values between species confirms that A. breviphragma, A. incarnatus, A. fennicus and A. obscurus represent four genetically distinct species. A dendrogram constructed from molecular data of single families clearly clustered the four species in different groups, their mutual position reflecting morphological and biological observations., Elisabetta Chiappini, Lucia Soressi, Corrado Fogher, Marco Zanirato, and Lit