Ecdysome 20-hydroxylase from the midgut of the tobacco hornworm (Manduca sexta L.).

An ecdysone 20-hydroxylase enzyme system that converts alpha-ecdysone to 20-hydroxyecdysone was prepared from the midgut of the tobacco hornworm prepupa. This partially purified enzyme is NADPH dependent and is localized in the mitochondrial fraction of the midgut tissue.     

Ecdysone 20-hydroxylase from the midgut of the tobacco hornworm (Manduca sexta L.)

Summary An ecdysone 20-hydroxylase enzyme system that converts -ecdysone to 20-hydroxyecdysone was prepared from the midgut of the tobacco hornworm prepupa. This partially purified enzyme is NADPH dependent and is localized in the mitochondrial fraction of the midgut tissue.     

Nitroġenous excretory products of tobacco hornworm,Manduca sexta (L.)

Zusammenfassung Die stickstoffhaltigen Exkretionsprodukte von Raupen vonManduca sexta L. wurden papierchromatographisch analysiert. Die wichtigsten ausscheidungsprodukte sind Harns?ure und Allantoin: Harnstoff wird nur in Spuren ausgeschieden.      

Degradation of pheromone biosynthesis-activating neuropeptide (PBAN) by hemolymph enzymes of the tobacco hornworm,Manduca sexta,and the corn earworm,Helicoverpa zea

The tritium-labeled bis-norleucine analog ofHelicoverpa zea pheromone biosynthesis-activating neuropeptide ([³H]NLPBAN) was incubated in vitro with hemolymph fromManduca sexta orH. zea adult females. The incubations resulted in the formation of several tritium-labeled degradation products. At a [³H]NLPBAN concentration of 0.9 μM the degradation proceeded at a very slow but physiologically plausible rate (2–10 fmol/min/μl hemolymph). The primary [³H]NLPBAN degradation reaction inM. sexta hemolymph was not inhibited by 20 μM leupeptin, 0.1 mM amastatin, 1 mM EDTA, 1 mM EGTA, 1 mM 1,10-phenanthroline, or 2 mM 4-(2-aminoethyl)benzenesulfonyl fluoride; but secondary reactions may have been affected, as some of the inhibitors changed the radio-HPLC profile of the degradation products. It is concluded that hemolymph ofM. sexta andH. zea contains peptidase(s) capable of inactivating circulating PBAN.     

Ultrastructure of photoreceptor cells in a vitamin A-deficient moth (Manduca sexta)

Zusammenfassung Die LepidoptereManduca sexta wurde während mehr als 20 Generationen ohne Vitamin A aufgezogen. Feinstrukturelle Veränderungen traten auf: Die Photorezeptorzellen zeigten starke Zunahme und Desorientierung der Mikrovilli des Rhabdoms. Mitochondrien waren aus der Normallage nahe am Ursprung der Mikrovilli gegen die Peripherie der Retinulazelle verschoben. «Zwiebelkörper» (Sammlungen von konzentrisch angeordneten Mikrovillimembranen) und eine grosse Anzahl von Mikrotubuli wurden in den interretinulären Zellen gefunden. Mit Pflanzendiät aufgezogene Insekten hingegen zeigten keine der beschriebenen Ultrastrukturänderungen.     

The phospholipids of the tobacco hornworm,Protoparce sexta Johan. (Lepidoptera; Sphingidae)

Zusammenfassung Es wird gezeigt, dass es sich bei den Phospholipiden vonProtoparce sexta vorwiegend um Phosphatidyläthanolamin und Phosphatidylcholin handelt, dass aber ein wichtiger kleiner Bestandteil eine Verbindung enthält, die zunächst als Alanin identifiziert wurde.

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Supported in part by a grant from the US Public Health Service, A10-04464.

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Contribution from the Entomology Department, North Carolina Agricultural Experimental Station, Raleigh. Published with approval of the Director of Research, Paper No. 1795 of the Journal Series.     

Growth,development, feeding preference,and food consumption and utilization by tobacco hornworm on tobacco mosaic virus-infected and non-infected tobacco leaves

Summary Plant disease may cause a variety of changes in plants which influence their suitability to insect herbivores. The reported physiological changes in tobacco due to infection by tobacco mosaic virus have the potential to influence the feeding, growth and behavior of the tobacco hornworm,Manduca sexta. However, feeding on foliage of systematically infected plants had no statistically significant effects on development time, mean pupal weight or the amount of foliage consumed by 4th instars. Although an initial preference was exhibited by larvae for healthy leaves after about 72 h no differences were observed. These results do not support the results of previous research on the influence of tobacco mosaic virus-infected plants on the tobacco hornworm.Scientific contribution No. 8130, article No. A-5071, of the Maryland Agricultural Experiment Station, Department of Entomology     

Effect of reserpine on the larval-pupal moult of the wax moth Galleria mellonella L. (Lepidoptera)

Significant retardation of G. mellonella development was induced by reserpine injected to the last instar larvae in doses having a long-lasting effect on the neurosecretory system.     

Desmosterol as a common intermediate in the conversion of a number of C28 and C29 plant sterols to cholesterol by the tobacco hornworm

Résumé Manduca sexta (Johannson) est capable de transformer 7 phytostérols en cholestérol. Ainsi, cet insecte peut déalcoyler le - et le-méthyl de même que les groupes méthylène et éthylidènes du carbone 24 et peut hydrogéner la double liaison 22, 23. Quand ces stérols sont combinés au 20, 25-diazacholestérol, on a constaté dans tous les cas que la transformation en cholestérol s'effectue par l'intermédiaire commun, le desmostérol.     

Identification of an oviposition-regulating pheromone in the European grapevine moth,Lobesia botrana (Lepidoptera: Tortricidae)

The oviposition of the European grapevine moth (EGVM)Lobesia botrana can be deterred by an extract of conspecific eggs corresponding to 20 egg equivalents. The reduction of the oviposition behavior is dose-dependent. Nine chemicals have been extracted from the eggs and identified as straight chain fatty acids and esters of fatty acids. A mixture of these rather simple molecules induces the same levels of deterrence as the total extract. It might be possible to use oviposition regulating pheromone in the future for the control of EGVM populations.     

Sex pheromones of the armyworm moth,Spodoptera exempta (Wlk.

Zusammenfassung Es wurden mit gas-chromatographischer Elektroantennogramm-Methode (Z)-9-tetradecenyl-1-acetat und (Z)-9, (E)-12-tetradecadienyl-1-acetat als die Sexuallockstoffe weiblicherSpodoptera exempta (Wlk.) identifiziert.

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Acknowledgment: We are grateful to Mr.C. Rivers, Unit of Insect Virology, University of Oxford Field Station, for supplying insect pupae.     

Juvenile hormone in larval diapause of the codling moth,Laspeyresia pomonella L. (Lepidopterae,Tortricidae)

Summary Whereas in last instar larvae ofL. pomonella kept under long-day-conditions (LD), the JH-titer is temporarily reduced to zero, it stays relatively high in short-day-conditioned (SD) larvae which enter diapause. Application of JH or a juvenoid to LD-larvae results in diapause, if the treated insects are kept under SD-conditions. From these results it is concluded that inL. pomonella diapause is initiated by a relatively high titer of JH during the last larval instar.