THE connective-tissue sheath around the nervous system of insects began to attract attention after Hoyle (1953) had shown that it was essential for the normal functioning of the nervous system in Locusta migratoria. The sheath, which consists of two layers, the neural lamella and the sheath cells, controls the passage of ions from the haemolymph into the nervous system. In electron-microscope s...

A n existing test to m onitor the rate of adipokinetic horm one release from the corpora cardiaca (CC) of Locusta migratoria in vitro was improved, so that a constant basal ra te of release was achieved and the am ount of released Lom -AKH-I, II and III could be quantified by HPLC. This test system was subsequently used to dem onstrate that a small peptide, which has been found in a few insect ...

It is well-documented that endophytes can enhance the resistance of agronomical grasses, such as tall fescue and perennial ryegrass to herbivory. For native grasses, however, the related reports are limited, and the conclusions are variable. Achnatherum sibiricum is a grass native to the Inner Mongolian steppe. This grass is highly infected by endophytes but does not produce detectable endophyt...

The inhibitory innervation of the intersegmental (body wall) muscles between the first and the second thoracic segment of the migratory locust, Locusta migratoria, was investigated using neuroanatomical, immunocytochemical and electrophysiological techniques. Three neurons located in the prothoracic ganglion show GABA-like immunoreactivity and project into the intersegmental nerve. Two are comm...

The retent ion, tissue distr ibut ion, and localization of [22,23-H2 ]dihydroazadirachtin A was investigated in the female locust, Locusta migratoria. A constant quantity of 0.4 to 0.5 pg of dihydroazadiracht in A per gram body weight is recovered in the unchanged fo rm 5 days after in ject ion of any of the physiologically effective doses in the range of 1.5 to 3.0 pg/g. Malp ighian tubules ac...

Close to melting transitions it is possible to propagate solitary electromechanical pulses which reflect many of the experimental features of the nerve pulse including mechanical dislocations and reversible heat production. Here we show that one also obtains the possibility of periodic pulse generation when the constraint for the nerve is the conservation of the overall length of the nerve. Thi...

A full-length cDNA encoding a new cytochrome P450, CYP6L1, was cloned from German cockroaches, Blattella germanica. CYP6L1 has an open reading frame of 1509 nucleotides with a deduced protein of 503 amino acids and molecular mass of 57 Kd. CYP6L1 is most similar to CYP6H1, a putative ecdysone 20-hydroxylase from Locusta migratoria. CYP6L1 mRNA was not detected in embryos nor nymphs, nor in adul...

The biosynthesis of neutral fat-transporting lipoproteins involves the lipidation of their nonexchangeable apolipoprotein. In contrast to its mammalian homolog apolipoprotein B, however, insect apolipophorin-II/I (apoLp-II/I) is cleaved posttranslationally at a consensus substrate sequence for furin, resulting in the appearance of two apolipoproteins in insect lipoprotein. To characterize the c...