2004/08/01 by K. Maeno, Koutaro Ould Maeno, T. Gotoh +3 · 1 citation
Agricultural and Biological Sciences · Biochemistry, Genetics and Molecular Biology · Neuroscience · #Insect and Arachnid Ecology and Behavior #Neurobiology and Insect Physiology Research #Plant and animal studies
paper · doi:10.1079/ber2004310
crossref issued 2004/08/01 · crossref published 2004/08/01 · crossref published-print 2004/08/01 · openalex publication_date 2004/08/01 · crossref created 2004/08/07 · crossref published-online 2007/03/09 · openalex created_date 2016/06/24 · crossref deposited 2023/08/14 · crossref indexed 2026/07/30 · openalex updated_date 2026/07/31
The effects of a neurohormone, [His(7)]-corazonin, on phase-related morphological traits (F/C and E/F ratios; F = length of the hind femur, C = maximum width of the head; E = length of fore wing) were re-examined in the desert locust, Schistocerca gregaria Forskål. The F/C ratio was significantly different between adults with five and six nymphal instars, respectively, indicating that they need to be analysed separately. Injections of the synthesized peptide (1 nmol) into individually-reared (solitary) nymphs at the second and third instars caused a shift in classical morphometric ratio towards the value typical for crowded (gregarious) individuals in both sexes. The E/F ratio, which is smaller in solitary locusts than in gregarious ones, was also influenced significantly by injections of [His(7)]-corazonin into individually-reared locusts. The effect of [His(7)]-corazonin on E/F ratios was shown more clearly when the nymphs were injected at a higher dose (2 nmol) at the beginning of the third instar. Single injections of the peptide into individually-reared nymphs at different instars revealed that the earlier the injection the larger the 'gregarizing' effects of the peptide on F/C and E/F ratios. The same tendency was also detected in Locusta migratoria Linnaeus. These results supported the hypothesis that [His(7)]-corazonin plays an important role in the control of phase polymorphism in locusts.