title: A comparison of phase-related shifts in behavior and morphometrics of an albino strain, deficient in [His(7)]-corazonin, and a normally colored Locusta migratoria strain.
abstract: The albino Okinawa strain of Locusta migratoria is deficient in the neurohormone [His(7)]-corazonin. This peptide induces darkening of the cuticle, one of the typical features of gregarious locusts. As part of a broader study on the possible role of [His(7)]-corazonin in phase transition, we explored whether corazonin-deficiency might be associated with differences in behavior and morphometrics between albino and normal phenotypes of L. migratoria. Using a modification of the logistic-regression assay of behavioral phase state previously derived for Schistocerca gregaria, we found that there were strain dependent behavioral differences between crowd-reared nymphs of the albino Okinawa and the normally colored African strain, with no evidence of the albino strain being obligatorily solitarious. However, upon isolation, a shift towards more solitarious behavior occurs in both strains, even more profoundly in the Okinawa albinos. A shift could also be recorded in morphometrics. The conclusion is that the albino strain, although showing some solitarious features even when crowd-reared, is not, as has been suggested, obligatory solitarious and, as a consequence, the complete absence of corazonin is not sufficient to bring about the solitarious state.
authors.affiliation: Zoological Institute, K.U. Leuven, Naamsestraat 59, B-3000, Leuven, Belgium
authors.forename: B
authors.initials: B
authors.lastname: Hoste
authors.forename: S J.
authors.initials: SJ
authors.lastname: Simpson
authors.forename: S
authors.initials: S
authors.lastname: Tanaka
authors.forename: A
authors.initials: A
authors.lastname: De Loof
authors.forename: M
authors.initials: M
authors.lastname: Breuer