Molecular content of the female’s accessory glands and oocytes were studied in crowded (gregarious phase) and isolated (solitary phase) Schistocerca gregaria adults using electrophoretic, chromatographic and immunological techniques. Quantitative differences were found in the presence of a proteic band between 28 and 38 KDa and a peptide with a retention time of 37.20 min in the accessory glands. Their presence in much higher concentrations in the crowd-reared (gregarious) phase than in the isolated-reared (solitarious) one suggests a role in phase polyphenism. This result was confirmed by western blot assay; an antiserum of crowdreared female’s accessory glands was raised against the gregarious and solitarious extract of female’s accessory glands shows a supplementary proteic band between 28 and 38 KDa in gregarious phase. An additional western blot analysis was successfully done in gregarious and solitary oocytes shows the same supplementary band between 28 and 38 KDa in gregarious oocytes, absent in the solitary ones. This concordance in our results shows that there was a gregarizing factor transmitted from the gregarious S. gregaria mothers to their progeny.
