抄録
The dispersion-inducing repellent activity in the alimentary canal of the German cockroach was studied. Aqueous extracts of the oral secretion and of the foregut and midgut contents of the German cockroach had certain degrees of repellent activity to first instar nymphs of the same species when applied to preference tests. By gel filtration column chromatography, the repellent activity in the foregut extract was eluted into higher and lower molecular weight fractions (HMF and LMF), representing the same elution pattern observed in the oral secretion. These were supposed to be identical with the dispersion-inducing substances secreted in the saliva. In the midgut extract, only the LMF had repellent activity, and in the hindgut the activity in both the HMF and LMF was insignificant. On the other hand, aggregation activity was observed in the MeOH extract of the rectum and feces.Therefore, it is considered that the dispersion-inducing substances, or pheromones, are secreted in the saliva, and when swallowed thay are degraded in the alimentary canal. It is supposed that they do not interfere with the role of aggregation pheromone secreted from the rectal pads.
