Sekretion von Mucopolysacchariden im weiblichen Geschlechtsapparat von Pimpla turionellae L. (Hym., Ichneumonidae)

Summary

Histochemical tests on mucopolysaccharides were performed, the structures tested were the accessory glands and oviducts of the female genital system of the ichneumonid parasite, Pimpla turionellae L. Using the Alcianblue and Toluidinblue staining technique the production of mucopolysaccharides was observed in the bases of the oviducts as well as in the voluminous uterus glands (Fig. 2A), but not in other glands. The uterus glands are a pair of vesicles situated on the uterus and connect with the latter directly behind the openings of the oviducts (Fig. 1). Their function has been dubious until now.

Fig. 2B gives evidence that the chorion of the egg is contaminated with mucopolysaccharide within the oviduct. When passing through the uterus the eggs seem to be coated with an additional mucopolysaccharide film derived from the uterus glands.

Referring to Salt's (1970) opinion about the role of mucopolysaccharides in insect immunity, the mucopolysaccharide film is considered to protect the parasite egg from the hemocytic defence reaction of the host and possibly the chemical is responsible for the so called surface effect of the eggs of various parasite species. Experimental evidence, however, is still needed.

Zusammenfassung

In der paarigen Uterusdrüse und im Basalteil der Ovidukte der Weibchen von Pimpla turionellae L. — einem endophagen Puppenparasiten — wurde die Sekretion von Mucopolysacchariden nachgewiesen. Schon in den Ovidukten werden die Eier mit einem oberflächlichen Sekretfilm versehen, der bei der Passage der Eier durch den Uterus durch die Sekrete der Uterusdrüsen noch verstärkt werden dürfte. Es wird vermutet, daß der oberflächliche Mucopolysaccharidbelag die Eier vor der hämocytären Einkapselung durch den Wirt schützt und damit die chemische Natur der „Oberflächenwirkung“ tolerierter Parasiteneier darstellen könnte.