[On the possibility of spontaneous interspecific hybridization in the nature of representatives of sibling-Species Chironomus riparius Kieffer and Chironomus piger Strenzke (Diptera, Chironomidae) from Armenia].

F2 hybrid (Chironomus riparius x Chironomus piger) x C. piger was found in mixed community of C. riparius and C. piger. Mechanism of its origin and problem of hybrid viability is considered.

[Blackflies (Diptera: Simuliidae) of North of Armenia].

The fauna of blackflies of North Armenia is represented by 12 species from the genus Simulium. The species composition in the Tavush Region is most diverse (10 species) versus that in the Shirak (n = 5) and Lori (n = 3) Provinces, which is due to a wide variety of Simuliidae breeding sites. Among the bioregulators of blackflies, there are microsporidia of 4 species, cabbageworms (Mermithidae), and caddisflies of the genus Hydropsyche. There is a preponderance of microsporidia among the blackfly bioregulators. The highest percentage (60%) of the larvae infected with microsporidia is noted in the second half of summer, which is related to their environmental conditions.

[Biological agents for controlling the density of blood-sucking black flies (Diptera: Simuliidae) in the north of Armenia].

Biological agents were found to have high larvicidal activity against Simuliidae of two Bacillus thuringiensis spp. israelensis strains. To reduce the number of the pre-imago stages of black flies, the biological agent BLP-2477 should be used as most effective from an environmental point of view.

[Neurohumoral regulation of gastric secretion in postvagotomy syndromes]. / Neirogumoralnaia reguliatsiia sekretornoi deiatelnosti zheludka pri postvagotomicheskikh sindromakh.

The secretion of hormones stimulating and inhibiting gastric secretory activity was studied in 85 patients with postvagotomy syndromes. The somatropin level was found to increase significantly in gastrostasis. The lower values of the blood insulin and C-peptide content in patients with recurrent ulcers was evidently associated either with insufficiency of the pancreatic insular apparatus or with partial vagal denervation, increased STH level, and plausible inhibiting effect of glucagon. Increased somatostatin secretion in the dumping syndrome, gastrostasis, and peptic ulcers may be due to the encountered hypergastrinemia.