Species composition and seasonal dynamics of mosquito larvae in the Wroclaw, Poland area.

A total of 13,214 larvae specimens representing eight species (Culex pipiens, Culiseta annulata, Ochlerotatus cantans, Ochlerotatus communis, Ochlerotatus excrucians, Ochlerotatus sticticus, Aedes vexans, and Anopheles maculipennis) from twelve sampling places in the Wroclaw area in Poland were collected between May and October, 1998-2000. The development rate of each mosquito species depended on hydrological types and various plant communities in water bodies. The water quality (temperature, pH and ion concentration) influenced mosquito larvae dynamics as well. The most abundant and constant species was Cx. pipiens. Its monthly population was significantly higher in the water bodies located in the city center as compared to those in the suburbs.

Entomopathogenic activities of environmental isolates of Bacillus thuringiensis against dipteran larvae.

Twenty-five field isolates of Bacillus thuringiensis from the Lower Silesia region of Poland, the Osola plain, and phylloplane niches and soil samples from the Karkonosze National Park were tested for insecticidal activity against larvae of the dipterans Aedes aegypti, Drosophila melanogaster and Musca domestica. The spore-crystal mixture of B. thuringiensis finitimus (soil isolate) killed nearly half of the fourth instar larvae of Ae. aegypti. Similar mortality of between 39-61% was recorded after treatment with two phylloplane isolates belonging to biochemical type I of B. thuringiensis (subsp. japonensis, yoso and jinghongiensis) and type IV (subsp. tochigiensis,). The effect of B. thuringiensis wratislaviensis H-47 was lowest, with larval mortality ranging from 7-28%. The susceptibility of D. melanogaster, evaluated as percentage of larvae that did not survive to adulthood, varied between 0-38% and 0-45% at dosages of 0.5 and 1 ml, respectively. The LC50s ranged from 5.07 x 10(9) to 1.04 x 10(11) spore-crystal mixture. The LC50s for M. domestica larvae were 4.1-4.8 x 10(8) spores/ml of B. thuringiensis finitimus and the phylloplane strain KpC1 (I type) and 2.9 x 10(9) for the phyloplane representative of group I. Generally, all tested isolates showed the most activity against common fly larvae. The highest (64-81% mortality) was observed after treatment with both phylloplane (OpPs1, KpF3, KpC1) and soil isolates (KsAc1) of biochemical type I as well as B. thuringiensis finitimus (type III).

[Toxicity of isolates of Bacillus thuringiensis from Wroclaw against larvae of Aedes aegypti]. / Toksycznosc wroclawskich izolatów Bacillus thuringiensis wobec larw Aedes aegypti.

Seven field isolates of Bacillus thuringiensis from the Lower Silesia, region of Poland, the Osola plain and phylloplane niches and soil samples from the Karkonosze National Park were tested in vitro for insecticidal activity against mosquito larvae Aedes aegypti. Both the spore/crystal mixture and pured crystals from B. thuringienis strains KpC1, KpF3 and OpQ3 (belonging to the first physiological group including the subspecies japonensis, yoso, jinghongiensis ) proved to be the most active against insects (61-65% of corrected mortality). The lowest toxicity (7-28% mortality) was caused by B. thuringiensis wratislaviensis strains (PO12 and 13).

[Introduction to biology and control of mosquitoes]. / Wprowadzenie do biologii warunkujacej srodowiskowe zwalczanie komarów.

Mosquitoes systematics, life cycle as well as morphology and bionomics of developmental stages, mosquitoes borne diseases, ecology and reemergence, vectorial capacity of some domestic species were presented with regard to mosquitoes control by the integrated methods and ecological prophylaxis.