Ram Pratap Yadav — новинки

The snails belonging to the family Lymnaeidae are known to act as intermediate host of both animal and human fascioliasis causes trematodes. Although the snails do not play an active role in transmission of the parasite from one host to another, as insect vectors do it is an indispensable intermediate host for the development of the parasite. The transmission of the infective stage of the parasite is accentuated through shedding of the cercariae by the snail host and the various human water contact activities. Two freshwater harmful snails Lymnaea acuminata and Indoplanorbis exustus is the intermediate host of the Fasciola hepatica and Fasciola gigantica, which causes endemic fascioliasis in cattle’s and livestock in northern part of India. A large variety of domestic animals such as, Cow, buffalo, sheep, goat, horses, donkeys, deer, rats, camels and rabbits, show infection rates that may reach 90% in some areas and consequently leading to significant economical losses annually. In a survey it has reported that 94% of the buffaloes slaughtered in Gorakhpur district (U.P.) had moderate to heavy infection of Fasciola hepatica.

There are a very large number of plants which contain compounds lethal to terrestrial as well as aquatic pests at doses which are some times below those for synthetic pesticides. Use of such products has the additional advantage that these likely to cause contamination of the environment. After all, such compounds are not confined to the plants in which they are found but also possibly get distributed in the environment through air and water. Most of the studies have been done in this area however suffer from one common drawback. While there is much information on the toxicity and lethal doses of plant pesticides, very little literature is available on their mode of action and affect on non-target organisms. For a large number of plants, data from field studies is lacking. Obviously these, substance cannot be put to commercial use without a study of these aspects as well. The freshwater snail Lymnaea acuminata and Indoplanorbis exustus are commonly found in Northern part of India. These snails are intermediate host of liver flukes Fasciola hepatica and Fasciola gigantica, which causes endemic fascioliasis in cattle and live stock population in this region.