Do dragonfly larvae live in water6/29/2023 In the present study, an attempt was made to assess the predatory potentials of dragonfly nymphs as biological control of water snails. have used dragonfly nymphs as biological control agent to overcome the schistosome bearing snails while Singh et al. Such qualities have together with the dragonflies and their larval stages as they are entomophagus in nature and frequently feed upon snails with longevity to spend their three- forth life span (1-3 years) in the aquatic habitat. However, the sustainable alternative needs to have distinct advantages and ability to kill the target species with easy applications, less expensive and non-pathogenic to biotic community. There are several biological control agents found in the fresh water resources like larvivorous fishes, water bugs, Coleopteran aquatic larvae, Crayfish, Cyclopes and Echinostome snails etc., those naturally helps in controlling the population of snails though they have their own barriers and capacity. Withstanding the facts of drug resistance, the biological control measures are reasonably appropriate as they are eco-friendly and beneficial for sustenance of aquatic flora and fauna. Inadequate uses of chemotherapeutics in practices with the reliance on chemical control have commenced harmful circumstances to the ecosystem with residual toxicity and resistance against the parasitic infections in animals. Thus it became major problem to the animal industry growth as worldwide 300 million bovines found annually exposed with the fluke parasites causing economic losses amounting more than 3.0 Billion US$. Frequent breeding of snails around the human community and their livestock occurs due to lift irrigation, pool of water and conventional water logging system in the rural areas. Fluke borne diseases are creating an alarming situation to sustenance of domestic and wild ruminants with the loss of agility due to apoptosis in the infected host cells that decrease the immunocompetency resulting untimely demises. Expansions of parasitic diseases are worldwide owing to the human rehabilitation and indiscriminate uses of natural resources. The fluke eggs usually passed in the faeces of domestic as well as wild herbivores and under suitable conditions of moisture and warmth larva called miracidia hatches and infect the water snails that act as intermediate host. Similarly the water snails ( Indoplanorbis exustus and Lymnaea luteola) are also habitat to the stagnant water resources. Introduction The dragonflies ( Palaeophlebia) are useful predacious insect and their nymphs grow in the fresh water resources like rainy season ditches, river pools, ponds and marshy lands etc. The predacious nature and potentials of the dragonfly nymphs may be promoted as one of the appropriate biological control agent to overcome the snail borne parasitic diseases.ġ. Remarkable reduction (82-97 %) in the cocoons and young snail population were noticed whereas 18-40% mortality have also encountered in the snails of control group. The pond water quality analysis was envisaged, average dissolve oxygen (DO- 0.4-0.7 ppm), hydrogen ion concentration (pH-6.7-8.7) and total dissolve solids (TDS-71-84 ppm) during the entire period of experiment. Observation recorded from 0, 3, 6, 12, 24, 48, 72 and 96 hrs of nymphs entry while feeding activity of nymphs was judged by counting the remaining numbers of snails and their larval stages in the different containers. The collected water bodies were used in the requisite quantity in glass containers of 6 litre water capacity each with snails, aquatic weeds and dragonfly nymphs for trial groups while the container of control group was kept without dragonfly nymphs. The water snails (snail’s cocoons, young snails and adult snails etc.) and dragonfly nymphs were collected from stagnant water resources of protected areas and brought to laboratory, maintained with aquatic weeds and mulberry leaves in the artificial cement tank. The predatory potential of dragonfly nymphs was studied on water snails ( Indoplanorbis exustus and Lymnaea luteola) and their larval stages under laboratory conditions.
0 Comments
Leave a Reply. |