1. Post Doctoral (UGC), New Delhi D.D.U. Gorakhpur University, Gorakhpur
Seasonal variation in toxicity of citral against sporocyst, redia and cercaria larva of Fasciola gigantia  
Dr. Kumari Sunita
Post Doctoral (UGC), New Delhi
Department of Zoology
D.D.U. Gorakhpur University, Gorakhpur
(UP) India

2. Fasciolosis is the vector- born parasitic disease showing the greatest latitudinal, longitudinal and altitudinal distribution know.
It is caused by two trematode parasite Fasciola hepatica and Fasciola gigantica found in Asia and Africa.
Fasciolosis has significant impact on growth, development and productivity in domestic ruminants.
The freshwater snail L. acuminata is an intermediate host of the F. gigantica in northern parts of the India.
According to WHO 2.4 million humans are infected with Fasciola and a further 180 million are at risk of infection.

3. Release of molluscicide in aquatic system for their control to kill the snails also affect the other non target organism.
One way to reduce the incidence of fasciolosis is to destroy the life cycle of Fasciola larval by in vivo and in vitro phytotherapy of host snail L. acuminata at sublethal dose of molluscicide.
It is a new approach to reduce the incidence of the fasciolosis without killing the snails
The use of plant product (Citral) Zingiber officinale are effective, less expensive and eco-friendly.

4. Life cycle of Fasciola gigantica
Primary host (Definitive host)
Sheep
Cattle
Other Mammals Humans
Humans (Accidental)
Intermediate host
Lymnaea acuminata
Geographic Range
Cosmopolitan; anywhere sheep and cattle are raised

5. Cercaria larva from Secondary Host Lymnaea acuminata
Immerging cercaria
Cercaria larva

6. Adult Fasciola gigantica from Buffalo Liver
Fasciola in Liver
Adult Fasciola gigantica

7. OBJECTIVEs
The objective of the present study is to explore the use of plant derived larvicidal component against different larval stages (sporocyst, redia, cercaria) found in the intermediate host snail Lymnaea acuminata.
1. Snails from different ponds in adjoining area were collected and acclimatized to laboratory condition. There after, they were dissected out under the microscope to observe the different larvicidal stage in snail body.
2. Infected snails were divided in two parts. One part were counted for larval infection without treatment (control) and second part was treated with different concentration (less than the ten times than LC50 value reported of snails) of Zingiber officinale and it active components respectively. Now these treated snails were dissected out after 2h, 4h, 6h, and 8h and number of dead and live larva were counted each month of the year.

8. 3. In vitro treatment of plant derived molluscicides were studied against different larval stage in water number of dead and live larva will be counted in each month of the year.
4. On the basis of mortality data against different larvae LC50, g value, heterogeneity factor, t- ratio and slope value were calculated by the POLO computer programme of Robertson et al (2007) (Bioassay with arthropods POLO computer programme for analysis of bioassay data 2nd Edition 1-224).
5. Effective concentration for killing different larval stage (sporocyst, redia, cercaria) were suggested without killing the snails.

9. Methodology
1.Toxicity study was done by the method of Singh and Agarwal (1984).(J.Nat. Prod.47, )
2. LC50, g value, Heterogeneity factor, slope, t-ratio was done by the method of Robertson et al (2007, pp1-224) Bioassay with arthropods POLO computer programme for analysis of bioassay data 2nd Edition 1-224
3. Product moment/ Rank correlation coefficient was done by the method of Sokal and Rohlf (1973) (Introduction to Biostatistics,freeman,W.H San Francisco).

10. Results
Figure.1. In vitro toxicity (LC50 mg/ml) of citral against sporocyst larva in different months of year
Figure.2. In vitro toxicity (LC50 mg/ml) of citral against redia larva in different months of year

11. Figure.3. In vitro toxicity (LC50 mg/ml) of citral against cercaria larva in different months of year
Figure.4. In vivo toxicity (LC50 mg/L) of citral against sporocyst and abiotic factors in different months of year

12. Figure.5. In vivo toxicity (LC50 mg/L) of citral against redia and abiotic factors in different months of year
Figure.6. In vivo toxicity (LC50 mg/L) of citral against cercaria and abiotic factors in different months of year

13. In vitro toxicity of citral In vivo toxicity of citral
Larvae
In vitro toxicity of citral
Mar
Apr
May
June
July
Aug
Sept
Oct
Nov
Dec
Jan
Feb
Sporocyst
Redia
Cercaria
Highest toxicity of Citral
Lowest toxicity of Citral
Larvae
In vivo toxicity of citral
Mar
Apr
May
June
July
Aug
Sept
Oct
Nov
Dec
Jan
Feb
Sporocyst
Redia
Cercaria

14. Findings
In vitro and in vivo larvicidal activity of citral against the sporocyst, redia and cercaria larvae of F. gigantica in different months of year is time and concentration dependent.
In vitro highest toxicity of citral against cercaria (8h LC mg/ml)/sporocyst (8h LC mg/ml) was observed in the month of July and August.
Lowest toxicity was noted in month of January (10.12 mg/ml)/November (15.49 mg/ml), respectively.
In in vivo 8h LC50 of citral against redia/cercaria and sporocyst larvae in month of August and July (8h LC mg/L, 3.27 mg/L) was (8h LC mg/L), respectively.
The lowest mortality was observed in between January-February.

15. Thank You