00423nas a2200109   4500008004100000245011500041210006900156300001100225490000700236100002100243856004900264       1978                        eng d00aThe male reproductive system of the dragonfly, Diplacodes trivialis Rambur (Odonata, Anisoptera: Libellulidae)0 amale reproductive system of the dragonfly Diplacodes trivialis R  a232-420 v271 aSrivastava, B, K  uhttps://worldodonata.myspecies.info/node/28401594nas a2200121   4500008004100000245008800041210006900129300001000198490000700208520119200215100001601407856004901423       1978                        eng d00a[Demonstration of life cycle with four obligatory hosts of the Hemiurid Trematodes]0 aDemonstration of life cycle with four obligatory hosts of the He  a75-920 v533 aResearch on the transmission of Hemiurid Trematode Halipegus ovocaudatus in experimental and natural conditions demonstrates the following: –the miracidium grows into a sporocyst producing rediae in the Mollusc Planorbis planorbis; – the cystophorous cercariae become mesocercariae in the hemocoele of Copepodes or finally Ostracodes when swallowed; – the mesocercariae become matacercariae in the mesenteron of larval Odonates (Zygoptera and Anisoptera) when these larvae swallow the Crustacea; – the metacercariae become become adults in the Amphibial Rana ridibundal perezi which feeds on dragonflies. The four hosts (Mollusc – Crustacean – Odonat – Amphibian) are obligatory in the life cycle for it is impossible to infect the Insects directly with the cecariae or the frog (tadpoles as well as adults) with the mesocercariae. The different stages of the life cycle of H. oveocaudatus aredescribed and the mode of the transmission is compared with the other species of Halipegus and with the Trematodes in general. The adaptative value of the lengthening of the cycle is discussed from the point of view of the conquest of terrestrial hosts by the Hemiurid Trematodes.1 aKechemir, N  uhttps://worldodonata.myspecies.info/node/285