Cyclodevelopmental life cycle is seen in:

Filaria Transmission of ahropod-borne diseases occur by following methods: 1.Direct contact - In this method of spread, the ahropods are directly transferred man to man e.g. scabies, pediculosis 2.Mechanical Transmission - Here the disease agent is transmitted mechanically by the ahropod. e.g. housefly transmitted diseases 3. Biological Transmission - In biological transmission the disease agent multiplies or undergoes some developmental change with or without multiplication in the ahropod host.It is of three types: a. Propagative - The agent merely multiplies in vector, but no change in form e.g. plague bacilli in rat flea. b. Cyclopropagative - The agent changes in form & multiplies in the body of ahropod e.g. malarial parasites in mosquito c. Cyclodevelopnzental - The disease agent undergoes cyclical changes but no multiplication e.g. filarial parasite in culex mosquito and guinea worm embryo in cyclops. Other methods Transovarian transmission - The infectious agent is transmitted veically from the infected female to her progeny in the vector e.g. Ticks transmitting Ricketssial diseases Trans-stadial transmission - Transmission of the disease agent from one stage of the life cycle to another as for example nymph to adult e.g. Ticks.