ENT378 Lecture Notes - Lecture 5: Dung Beetle, Rhabditida, Rhabditidae
29 Dec 2018
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Document Summary
Evolution of parasitism from free-living forms: george o. poinar jr. Associations of nematodes and invertebrates. steps: (from free-living) phoresis - invertebrate serves as a means of transport only. see handouts. Order rhabditida - most primitive group gave rise to: ii. facultative parasitism - may parasitise insects but retain the iii. obligate parasitism - require a living host to complete life cycle. ability to develop and reproduce under free-living conditions. Scarab beetle; beetle rolls and feeds on dung; nematode lives in dung. Nematode will get onto the beetle. live in crap- beetle moves crap- lays eggs in the crap; Arisen in several orders: order diplogasteridav- phoretic, facultative, order tylenchida, order aphelenchida of. Both of these groups are largely plant feeders but many have become adapted to the parasitic lifestyle on invertebrates. They are characterised by the presence of a stomatostylet which may be used for the penetration. Lack stylets and most infect hosts as dauer or by ingestion of egg.
