Our focused materials are Reclinervellus nielseni (wasp) which manipulates web building behaviour of host spider resulting in a cocoon web and its host spider Cyclosa argenteoalba which weaves a fine orb web for capturing prey but before moulting constructs a simple web that we call resting web without a sticky spiral and with conspicuous fluffy decorations on radii.

We found that the wasp larva induces the spider to modify its web form into a simpler and seemingly better designed web which is apparently similar to the resting web in the form and also in bearing fluffy decorations on the radii. To verify a hypothesis that the wasp evokes behaviour already programmed in the spider, we conducted behavioural observation and web-structure examination by means of SEM, a spectrometer and a tensile tester. As a result, we conclude that resting web is the origin of the cocoon web but additional modification of repeated thread weaving was recognized in manipulated behaviour. Specific decorations turned out to be functioning as an advertiser of the webs towards inadvertent flying web-destroyers.