Assertion: caterpillar's prolegs | /r/CapableOf | disappear by the time
Facets:
value: gradually
type: TEMPORAL
Source sentences:
text: However, several morphological differences can distinguish the two: while both larvae share three pairs of thoracic legs and an apical pair of abdominal prolegs, lepidopteran caterpillars have four pairs of prolegs on abdominal segments 3-6 while sawfly larvae have five pairs of prolegs located on abdominal segments 2-6; crochets are present on lepidopteran larvae, whereas on sawfly larvae they are not; the prolegs of both larvae gradually disappear by the time they burrow into the ground, therefore making it difficult to distinguish the two; and sawfly larvae only have a single pair of minute eyes, whereas lepidopteran larvae have four to six eyes on each side of the head.