 Like all arthropods , spiders moult and , after hatching , the life stage before each moult is called an " instar " . Specimens of P. fimbriata become mature at instar 7 , 8 or 9 . In an experiment using P. fimbriata spiderlings from Queensland , 64 % of those fed only on spiders survived to maturity , 37 % of those fed on a mixture of spiders and insects survived , and all those fed solely on insects died before reaching the 6th instar . For moulting , all Portia species spin a horizontal web whose diameter is about twice the spider 's body length and is suspended only 1 to 4 millimetres below a leaf . The spider lies head down , and often slides down 20 to 30 millimetres during moulting . : 496 Portia species spin a similar temporary web for resting . : 513 P. fimbriata in Queensland can be very sedentary , in some cases remaining in the same web for over 48 days during a series of moults . : 239 
