. ▁ ▁Since ▁P . ▁pen etr ans ▁is ▁a ▁mig rat ory ▁n emat ode , ▁they ▁can ▁move ▁from ▁plant ▁to ▁plant , ▁but ▁usually ▁do ▁not ▁migr ate ▁more ▁than ▁ 1 – 2 ▁meters ▁from ▁the ▁root ▁zone ▁that ▁they ▁first ▁inf ect , ▁thus ▁invasion ▁of ▁many ▁roots ▁can ▁take ▁place ▁in ▁the ▁n emat odes ▁life ▁span . ▁ ▁The ▁n emat ode ▁over w inter s ▁in ▁inf ected ▁plant ▁parts ▁or ▁in ▁the ▁soil ▁at ▁any ▁life ▁stage , ▁however ▁J 4 ▁is ▁the ▁optimal ▁life ▁stage . ▁ ▁Environment ▁ ▁The ▁n emat ode ▁is ▁found ▁in ▁all ▁temper ate ▁regions ▁around ▁the ▁world , ▁because ▁of ▁the ▁wide ▁host ▁range . ▁ ▁For ▁normal ▁n emat ode ▁activity ▁a ▁mo ist ure ▁film ▁is ▁needed ▁for ▁movement ▁of ▁the ▁n emat ode . ▁ ▁So il ▁mo ist ure , ▁relative ▁hum id ity , ▁and ▁related ▁environmental ▁factors ▁directly ▁affect ▁n emat ode ▁surv ival . ▁ ▁Mo ist ure ▁is ▁needed ▁to ▁the ▁n emat ode ▁to ▁surv ive ▁and ▁move . ▁ ▁When ▁the ▁n emat ode ▁is ▁inside ▁of ▁the ▁root , ▁the ▁root ▁provides ▁the ▁optimal ▁mo ist ure ▁and ▁protection ▁from ▁des ic cation . ▁P . ▁pen etr ans ▁has ▁a ▁critical ▁surv ival ▁mechanism ▁that ▁during ▁cold ▁seasons ▁and ▁in ▁the ▁absence ▁of ▁the ▁host ▁it ▁goes ▁into ▁dia p ause , ▁animal ▁d orm ancy ▁resulting ▁in ▁a ▁delay ▁in ▁development . ▁ ▁Root