With access to a clearer version of the leaked script, we see that Jing managed to identify the poisonous bug with his physician Hu Zhen's help. However, he did not appear to be given any further details in terms of the requirement to plant such a bug.
Leaked script Ep13 scene 2
Tushan Jing is in the study of Tushan manor in Zhi Yi city, looking extremely haggard, without a trace of a smile on his face, as he listened to Hu Zhen's report.
HZ: Clan leader, I have consulted people well-versed with poisonous bugs. What the princess has is likely the legendary male-female bugs from Bai Li. If a person is wounded, the other person will also be implicated.
TSJ (worried): Implicated to what extent? If a person dies, will the other person die too?
HZ (hesitant): No one has personally seen this happen. It is a possibility... that they will die.
Tushan Jing was stunned, his expression worried and distressed.
TSJ (VO): It is only a matter of time before Xuan Yuan laid siege on the Shen Nong remnant army. When the time comes, I fear Xiang Liu will... the poisonous bug in Xiao Yao's body must be removed as soon as possible.