The "Main Trio Arc" is the first season of Insects and Arachnids, and has a total of 25 episodes.
| Name | Overview | Episode Number | Episode Number Overall |
|---|---|---|---|
| Party Crasher | Pierre Swallowtail enjoys the finer things in life; Good food, expensive clothing. But after calling the cops when a member of an infamous gang crashes his party, he finds himself inadvertently tied into the life of a crime fighter. | 1 | 1 |
| Undercover Swallowtail | Underestimating the job, Pierre sets off on his first case. Catching a gang carrying out a crime can't be that difficult, right? | 2 | 2 |
| Three Is A Crowd | Pierre's third case has seemingly gone much better than the first. However, everything changes when Pierre meets an arrogant mosquito, much different from his expectations. | 3 | 3 |
| Secrets | Frequently losing his notes and seeing the same two faces around is making Pierre suspicious. However, due to a recent run in with a certain gang, he will have to make a choice between focusing on the case or finding out the true secrets about these familiar faces. | 4 | 4 |
| Shieldbug's Fury | With the decision made, Pierre begins to conduct his own research, though not without catching some special attention. | 5 | 5 |
| Certainty | After reviewing the latest footage, Will becomes wary of Pierre's latest goal. The butterfly begins to believe that the mysterious duo could be an asset to finding out new information, but how he will recruit them is his latest conquest. | 6 | 6 |
| Plans | Finally getting the courage, Pierre puts his plans into action. Part 1: Talking to this 'suspicious' mosquito. | 7 | 7 |
| Further Encounters | Still troubled after his encounter with Skeeto, Pierre accidentally gets involved between a fight with The Black Beetles. With the entire case ending up in jeopardy, Will offers Pierre a deal. However, just after Pierre leaves carefully to discover more secrets, Will and some fellow police are cornered by the same gang. | 8 | 8 |
| Case After Case | Seeing the party crasher so close in person leaves Pierre in a confused position, rethinking about whether he would want either him or Skeeto on the team at all. However, he has other cases to solve, cases that may prove he's not a failure. | 9 | 9 |
| Two Is Better Than One | After his encounter with the Black Beetles, Will decides to put his career in jeopardy by getting much more involved in Pierre's cases. It proves to be more difficult than what he originally had thought, as both of their uncertainties clash. Will they ever be able to finish what was meant to be simple? | 10 | 10 |
| Tangled | Accidentally stumbling into another gang's hideaway, André has seemingly gone missing. Pierre, still on a mission to recruit the beetle, along with Will, has no other choice but to make up a lie to Skeeto in hopes that the mosquito will help find André. Now, with both André and Skeeto trapped, and his partner no where to be found, Pierre has no other choice but to save all three of them. | 11 | 11 |
| 12 | 12 | ||
| 13 | 13 | ||
| 14 | 14 | ||
| 15 | 15 | ||
| 16 | 16 | ||
| 17 | 17 | ||
| 18 | 18 | ||
| 19 | 19 | ||
| 20 | 20 | ||
| Breaktime | The trio discover that some things aren't as 'easy as ABC' when their latest case send them back to school. Finding out that the high school cliques still apply to them, can they remain focused? | 21 | 21 |
| Cliques | With the dance rapidly approaching, it soon becomes time to find the perfect partner. However, doing so begins to cause spurs of jealousy. Will this risk exposure of the case or will everything be able to be kept undercover? | 22 | 22 |
| The Dance | The time of the dance has finally arrived, but whilst everyone is enjoying the highlight of the school year, three different suspects have been picked. Which one could it be? | 23 | 23 |
| All Over | Due to a threat from the boss, André has no choice but to reveal all he knows, unwittingly putting Pierre and Skeeto into harms way. | 24 | 24 |
| Five Turns To Four | Learning of his ex boss' plan, André warns Pierre. But doing such things leads to consequences and someone finds themselves paying the price. | 25 | 25 |