The ornamental design for an insecttrap, as shown and described.
1. Insect trap
1.1 : Perspective
1.2 : Front
1.3 : Back
1.4 : Left
1.5 : Right
1.6 : Top
1.7 : Bottom
1.8 : Reference
1.9 : Reference
1.10 : Reference
Reproduction 1.8 is a reference perspective view showing the state of closing the cover part, detaching the collecting bucket and folding the legs; reproduction 1.9 is a reference bottom view showing the state of detaching the collecting bucket and folding the legs; reproduction 1.10 is a reference bottom view showing the state of detaching the collecting bucket and unfoling the legs; reproductions 1.8, 1.9 and 1.10 are for reference purposes only and form no part of the claimed design.