Starting with your organic forms with contour lines, these are generally looking pretty good. You're mostly sticking to the characteristics of simple sausages, although the ends do sometimes have a tendency to get a little pointy, so keep working on keeping them circular.

Continuing onto your insect constructions, overall your work here is honestly really well done, and to be completely honest, my complaints are pretty limited. So first, let's look at everything you're doing well:

Most importantly, you're paying a lot of attention to ensuring that every element you add to a construction is its own solid, complete, enclosed, three dimensional structures. A lot of students at this point have issues where they'll draw individual lines, or flat shapes, to help take shortcuts when building up their constructions, kind of jumping between 3D and 2D when it suits them. This however tends to remind the viewer (and the student) that they're really just looking at a flat drawing on a flat page, which in turn undermines the illusion they're trying to create. So, instead ensuring that all your forms are introduced as new, complete, solid structures is imperative, and establishing how they relate to the existing structure (either by defining the intersection between those forms with a contour line, or designing the silhouette of the new form to actually wrap around the existing structure as explained here). The only area where I feel you didn't do too great a job of this is the shell slapped on top of this insect, as that structure is much more complex and doesn't have the solidity of a simple 3D form, or one whose silhouette has been specifically designed to wrap around the existing body.

Aside from that, your linework is confident, you're definitely drawing with your whole arm, and while there are some areas where your drawings get a little messy (like this mantidfly) you're still focusing on these drawings as spatial reasoning exercises, not on going out of your way to ensure everything is clean and pretty. You're definitely getting a lot out of these exercises.

Now, there are a couple of areas where I feel you can improve.

Firstly, ease up on the contour lines. You've got a bit of a tendency to overuse them - specifically the ones that sit on the surface of a single form, like the mantidfly's abdomen, or this spider's abdomen and cephalothorax. This usually suggests to me that a student is piling them on "just 'cause", rather than actually putting the time in during the planning phase to ask themselves just what that mark is meant to contribute and accomplish. Contour lines like this suffer from diminishing returns, where the first one may have more impact, the second will have less, and the third may have virtually none.

Just to be clear, the intersectional contour lines that define the relationship between different forms are a whole different story. It's pretty much impossible to overuse them (since there's only one correct intersection to capture), and they are incredibly effective at making both relevant forms feel solid and 3D.

Secondly, I noticed that you seem to have employed a lot of different strategies for capturing the legs of your insects. It's not uncommon for students to be aware of the sausage method as introduced here, but to decide that the legs they're looking at don't actually seem to look like a chain of sausages, so they use some other strategy. There are of course plenty of others where you do strive to use proper sausage forms, but don't necessarily stick to all the sausage method's steps - for example, cases where you don't define the joint between the sausage forms with a contour line. The key to keep in mind here is that the sausage method is not about capturing the legs precisely as they are - it is about laying in a base structure or armature that captures both the solidity and the gestural flow of a limb in equal measure, where the majority of other techniques lean too far to one side, either looking solid and stiff or gestural but flat. Once in place, we can then build on top of this base structure with more additional forms as shown here, here, in this ant leg, and even here in the context of a dog's leg (because this technique is still to be used throughout the next lesson as well). Just make sure you start out with the sausages, precisely as the steps are laid out in that diagram - don't throw the technique out just because it doesn't immediately look like what you're trying to construct.

So! All in all, your work is coming along quite well. I'll go ahead and mark this lesson as complete.