Starting with your organic forms with contour curves, you're largely doing a good job here. You're very close to maintaining the characteristics of simple sausages here, although some of them end up with ends that are a little more stretched out (rather than remaining entirely circular), nad some of them get a little wider through their midsections. Nothing too significant, just things to keep an eye on. The contour lines themselves are looking good, and I'm glad to see that you're aware of how their degree shifts wider as we slide away from the viewer.

Continuing onto your insect constructions, you're honestly doing really well, and my primary complaint is that you haven't left me with much to complain about. It's very clear that throughout these constructions you're building things up steadily, one step at a time, introducing new simple forms to build upon the existing structure and gradually work your way to a more complex overall result. You're also making good use of the sausage method in most of these cases, establishing a strong base structure/armature for your leg constructions, then building on top of them with additional forms to add bulk where it's necessary.

One thing that did catch my eye was your use of line weight. In cases like this weevil, I noticed that your line weight seemed to be a little more arbitrary - with some sections of forms' silhouettes being made notably darker/heavier, but not for any specific reason. One thing to keep in mind with line weight is that it's best to focus the tool on solving specific problems, consistently throughout your drawings. The best thing to do with line weight here is to allow it to clarify how specific forms overlap one another, in specific, localized areas. As shown in this example of two overlapping leaves, by focusing the line weight where those overlaps actually occur, we can help show the viewer which form is in front of which.

One way to think about it is that two lines that cross each other, maintaining the same weight, are like a 4-way intersection. The viewer's eye could ostensibly reach the intersection, then choose to follow any one of the 3 equally valid options. Go straight, turn left, turn right. Applying line weight helps take that intersection and turn it into an overpass, with one line going over top of the other, and eliminating the viewer's choice. Using line weight in this way, instead of applying it more arbitrarily, can help a great deal.

Furthermore, you'll definitely want to avoid having line weight jump from the silhouette of one form to another, as you did here on the weevil's leg. Jumping from the basic sausage to the section that was added to it after the fact causes all of these forms to kind of smoothly blend into one another. That initially sounds like what you'd want, but in fact it removes a lot of the complexity and nuance of our structure, and flattens it out into more of a graphic shape. Treating every new form as being separate components that come together to create something complex together, is best. They don't stop being individual entities, but they work together.

Looking at the approach you're using to build upon your insects' sausage structures, I think you're mostly going in the right direction here, but one thing that helps is to maximize just how much of that new added form's silhouette actually makes contact with the existing structure. As shown here, I like breaking the additional masses into separate pieces that twist around the existing structure, because it exposes more of the form's edge to the underlying sausage it's meant to wrap around. You can see this applied further in this ant leg demo.

The last thing I wanted to share is that when you add spikes/little protrusions to your insect constructions (as you did with the praying mantis' arms), make sure that you're thinking about how the spike itself wraps around the arm. That end that makes contact can be curved inward to establish that spatial relationship. You'll see an example of this in the bottom right corner of this lobster demo, though I also demonstrate the concept here.

So! As a whole, you're doing very, very well. There are some areas where you can certainly improve, but as it stands you're very much moving in the right direction. I'll go ahead and mark this lesson as complete, so keep up the great work.