I suspect you'll find that it isn't the insect that's the problem here, though I'm assuming that this part of your clients experience hasn't been addressed, forgive me if this is not correct. But from the description it is the contents of the insect rather than the insect itself. Many people have a 'yuk' phobia, some people do this with eggs for instance. To test for this you might try using a toy insect to see how she reacts, of course you'll have to tell her, and show her it's a toy, if she responds positively to this then that might indicate she is reacting to the contents, knowing there is no content to this toy might put her at ease, illustrating there is something more to her disgust. If it's the contents, as it would appear from your description, then I suspect you could say this is a normal feeling, though her reaction would then need to addressed.

If you can get to the specific issue it makes the CB process a lot easy. BTW, the term 'yuk' isn't exactly a scientific term however it conveys the idea in common terms.

You may also be interested to know it is my experience that clients presenting with this particular type of problem can also suffer, either at the time of presenting or at some later stage, Obsessive Compulsive Disorder. You might find the child is overly fastidious, or may even have ritualistic behaviours such as organising items in a certain way. She may say she does this because it keeps out the insects, it can be a precursor to the full blown version of OCD.