Arthropods

3. The chest portion on an arthropod.
5. The part on a spider that aids in weaving a web.
6. A large subphylum that includes insects.
7. A chemical substance produced and released into the environment that effects the behavior of other insects.
8. A type of excretory system in insects.
9. An aquatic arthropod such as a lobster or crayfish.
12. Appendages that are used for locomotion and reproduction.
13. A hard external shell made of chitin.
14. The shedding of the exoskeleton for growth.
15. An appendage near the mouth of the arthropod.
18. One of the internal respiratory tubes of insects and some other terrestrial arthropods.
19. The young of an insect that went through incomplete metamorphosis.
22. A growth cycle for insects with a pupa and larva stage.
25. An external respiratory opening on the side of an insect.
27. A specialized level in a colony of insects.

1. Invertebrae with jointed legs, a segmented body, and an exoskeleton.
2. The lower jaw.
4. A growth cycle for insects without a pupa stage.
10. A group of the Chelicerae.
11. Each of a pair of respiratory organs composed of many fine leaves.
16. The "tail" portion of an arthropod.
17. An appendage that has the large chelae.
20. The immature form of an insect (between larva and adult) in complete metamorphosis.
21. The section of an arthropod where the head and chest are combined.
23. A projecting part of an organism that has a specific purpose
24. The hard upper shell of a crustacean.
26. What the exoskeleton is made of.