In an effort to initially keep the pathogen out of the mosquito's internal compartments, the cuticle is the first line of defense to prevent infection (Hillyer, 2016) . As Hillyer stated, violation of this barrier can be through injury or through enzymatic digestion. Once internalized, pathogens are then subjected to a few main forms of degradation: cell-mediated phagocytosis, melanization and lysis (Hillyer, 2010). There are other forms of pathogen degradation and elimination, including RNA interference, but these methods are not as well understood (Hillyer, 2016). The cells of the mosquito immune system that regulate these processes are called hemocytes and can either circulate in the mosquito's hemolymph (circulating hemocytes) or be attached to a specific location (sessile hemocytes). The first method of elimination is phagocytosis, a very important response of the mosquito immune system that is executed by internalization by a hemocyte (granulocyte) of the pathogen particle into a phagosome followed by degradation via hydrolytic enzymes (Hillyer , 2010 and Hillyer, 2016). . Melanization is a process in which a series of phenoloxidase-based reactions occur that convert tyrosine into melanin precursors, forming a dark capsule surrounding the pathogen, resulting in its appearance.