Science Homework Help

Article: http://www.jstor.org/stable/10.1086/424681

Mosquitos are free-living vectors, interacting with the host only briefly during a bite, whereas ticks are sessile vectors, remaining on an individual host potentially for the majority of their lives.  Dobson stated that the abundance of vectors like mosquitos is likely to be independent of host abundance, whereas the abundance of vectors like ticks is likely to increase with host abundance. Why might this pattern arise?