The southern chinch bug, Blissus insularis (Barber), is the most
damaging insect pest of St. Augustinegrass. It will occasionally feed
on other grasses including bermudagrass, bahiagrass, zoysiagrass, and
centipedegrass. The distribution of B. insularis ranges from southern
North Carolina south to the Florida Keys and westward to central Texas.
Damaging populations have also been reported in southern California,
Mexico, and Hawaii.
The hairy chinch bug, Blissus leucopterus hirtus (Montandon), is a
serious pest of cool season turfgrasses. Preferred hosts are fine
fescues, perennial ryegrasses, bluegrasses, bentgrass and zoysiagrass.
These grasses are also susceptible to damage by the common chinch bug,
Blissus leucopterus leucopterus. The physical appearance of these
species is very similar and it is difficult to positively identify
which species is infesting cool season turf. The hairy chinch bug is
distributed through eastern Canada and the northeastern United States
as far south as Virginia and west to Minnesota.
The Buffalograss chinch bug, Blissus sp, is a common pest on Buffalograss and resembles the hairy chinch bug.
Adult chinch bugs are black with white wings and are 3.0-3.6 mm
long. Some adults possess short, non-functional wings. Chinch bugs
develop through five nymphal instars. First and second instars of the
southern chinch bug are bright orange while the third and fourth
instars are dark red and the final instar is black and closely
resembles the adult. First and second instars of the hairy chinch bug
are bright red; the third instars are orange; the fourth instars are
orangish brown; and the final instar is black. The eggs of all species
are white and oval with a blunt end and measure 0.25 X 0.75 mm.
Chinch bug development is temperature dependent, and eggs may
require as little as one week to hatch during the summer but may
require more than a month during the spring. Nymphal development
typically requires four to six weeks during the summer. Southern chinch
bugs produce three to seven generations per year, depending on the
geographic location and weather. Hairy chinch bugs produce two
generations per year from southern New England through the Middle
Atlantic states and west to Ohio. One generation of hairy chinch bugs
is produced per year in upstate New York and southern Ontario, Canada.
Chinch bugs damage turf by inserting their piercing-sucking
mouthparts into the crowns, stems and stolons of grass plants to remove
sap. During this process they inject a toxin that causes the grass to
turn yellow. Thus, damage appears as irregular yellow patches of turf.
These areas turn reddish brown and eventually die, while the chinch
bugs move outward into healthy turf. A yellow halo around the damaged
area is typical of a chinch bug infestation. Damage from chinch bugs
shows up first in sunny areas with heat or drought stressed grass and
which is often areas near pavement or sidewalks. Although damaging
infestations commonly occur from June into September, weather
conditions may prolong this period, especially in the range of the
southern chinch bug. In south Florida, all stages of the southern
chinch bug are present during the entire year.