CHINCH BUGS: Blissus leucopterus leucopterus, and B. insularis, Lygaeidae

ADULT: These small (1/8 to 3/16 in. long), slender bugs have black bodies and legs. The obvious white fore wings have a black triangular spot at the middle of the outer margins.  The species can be separated by examining the relative lengths of their mouthparts and distances between their compound eyes. However, the two species look very similar and should be identified by a trained taxonomist for accurate identification.

EGG: The translucent white eggs become reddish with age. They are inserted singly between leaf sheathes. Temperature greatly effects chinch bug development rates.  Nymphs emerge from eggs in 9 d at 83 degrees F, but take 25 d at 70 degrees F.

NYMPH: Newly emerged nymphs are pale yellow, but soon become red, except for the legs, antennae and the first two abdominal segments, which remain pale yellow. Second through fourth instars become progressively darker red. Fifth instar nymphs are black and gray with an obvious white spot on the back between wing pads.  There is no pupal stage in Lygaeidae. Nymphs complete development in 26 d at  83 degrees F and 69 d at 70 degrees F.

GENERATION TIME: 35 d at 83 degrees F, 94 d at 70 degrees F.

DAMAGE: Chinch bugs are occasional corn pests in Florida. B. leucopterus in the only species noted as a corn pest.  B. insularis (southern chinch bug) is found on the crop, but is not considered a corn pest. However, they can build to very large destructive populations in St. Augustine grass. While B. insularis is distributed throughout Florida, B. leucopterus has been recorded only from Holmes and St. John's counties in north Florida. Young plants are most susceptible and do not completely recover from chinch bug damage. Sucking mouthparts of chinch bugs damage leaves, particularly within the whorl, causing yellowing or reddening of affected tissue. The most serious damage is caused by stalk feeding at the base of the plant. This damage can result in stunting and yield loss. Severe damage includes lack of complete leaf emergence and dead leaves.

CONTROL: Planting as early as possible in areas with annual chinch bug problems will reduce damage. As few as 10 bugs per plant in young plants can have a yield affect. Twenty bugs on mid whorl stage plants can also reduce ear weight. Formulations, rates, and pre-harvest intervals of insecticides for chinch bug control are listed below for sweet corn (Table 1) and field corn (Table 2).