GRAY LAWN LEAFHOPPER: Exitianus exitiosus, Cicadellidae

ADULT: Body and wing color are more or less gray with no distinguishing marks.  Crown of head is smooth.  Rear tibia are held forward under femora in preparation for jumping. Females live an average of 32 d at 70 degrees F and have a 4 d pre-oviposition period. These leafhoppers are often found in aggregations. 

EGG: Eggs are deposited just under the leaf epidermis in clusters of three to six. Nymphs emerge in 12 to 13.5 d at 70 degrees F.

NYMPH: Nymphs pass through five instars in 43 to 47 d at 70 degrees F. Egg clusters result in clusters of nymphs.  There is no pupal stage in cicadellids.

GENERATION TIME: 55 to 60 d at 70 degrees F.

DAMAGE: Gray lawn leafhoppers do well on lots of grasses, but prefer Bermuda grass. They transmit the diseases corn stunt spiroplasma (CSS) and maize bushy stunt phytoplasma (MBSP). These diseases are more common in south Florida, where local outbreaks causing economic losses have occurred.

CONTROL:  Leafhoppers rarely reach densities in Florida corn that require insecticides to prevent feeding damage.  Parasitic wasps attack leafhopper eggs, and spiders are important predators of nymphs and adults. The biggest concern for damage is associated with virus transmission.  Research has shown that pesticides are an inefficient means to prevent primary virus transmission, but some success is known for persistent viruses. Virus diseases are probably held largely in check by lack of virus reservoirs. Varietal resistance in corn to insect-transmitted virus is being addressed by several plant breeders and has the greatest potential for disease prevention. Several insecticides currently used to control fall armyworm also kill leafhoppers. Pesticides are available for foliar applications. Formulations, rates, and pre-harvest intervals of insecticides for gray lawn leafhopper control are listed below for sweet corn (Table 1) and field corn (Table 2).

Table 1.  Chemical control of leafhoppers in sweet corn
Insecticide, formulation Rate/acre Min. days to harvest Application notes
carbaryl (Sevin, Sevin XLR Plus) 4 F, 4 EC 1 - 2 qt 2 ears; 48 forage; 14**  
carbaryl (Sevin) 80 WSP 1.25 - 2.5 lb 2 ears; 48 fodder; 14**  
oxydemetonmethyl (MetaSystox-R) 2 EC 1.5 - 2 pt 7 - 1 app.; 21 - 2 app.  
permethrin (Pounce) 25 WP 6.4 - 12.8 oz 1  
permethrin (Pounce) 3.2 EC 4 - 8 fl oz 1  
permethrin (Pounce WSB) 24.7% WSB 6.4 - 12.8 oz 1  
pyrethrins + piperonyl butoxide (Pyrenone) 66% L (EC) 2 - 12 fl oz 0  
pyrethrins + rotenone (Pyrellin) EC 1 - 2 pt 12 hr  
soap, insecticidal (M-Pede) 49% EC 2 gal/100 gal water 0  
**harvest or grazing of forage or silage


Table 2.  Chemical control of leafhoppers in field corn
Insecticide, formulation Rate/acre Min. days to harvest Application notes
carbaryl (Sevin, Sevin XLR Plus) 4 F, 4 EC 1 - 2 qt 48 fodder, grain; 14**  
carbaryl (Sevin) 80 WSP 1.25 - 2.5 lb 48 fodder, grain; 14**  
disulfoton (Di-Syston 8) 8 EC 1.2 fl oz / 1000 row-ft 28 banded at plant or injected post-plant, not in-furrow
pyrethrins + rotenone (Pyrellin) EC 1 - 2 pt 12 hr  
**harvest or grazing of forage or silage