ASTER LEAFHOPPER: Macrosteles fascifrons, Cicadellidae

ADULT: Newly emerged adults are bright green, but the wings become greenish-gray to brown and the abdomen becomes yellowish-green after a few days. The wings overlap over the abdomen. The area above the mouthparts and between the compound eyes have three to four rows of transverse blackish bars extending toward the center of the face and one bar running longitudinally down toward the mouthparts from near the ocelli. Females have a 9 d pre-oviposition period and produce an average of 40 eggs.

EGG: Eggs are inserted singly or in rows of four along leaf margins. Nymphs emerge in 4 to 8 d.

NYMPH: They have a dull to bright medium green body with reddish-brown to blackish compound eyes. Black bars on face first appear in 4th instar. Five nymphal stages are completed in 14 to 26 d.  There is no pupal stage in cicadellids.

GENERATION TIME: 18 to 34 d.

DAMAGE: While not common in Florida, the aster leafhopper is one of the most common leafhoppers collected in U.S. corn. They transmit the semipersistant maize chlorotic dwarf virus and the persistent diseases maize rayado fino maya virus (MRFM), corn stunt spiroplasma (CSS) and maize bushy stunt phytoplasma (MBSP). These diseases are rare, but 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 aster leafhopper control are listed below for sweet corn (Table 1) and field corn (Table 2).

Table 1.  Chemical control of aster 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**  
cyhalothrin (Karate, Warrior) 1 EC 2.56 - 3.84 fl oz 1  
oxydemetonmethyl (MetaSystox-R) 2 EC 1.5 - 2 pt 7 - 1 app., 21 - 2 app.  
permethrin (Ambush) 2 EC 6.4 - 16 fl oz 1  
permethrin (Ambush) 25 WP 6.4 - 16 oz 1  
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