FLEA BEETLES: several species including CORN FLEA BEETLE: Chaetocnema pulicaria, Chrysomelidae

ADULT: Small (1/16 to 3/16 in. long), oval-shaped, coppery brown or dark metallic blue to shiny black beetles with enlarged femora (third leg segment) on rear legs. Adults often jump from plants when approached. The third tarsal segment on all legs is laterally swollen into two lobes with the last (fourth) tarsal segment originating from between the lobes.

EGG: Adults usually deposit eggs singly on weeds in fields or ditch banks.

LARVA: They have grub-like larvae with an enlarged fleshy abdomen, often covered with fecal material. Larvae have three pairs of true legs and grow to 1/8 to 1/4 in. long.

PUPA: The beetles pupate within the soil in a chamber. The pupae are 1/16 to 3/16 in. long and pale white (darkening with age).

GENERATION TIME:

DAMAGE: Corn flea beetles are rare pests in north Florida. Adults are usually the only stage seen on corn. They feed on the leaf surface causing notches, windows and holes in leaves. Large populations can give the crop a bleached appearance which can slow growth and cause leaf wilting. Adults can be destructive during the first 2 to 3 wk. after the crop emerges. Adults can transmit bacterial wilt disease. Damage is worst in fields adjacent to fields of small grains in which corn flea beetles overwintered. Adult flea beetles of several other species can be found on corn throughout the state.  These are often tiny (1/16in.), shiny black beetles that produce window panes on leaf surfaces.  The first three leaves of corn are thought to have some type of antifeedant or toxin that increases beetle mortality.

CONTROL: Cultural control for corn flea beetles involves planting spring corn to fields geographically separated from fields of winter small grains where they overwinter.  Pesticides are available for pre-plant broadcast, at-plant banded and post-emergence foliar applications. Formulations, rates, and pre-harvest intervals of insecticides for flea beetle control are listed below for sweet corn (Table 1) and field corn (Table 2).

Table 1.  Chemical control of flea beetles 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**  
carbofuran (Furadan) 4 F 2.5 fl oz / 1000 row - ft 30 feed forage in-furrow at plant
chlorpyrifos (Lorsban) 4E *** 2 -3 pt 35 fodder, grain; 14 ** adult
chlorpyrifos (Lorsban) 15 G 13.5 lb / 1000 row - ft 35 fodder, grain; 14 ** larvae; broadcast  preplant
cyhalothrin (Karate, Warrior) 1 EC 2.56 - 3.84 fl oz 1  
diazinon (D-z-n) 50 W 1 lb 7  
diazinon (D-z-n AG500) 4 EC 1 pt 7  
diazinon (D-z-n AG600) WBC 12.75  fl oz 7  
esfenvalerate (Asana XL) 0.66 EC 5.8 - 9.6 fl oz 1  
methomyl (Lannate LV) 2.4 EC 0.75 - 1.5 pt 0 ears; 3 forage  
methomyl (Lannate SP) 90 WSP 0.25 - 0.5 lb 0 ears; 3 forage  
methoxychlor 2 EC 2 - 4.5 qt 7 ears; do not feed to livestock  
methyl parathion (Penncap-M) 2 EC 2 - 3 pt 3 ears; 12 forage, grazing  
permethrin (Ambush) 2 EC 6.4 - 12.8 fl oz    
permethrin (Ambush) 25 W 6.4 - 12.8 oz 1  
permethrin (Pounce) 3.2 EC 4 - 8 fl oz 1  
permethrin (Pounce) 25 WP 6.4 - 12.8 oz 1  
permethrin (Pounce WSB) 24.7% WSB 6.4 - 12.8 oz 1  
phorate (Thimet) 20 G 6 oz / 1000 row-ft 30 banded at plant, not in-furrow
pyrethrins + piperonyl butoxide (Pyrenone) 66% L (EC) 2 - 12 fl oz 0  
pyrethrins + rotenone (Pyrellin) EC 1.5 - 2 pt 12 hr  
terbufos (Counter) 15 G 8.0 oz / 1000 row-ft   banded or in-furrow at plant; corn flea beetle
terbufos (Counter CR) 20 G 6.0 oz / 1000 row-ft   banded or in-furrow at plant; corn flea beetle
**harvest or grazing of forage or silage


Table 2.  Chemical control of flea beetles 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**  
carbofuran (Furadan) 4 F 2.5 fl oz / 1000 row-ft 30 feed forage banded or in-furrow at plant
chlorpyrifos (Lorsban) 4E 4 pt or 2 -3 pt 35 fodder, grain; 14 grazing, silage broadcast preplant (larvae) or postemergence (adult)
chlorpyrifos (Lorsban) 15 G 13.5 lb 35 fodder, grain; 14** broadcast preplant; larvae
cyhalothrin (Karate, Warrior) 1 EC 2.56 - 3.84 fl oz 21  
esfenvalerate (Asana XL) 0.66 EC 5.8 - 9.6 fl oz 21  
methomyl (Lannate LV ) 2.4 EC 0.75 - 1.5 pt 3 forage; 21 ears, fodder  
methomyl (Lannate SP) 90 WSP 0.25 - 0.5 lb 3 forage; 21 ears, fodder  
methoxychlor 2 EC 2 - 4.5 qt 7 ears; do not feed to livestock  
methyl parathion (Penncap - M) 2EC 2 - 3 pt 12  
permethrin (Ambush) 2 EC 6.4 - 12.8 fl oz 30 harvest of fodder, grain  
permethrin (Ambush, Pounce) 25 WP 6.4 - 12.8 oz 30 harvest of fodder, grain  
permethrin (Pounce) 3.2 EC 4 - 8 fl oz 30 harvest of fodder, grain  
permethrin (Pounce WSB) 24.7% WSB 6.4 - 12.8 oz 1  
phorate (Thimet) 20 G 6 oz / 1000 row-ft 30 banded at plant, not in-furrow
pyrethrins + rotenone (Pyrellin) EC 1 - 2 pt 12 hr  
terbufos (Counter) 15 G 8.0 oz / 1000 row-ft   banded or in-furrow at plant
terbufos (Counter CR) 20 G 6.0 oz / 1000 row-ft   banded or in-furrow at plant
**harvest or grazing of forage or silage
***check label for other application techniques and rates