BANDED CUCUMBER BEETLE: Diabrotica balteata, Chrysomelidae
ADULT: These small (1/4 to 3/8 in. long), oval-shaped beetles have a dirty yellow to dark green thorax and abdomen, yellow transverse bands across the wing covers (elytra) and red to reddish-brown heads. 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: Small, oval-shaped, pale yellow eggs are found in the soil in clusters of 1 to 12. Larvae emerge in 6 to 8 d.
LARVA: The white, elongate and soft bodied larvae have three pairs of minute legs. Larvae complete development in 15 to 22 d feeding on corn roots. Larvae are indistinguishable from those of spotted cucumber beetle (southern corn rootworm).
PUPA: The white to pale green pupae are found within round cells in soil. Adults emerge in 16 to 20 d.
GENERATION TIME: 35 to 50 d.
DAMAGE: Banded cucumber beetles are found throughout Florida, but are most common south of Tampa. Larvae damage roots, but estimates of yield effects have not been determined for Florida corn. Severe root damage can result in lodging. Adults are common throughout the winter months in south Florida. While preferring to feed on weeds in the genus Amaranthus, adults can cause serious foliar damage to corn and other vegetables. Adults feed on leaves in and out of the whorl and on silks. Adult feeding produces irregular shaped, often elongate holes in young leaf tissue within the whorls. Delayed growth, plant stunting and stand loss can result from heavy feeding damage to whorls of seedlings. Feeding damage to older leaves is evidenced by notched leaves, window paning and irregular patches with only the veins remaining. Silk pruning can result in blanks within the ears. Feeding damage can allow penetration of pathogens, such as Stewart's wilt, which Diabrotica beetles are known to vector. Adults are good fliers and can invade and damage fields quickly.
CONTROL: Several predacious insects and spiders prey on these insects, but migration of large numbers can quickly overwhelm the natural enemy complex. Chemical control of adults is through contact or bait insecticides. These latter type selectively treat the beetles as they eat the baits. Numerous pesticides are labeled for mostly at-plant treatment of cumber beetle larvae. Formulations, rates, and pre-harvest intervals of insecticides for banded cucumber beetle control are listed below for sweet corn (Table 1) and field corn (Table 2).
Table 1. Chemical control of corn rootworms (including cucumber beetles, southern corn rootworms, banded cucumber beetles) in sweet corn | |||
---|---|---|---|
Insecticide, formulation | Rate/acre | Min. days to harvest | Application notes |
carbaryl (Adios, Slam) 13% | 0.25 - 0.75 lb | 0 | SCR adults |
carbaryl (Sevin, Sevin XLR Plus) 4 F, 4 EC | 1 - 2 qt | 2 ears; 48 forage; 14** | CR adults |
carbaryl (Sevin) 80 WSP | 1.25 - 2.5 lb | 2 ears; 48 fodder; 14** | CR adults |
carbaryl () 4 EC | 1 - 2 qt | 2 ears; 48 fodder; 14** | CR adults |
carbofuran (Furadan) 4 F | 2.5 fl oz / 1000 row-ft | 30 feed forage | CR; banded or in-furrow at plant |
chlorpyrifos (Lorsban) 4 E *** | 6 pt | 35 fodder, grain; 14 ** | CR adults; banded or in-furrow at plant or broadcast post-emerge |
chlorpyrifos (Lorsban) 15 G | 8 oz / 1000 row-ft | 35 fodder, grain; 14 ** | SCR larvae; banded or in-furrow at plant |
cyfluthrin (Baythrioid 2) 2 EC | 1.6 - 2.8 fl oz | 0 | CR adults |
cyhalothrin (Karate, Warrior) 1 EC | 2.56 - 3.84 fl oz | 1 | SCR adults |
diazinon (D-z-n AG500) 4 EC | 0.5 - 1 pt | 7 | CR adults |
diazinon (D-z-n AG600) WBC | 6.5 - 12.75 fl oz | 7 | CR adults |
ethoprop (Mocap) 6 EC *** | 1.4 fl oz / 1000 row-ft | CR adults; banded at plant (not in-furrow) or cultivation | |
ethoprop (Mocap) 10 G | 10.5 oz / 1000 row-ft | CR adults; banded at plant (not in-furrow) or cultivation | |
esfenvalerate (Asana XL) 0.66 EC | 5.8 - 9.6 fl oz | 1 | CR, BCB adults |
methomyl (Lannate LV) 2.4 EC | 0.75 - 1.5 pt | 0 ears; 3 forage | CR adults |
methomyl (Lannate SP) 90 WSP | 0.25 - 0.5 lb | 0 ears, 3 forage | CR adults |
methyl parathion (Penncap-M) 2 EC | 1 - 2 pt | 3 ears; 12 forage, grazing | CR adults |
oil (Sun Spray) 7 E | 2 gal / 100 gal water | 0 | CR adults |
oxydemetonmethyl (MetaSystox-R) 2 EC | 1.5 - 2 pt | 7 - 1 app. , 21 - 2 app. | CR adults |
permethrin (Ambush) 2 EC | 6.4 - 16.0 fl oz | 1 | CR adults |
permethrin (Ambush) 25 WP, WSB*** | 6.4 - 16.0 oz | 1 | CR adults |
permethrin (Pounce) 25 WP | 6.4 - 12.8 oz | 1 | CR adults |
permethrin (Pounce) 3.2 EC | 4 - 8 fl oz | 1 | CR adults |
phorate (Thimet) 20 G | 6 oz / 1000 row-ft | 30 | CR adults; banded at plant (not in-furrow) or cultivation |
pyrethrins + piperonyl butoxide (Pyrenone) 66% L (EC) | 2 - 12 fl oz | 0 | SPCB adults |
pyrethrins + rotenone (Pyrellin) EC | 1.5 - 2 pt | 12 hr | cucumber beetle |
tefluthrin (Force) 3 G | 4 - 5 oz / 1000 row-ft | SCR; banded or in-furrow at plant or cultivation | |
terbufos (Counter) 15 G | 8.0 oz / 1000 row-ft | 30 forage, grazing | CR adults; banded or in-furrow at plant or cultivation |
terbufos (Counter CR) 20 G *** | 6.0 oz / 1000 row-ft | 60 ears; 30 forage, grazing | CR adults; banded or in-furrow at plant or cultivation |
CR = corn rootworms, SCR = southern corn rootworm, BCB = banded cucumber beetle, SPCB = spotted and 12-spotted cucumber beetle | |||
**harvest or grazing of forage or silage | |||
***check label for other application techniques and rates |
Table 2. Chemical control of corn rootworms (including cucumber beetles, southern corn rootworms) in field corn | |||
---|---|---|---|
Insecticide, formulation | Rate/acre | Min. days to harvest | Application notes |
carbaryl (Adios, Slam) 13% | 0.25 - 0.75 lb | SCR adults | |
carbaryl (Sevin, Sevin XLR Plus) 4 F, 4 EC | 1 - 2 qt | 48 fodder, grain; 14** | CR adults |
carbaryl (Sevin) 80 WSP | 1.25 - 2.5 lb | 48 fodder, grain; 14** | CR adults |
carbofuran (Furadan) 4 F | 2.5 fl oz / 1000 row - ft | 30 feed forage | CR adults; banded or in-furrow at plant or post emergence side dress |
chlorpyrifos (Lorsban) 4 E*** | 2.4 fl oz / 1000 row-ft or 1 - 2 pt | 35 fodder, grain; 14 grazing, silage | CR larvae; banded and in-furrow at plant or broadcast post-emerge |
chlorpyrifos (Lorsban) 15 G | 8 oz / 1000 row-ft | 35 fodder, grain; 14** | SCR larvae; banded or in-furrow at plant or at cultivation |
cyhalothrin (Karate, Warrior) 1 EC | 2.56 - 3.84 fl oz | 21 | SCR adults |
dimethoate (Dimate, Dimethoate 400) 4 EC | 0.67 - 1 pt | 14 | CR adults |
esfenvalerate (Asana XL) 0.66 EC | 5.8 - 9.6 fl oz | 21 | CR adults |
ethoprop (Mocap) 6 EC | 1.4 - 2.9 fl oz / 1000 row-ft | CR adults; banded at plant or at cultivation, not in-furrow | |
ethoprop (Mocap) 10 G | 10.5 - 21.5 oz /1000 row-ft | CR adults; banded at plant or at cultivation, not in-furrow | |
ethyl parathion (Parathion) 8 EC | 0.75 pt | 12 | CR adults |
methomyl (Lannate LV) 2.4 EC | 0.75 - 1.5 pt | 3 forage; 21 ears, fodder | CR adults |
methomyl (Lannate SP) 90 WSP | 0.25 - 0.5 lb | 3 forage; 21 ears, fodder | CR adults |
methyl parathion (Penncap -M) 2 EC | 1 - 2 pt | 12 | CR adults |
oil (Sun Spray) 7 E | 2 gal / 100 gal water | CR adults; early spring, summer | |
permethrin (Ambush) 2 EC | 6.4 - 12.8 fl oz | 30 harvest of fodder, grain | CR adults |
permethrin (Ambush) 25 W | 6.4 - 12.8 oz | 30 harvest of fodder, grain | CR adults |
permethrin (Pounce) 25 WP; WSB*** | 6.4 - 12.8 oz | 30 harvest of fodder, grain | CR adults |
permethrin (Pounce) 3.2 EC | 4 - 8 fl oz | 30 harvest of fodder, grain | CR adults |
phorate (Thimet) 20 G | 6 oz / 1000 row-ft | 30 | CR adults; banded at plant or cultivation, not in-furrow; not popcorn |
pyrethrins + rotenone (Pyrellin) EC | 1 - 2 pt | 12 hr | cucumber beetles |
tefluthrin (Force) 3 G | 4 - 5 oz / 1000 row-ft | SCR; banded or in-furow at planting or cultivation | |
terbufos (Counter) 15 G | 8.0 oz / 1000 row-ft | CR adults; banded or in-furrow at plant or cultivation | |
terbufos (Counter CR) 20 G | 6.0 oz / 1000 row-ft | CR adults; banded or in-furrow at plant or cultivation | |
CR = corn rootworms, SCR = southern corn rootworm | |||
**harvest or grazing of forage or silage | |||
***check label for other application techniques and rates |