Pests


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Sugarcane Borer (Diatraea saccharalis)

The sugarcane borer, Diatraea saccharalis, is one of the most important of the above-ground pests of sugarcane in Florida. Although this insect's principal host is sugarcane, other grasses including rice and corn have been reported as alternative hosts.

It causes damage by tunneling within the stalk, which reduces stalk weight and sucrose yield. Also, the borer's tunneling into the stalk allows secondary invaders like fungal, bacterial, and viral disease organisms to enter. One investigation showed that plants with bored internodes produce 45% less sugar than undamaged ones. Additionally, the weakened stalks are more subject to breaking and lodging.

Identification

The life cycle of the sugarcane borer includes four main stages of development - the egg, larval, pupal and adult stages. The larvae molt 5 to 7 times depending upon climatic conditions during their of growth. The adult is nocturnal a straw-colored moth that is about one inch across its spread wings.The forewings are marked with black dots in a V-shaped design.

Females lay approximately 200 to 300 creamy white eggs in clusters of 25 to 30 on on the undersides of a leaves in the upper half of the sugarcane plant canopy. Yellowish-white, brown-spotted caterpillars (larva) are the most familiar stage and cause the damage to sugarcane.

Adult 

adult larva looks like a moth  

Damage

chew marks dark brown from larva eating  

Larva

wormlike larva  

Egg mass

white spot on leaf  

 

Control

An integrated pest management (IPM) program consisting of several well-balanced components will provide effective borer control and increase profits without harming the environment.

The most important part of an IPM program for sugarcane borers is regular scouting. Suggested control options include biological agents, planting varieties that exhibit resistance to infestation and damage, planting borer-free seed pieces and insecticides

Summarized from EDIS document 'SC007 Sugarcane Borer in Florida' for more information please refer to the full length document at http://edis.ifas.ufl.edu/SC007.

Lesser Cornstalk Borer Elasmopalpus lignosellus

The larva of the lesser cornstalk borer (Figure 1) is a slender brown worm with creamy white to bluish-green bands 3/4 to 1" long when full grown The larvae bore into young plants at or below the soil surface and usually cause a "dead-heart" similar to the sugarcane borer or wireworms. When they feed at or below the growing point, damage above the growing point appears as rows of holes in emerging leaves.

The larvae construct a tubular burrow in the soil extending outward from the cane plant. The burrow consists of soil particles which the borer webs together with silk. The larva pupates in this burrow and transforms into a small moth. The presence of these silk tubes and/or a small circular entrance hole distinguishes deadhearts caused by lesser cornstalk borers from those caused by wireworms.

The life cycle of the lesser cornstalk borer ranges from 38 to 65 days. There is considerable overlapping of generations with no sharp seasonal breaks in populations, although infestations during late summer may be uncommon.

Most damage from this pest occurs to young plants during warm, dry periods. Ratoon cane usually recovers better from lesser cornstalk borer attack than young plant cane.

Although there are parasites of the lesser cornstalk borer, the protection given by the silk tube may make these inefficient as biological control agents.

Green white wormlike larvae  

 

two  yellow orange looking insects  

 

Control:

Carbofuran (Furadan 4F) has recently become available for use on lesser cornstalk borer in sugarcane. A commercial pheromone is available which can be used in traps to identify when and where populations of the lesser cornstalk borer are building up. 

Adapted from ‘SC014 Miscellaneous Insect Pests of Florida Sugarcane.