Have you seen adult froghoppers in a sugar cane field? If you have, it’s a bad sign because one female adult can hatch up to 300 eggs and if the field is left unattended froghoppers can cause major damage to sugar cane fields. To survive a “froghopper season” the work needs to start immediately after harvesting cane fields. Farmers can request SIRDI’s field personnel to take samples of soils to analyse in their mini-laboratory for the presence of froghopper eggs. These results are usually ready in 2-3 days. If the egg results indicate over 200,000 eggs per acre, a light harrow needs to pass over the sugar cane rows within 2-20 days after harvest. The light harrow makes several cuts on the sugar cane bed; this exposes the eggs to the hot sun to dry. 60-70% of the froghopper egg population can be effectively eliminated using this mechanical method.
Once the rains commence all fertile froghopper eggs remaining in the soil will have the potential of hatching into nymphs also called spittle ,due to the foam like covering that they produce to protect themselves. As nymphs progress through 5 stages, it takes about 30-45 days for them to fully form into an adult. Even at the nymph stage, these cause some damage as they feed off the roots of the sugar cane. This means that the fi eld must be monitored for the presence of nymphs.If the farmer does not identify the problem in his fields, the spittle (nymph) becomes an adult, and at that stage the sugar cane field is in serious trouble! Even though an adult only lives for about 6-9 days, the damage it causes is irreversible.
Once the adult hatches, it immediately starts feeding from the sugars in the plant, injecting toxins into it causing a burnt like appearance; it also starts reproducing, leaving large egg populations for the cycle to start all over again! However, by monitoring and determining the stage of a nymph (by simply breaking the spittle apart) farmers can tell the amount of time they have to implement either a biological or chemical control.
If you need more advice, contact SIRDI at 677-4734.