Downy mildew is currently only found in the western Pacific and was responsible for severe losses in Queensland until rigorous controls were initiated. Mosaic is a viral disease, whose vectors include Aphis maidis Fitch, was first recognized in Java in 1892 and causes severe stunting in some cases. The most destructive insects of sugar cane are stem-borers, the larvae of several genera of moths. The larvae burrow into the stem and on emergence cause loss of sucrose and weakened stems. Other pests include termites in India and white grubs in Queensland.
Rats are also a problem in many areas, for they eat the cane and introduce pathogens.
The Indian mongoose, Herpestes , was introduced in the West Indies around 1870. Flowering cane is not desirable in commercial plantations because it indicates the end of vegetative growth and sugar production. The greatest advance in sugar cane breeding came in 1888 when it was realized that sugar cane could set fertile seed which could be used to produce better cane varieties. The pollen grain has a short viability, as does the seed. The goal of cane breeding is to produce an economic yield of sugar sustained over several ratoons.