Management of planthoppers and leafhoppers

The rice planthoppers and leafhoppers are characterized by having two pairs of membranous wings, mouthparts adapted for removing the plant sap, and short bristlelike antennae. There are three stages in the life cycle - egg, nymph, and adult. The nymphs resemble the adults but instead of wings, they have wing pads.

Leafhoppers generally feed on the leaves and upper parts of the plants, while the planthoppers usually infest the basal portions of the plants. However, when planthopper populations become high, they are distributed all over the plant including the panicles.

PLANTHOPPERS

Brown planthopper (BPH) Nilaparvata lugens (Stål) Local name(s) Tagalog: Kayumangging ngusong kabayo Cebuano: Ulmog

Insect characteristics: • Adults are 2.5-4.0 mm long, with either short or long wings. • Hind legs have large and mobile spur. • Food shortage, overcrowding, and unfavorable environment favor the development of long wings. • Capable of long distance migration. • Prefers lowland rice over upland rice.

Life cycle • Eggs are laid in batches inside the leaf sheaths and on the leaf midribs. • Nymphs are brown. • Nymphs molt 5 times within 13-15 days before becoming adults. • It takes 7-9 days for the eggs to hatch into nymphs. BPH population fluctuation In a study conducted by Estoy et al. (2000), BPH population was generally low except in San Mateo, Isabela, where a peak was noted in August-September 1999. However, this was not observed in the following year (Fig. 1).

Knowing the peak of planthopper population in your locality will help you in deciding for proper management options.

Insect characteristics: • Adults are 3-4 mm long, either with short or long wings. • Adults and nymphs resemble BPH but are pale brown with a white mark on its back.

Life cycle • Eggs are laid in batches inside the leaf sheaths. • Nymphs become adults in 16-18 days. • Adults live for about 18-30 days, with females living a little longer than the males.

Life cycle of a brown planthopper.

Tagalog: Puting likod na ngusong kabayo

Life cycle of a whitebacked planthopper.

Fig. 1. Light trap catches of brown planthoppers observed at RhilRice Experiment Stations, 1999-2000.

Where to look for planthoppers • Adults and nymphs congregate on the basal part of leaf sheaths and stems of the plant. • When disturbed, they move to the other side of the tiller or jump. • Their presence can be detected by tapping plants with hand. They