Oviposition Behavior of the Rice Brown Planthopper, Nilaparvata lugens (Stål), and Its Electronic Monitoring

Oviposition behavior of Nilaparvata lugens (Stål) (Homoptera: Delphacidae) on rice, Oryzae sativa L., was monitored using a videocamera and an AC (alternating-current) electronic measuring system. Oviposition by N. lugens always took place during stylet penetration into the plant. After penetration of the ovipositor, there were three specific ovipositional sequences observed; sawing insertion of the ovipositor, release of an egg in the plant, and partial or complete withdrawal of the ovipositor from the plant. Distinctive waveforms were recorded in correlating with these events. From a sequence of waveform patterns, it was possible to determine the number of eggs and egg masses laid inside the plant tissue and the duration of oviposition behavior. Waveform analysis revealed that N. lugens laid an egg mass consisting of on average 5.7 eggs. This occurred 4.3 min after a period of about 6.4 min of stylet penetration, and this sequence was repeated several times in 24 h. Electrical and/or tethering effects on oviposition appear to be negligible within 24 h of recording.