## 2 Materials and Methods
### Honeydew and Its Effects on Egg Parasitism  
To compare honeydew production by BPH on IR62 and IR64, we first conducted a greenhouse experiment. Plants (IR62 or IR64) were sown to pots of 5 \(\times\) 5 cm (H \(\times\) diam) with zero-added nitrogen or with nitrogen equivalent to 150 kg ha\({}^{-1}\). At 14 DAS, plastic chambers (5 \(\times\) 10 cm: H \(\times\) diam) were placed around the base of each plant. Each chamber had a hole at the base and at the top, through which the plant passed, with a cotton plug used to seal the top hole around the plant [28]. Filter paper (Whatman No. 1) treated with bromocresol green, was placed at the base of each chamber. Bromocresol green indicates honeydew as blue-rimmed, alkaline spots and white-rimmed, acidic spots. The blue spots represent phloem-derived honeydew and the white spots, xylem-derived honeydew [30]. At 15 DAS, a single, pre-starved (2 h) gravid brachyproteins female was confined to each chamber. The planthoppers were allowed to feed for 24 h after which the filter papers werecollected and photographed with a Nikon D90 (12.3 megapixel) digital camera (Nikon Corp., Tokyo, Japan) on an illuminated bench. The areas of all spots were measured from the images using ImageJ-J version 1.48 (National Institute of Health, Bethesda, MD, USA). The bioassay was replicated five times (i.e., 2 varieties \(\times\) 2 nitrogen levels \(\times\) 5 replicates = 20 pots).  
We assessed the influence of honeybee from the different varieties on parasitism in the field plots. Sentinel plants infested with BPH eggs were prepared as described above. After the adult BPH had been removed, honeybee was removed from the plant surfaces by rinsing and wiping the plants with a wet paper towel. Plants were divided into three groups. The first group had honeybee collected from BPH feeding on the same variety applied to the stem surface of each plant (e.g., host plant = IR62, honeybee = IR62). A second group of plants had honeybee collected from BPH feeding on a different variety applied to the stem surface (e.g., host plant = IR62, honeybee = IR64). The honeybee that was applied to the plants was collected by attaching parafilm sachets [29] of 5 \(\times\) 5 cm (H \(\times\) W) with five gravid females inside, to plants of either IR62 or IR64 under each nitrogen regime. After 36 h, the honeybee was removed from the parafilm using micropipettes and was applied to the stem surface of the sentinel plants. During the dry season, 12 \(\mu\)L of honeybee was applied. The honeybee was dripped over the base of the plants and allowed to air dry. A third group of plants had no honeybee applied to the surfaces (i.e., honeybee was wiped off). Plants (with and without honeydew) were then exposed in the corresponding subplots (i.e., matching variety and nitrogen level). After 4 days, the plants were collected and processed as described above. The experiment was replicated 6 times each season (i.e., 3 treatments [with honeydew from planthoppers on the same variety, with honeydew from planthoppers on a different variety, and without honeydew] \(\times\) 2 varieties \(\times\) 2 nitrogen levels \(\times\) 6 replicates = 72 exposed plants per season).