A method for rearing Stenotus rubrovittatus (Matsumura) (Heteroptera : Miridae) by using the spikelets of gramineous weeds as oviposition sites and wheat seedlings for rearing nymphs

The sorghum plant bug, Stenotus rubrovittatus, was reared using wheat seedlings and the spikelets of gramineous weeds. When the spikelets of Poa annua, Digitaria ciliaris, or Eleusine indica were provided as oviposition sites for 10 pairs of S. rubrovittatus along with wheat seedlings as food for 48 h, the average number of nymphs emerging from the spikelets was 88.4, 108.5 and 79.3, respectively; however, only 23.6 nymphs emerged on average when only wheat seedlings were provided. When 10 pairs were reared on wheat seedlings (for food) with spikelets of P annua (renewed every 3 days) as oviposition sites, more than 70% females survived over I month and more than 1,500 nymphs were obtained from the spikelets; however, as the adult density increased, fewer nymphs emerged. The adult eclosion rate was 81.4% when 100 nymphs were reared on wheat seedlings in a rearing cage. Although the eclosion rates decreased as the initial density of nymphs increased, approximately 50% of nymphs reached the adult stage when the initial density in the cage ranged from 500 to 1,500 individuals. These results indicate that wheat seedlings are suitable foods and the spikelets of gramineous plants are suitable oviposition sites for rearing S. rubrovittatus. S. rubrovittatus could be successively reared by using wheat seedlings along with spikelets of gramineous plants (D. ciliaris from summer to fall and P. annita from fall to summer).