comparison of the suitability of four commercial pistachio cultivars to the pistachio green stink-bug, brachynema germari, under the laboratory conditions

The pistachio green stink-bug, brachynema germari kolenati (hem.: pentatomidae), is an important pest of pistachio in iran. in this research, the effects of four commercial pistachio cultivars that are commonly grown in iran including kaleghochi, ahmadaghaii, ohadi and akbari were evaluated on the biology (developmental time, mortality rate, longevity) and demographic parameters of b. germari under the laboratory conditions at 27.5±1°c, 65±5% rh and 16: 8 (l: d) h, during 2016-2017. the longest and the shortest immature development times were observed on akbari (38.11 days) and kaleghochi (25.54 days) cultivars, respectively. the highest and the lowest mortality rates of immature stages were on akbari and kaleghochi cultivars, respectively. the gross (grr) and net reproductive rates (r0) were significantly lower on akbari compared to other cultivars. the intrinsic rate of increase (rm) and the finite rate of increase (λ) were significantly different among the studied cultivars. the calculated rm values were 0.04, 0.06, 0.07 and 0.08 (day^-1) on akbari, ohadi, ahmadaghaii and kaleghochi cultivars, respectively. also the lowest value of λ was observed on akbari cultivar that was significantly different from the other three cultivars. moreover, the longest mean generation time (t) was also observed on akbari cultivar. the reproductive parameters were also significantly different on the studied cultivars and the lowest and the highest values of all parameters were observed on akbari and kaleghochi cultivars, respectively. according to these results, it was concluded that among the studied cultivars, akbari was the less suitable cultivar for pistachio green stink-bug compared to others and it can be used in ipm of this pest.