Rono Edwin, Njagi Peter G N, Bashir Magzoub O, Hassanali Ahmed
International Centre of Insect Physiology and Ecology (ICIPE), P.O. Box 30772, Nairobi, Kenya.
J Insect Physiol. 2008 Jan;54(1):162-8. doi: 10.1016/j.jinsphys.2007.08.013. Epub 2007 Sep 6.
The responses of (i) groups of crowd-reared mature males of desert locust, Schistocerca gregaria to a choice of two columns of air, one permeated with different concentrations of phenylacetonitrile (PAN), the major component of gregarious-phase male-produced pheromone, and the other untreated, and (ii) individual crowd-reared mature males of the insect to varying concentration gradients of PAN, were studied in two different types of arena. In the choice assay, locusts preferred to be within PAN-permeated air column at low relative doses of the pheromone, but away from PAN at high relative doses. In the second assay, individual locusts were arrested close to PAN source at low PAN concentration gradients, but away from the source at high concentration gradients. The results are consistent with two reported releaser functions of the adult male-released pheromone that are dependent on different sensory thresholds: arrestment and cohesion at lower relative concentrations and male-male homosexual avoidance at higher relative concentrations.
（i）成群饲养的沙漠蝗（Schistocerca gregaria）成熟雄虫，在两种不同类型的实验场地中，对两列空气的选择反应，其中一列空气渗透有不同浓度的苯乙腈（PAN），这是群居型雄虫产生的信息素的主要成分，另一列未处理；（ii）单独饲养的该昆虫成熟雄虫对不同浓度梯度的PAN的反应。在选择试验中，蝗虫在信息素相对剂量较低时更喜欢待在渗透有PAN的空气柱内，但在相对剂量较高时则远离PAN。在第二项试验中，单独的蝗虫在低PAN浓度梯度下会停留在靠近PAN源的地方，但在高浓度梯度下则远离源。这些结果与已报道的成年雄虫释放的信息素的两种释放功能一致，这两种功能取决于不同的感官阈值：在相对浓度较低时起吸引和聚集作用，在相对浓度较高时起雄虫间同性恋回避作用。
