Baylis M, Rawlings P
Institute for Animal Health, Pirbright, U.K.
Arch Virol Suppl. 1998;14:137-53. doi: 10.1007/978-3-7091-6823-3_14.
Relative abundances of Culicoides imicola at 22 sites in Morocco were compared with climatic variables, altitude and the NDVI (Normalised Difference Vegetation Index, a satellite derived measure of photosynthetic activity) of the same sites. Abundances were negatively correlated with wind speed and positively correlated with the average and minimum NDVI (NDVImin). There were no significant correlations with air or soil temperatures, relative humidity, saturation deficit, rainfall, altitude or mean annual maximum or range of NDVI. The best 2-variable model, which combined wind speed and NDVImin as predictors, explained over 50% of the variance in abundance. It is suggested that wind speed affects the abundance of C. imicola by causing adult mortality while NDVImin provides a measure of the availability of C. imicola breeding sites. Data from 27 sites in Iberia yielded broadly similar results to those found in Morocco although the great abundance of C. imicola at Milfontes (Portugal) could not be accounted for. Several northern sites where the NDVImin is sufficiently high to suggest the presence of C. imicola but where it appears to be absent indicate that there may be a northern limit to the distribution of C. imicola in Iberia that is independent of NDVImin. The potential use of NDVImin to predict the distribution of outbreaks of African horse sickness was investigated using data from the 1989-1990 epizootic in northern Morocco. Within the cluster of outbreaks in Larache province is a corridor of very low NDVImin in which few or no outbreaks were reported.
对摩洛哥22个地点的库蠓相对丰度与相同地点的气候变量、海拔高度和归一化植被指数（NDVI，一种通过卫星测量的光合活动指标）进行了比较。库蠓丰度与风速呈负相关，与平均NDVI和最小NDVI（NDVImin）呈正相关。与气温、土壤温度、相对湿度、饱和差、降雨量、海拔高度或年平均最大NDVI或NDVI范围均无显著相关性。最佳的双变量模型将风速和NDVImin作为预测因子，解释了丰度变化的50%以上。研究表明，风速通过导致成虫死亡影响库蠓的丰度，而NDVImin则反映了库蠓繁殖地的可利用程度。伊比利亚半岛27个地点的数据得出了与摩洛哥大致相似的结果，尽管无法解释葡萄牙米尔丰特斯库蠓数量众多的原因。在几个北部地点，NDVImin足够高表明可能存在库蠓，但实际却未发现，这表明在伊比利亚半岛，库蠓的分布可能存在一个与NDVImin无关的北部界限。利用摩洛哥北部1989 - 1990年动物疫情的数据，研究了NDVImin预测非洲马瘟疫情分布的潜在用途。在拉拉什省的疫情聚集区内，有一条NDVImin极低的走廊，在该区域报告的疫情很少或没有。
