Insects which attack plants have a complicated relationship to climate and other environmental factors. Of the climatic factors, temperature and moisture are the most important. Within rather wide temperature limits, moisture is more important than any other environmental factor in crop production. Examining the correlation between average number of blackmargined aphids(y) and total precipitation(x, inch) in June, July, and August during 1988-2000 and plotting the data, we found the relationship was not linear, therefore, Spearman's Rank Order Correlation Coefficient
rs was used to analyze data. There were a medium to strong relationship between aphid's number and precipitation in June, July, and August, respectively. The higher precipitation in June, July, and August, the higher number of aphids it was.
The ESA 2001 Annual Meeting - 2001: An Entomological Odyssey of ESA