请问大家，这个程序总报错，但是我不清楚错在哪里。谢谢。

> library(randomForest)
randomForest 4.6-7
Type rfNews() to see new features/changes/bug fixes.
Warning message:
package ‘randomForest’ was built under R version 3.0.2
> insect <- read.csv("d:/data/insects.csv", header = TRUE)
> insectRF1 <- randomForest(insect[,c('L1','L2','L3','L4')], insect[,'species'], importance=TRUE, ntree=10000)
> new.data <- data.frame(L1=20, L2=50, L3=30, L4=20)
> predict(RF1, new.data, type="prob")
Error in predict(RF1, new.data, type = "prob") : object 'RF1' not found


实际的附件后缀是csv,但是论坛上传限制，所以我只能传上xlsx.