英语语法分析

The population of the spruce budworm, the warbler's favorite prey in North America, has been dropping.

北美莺最喜欢的猎物云杉芽虫的数量一直在下降。

Scientists have now investigated the effects of the spraying of Matacil, one of the anti-budworm agents that is least toxic to insect-pollinators.

科学家们现在已经研究了喷洒灭害威的效果，灭害威是一种抗虫剂，对传粉昆虫的毒性最小。

Is tomato plant the host of the oriental tobacco budworm, Helicoverpa assulta (Guenée)?

番茄是烟青虫的寄主植物吗?。