Agonopterix alstroemeriana with the dry weight of the leaf. However, oviposition was not correlated positively with the concentration of alkaloids in the poison hemlock, which varies widely among individual plants. Therefore, it is difficult to predict whether increased alkaloids in the plant would increase or decrease the use of the hemlock moth as a biological control. The effects that the alkaloids in "Conium maculatum" cause on the moth, both physiologically and behaviorally, are relatively unknown. Persons interested in the biological control capabilities of "A. alstroemeriana" see behavioral dependency on the host plant as an asset when using this moth as a biological
What Is and What Should Never Be What Is and What Should Never Be "What Is and What Should Never Be" is a song by English rock band Led Zeppelin. It was written by Jimmy Page and Robert Plant and was included as the second track on "Led Zeppelin II" (1969). "What is and What Should Never Be" was one of the first songs on which Page used his soon-to-become trademark Gibson Les Paul for recording. The production makes liberal use of stereo as the guitars pan back and forth between channels. Robert Plant's vocals were phased during the verses. Record producer Rick Rubin has remarked, "The