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 and What Should Never Be" was performed live at Led Zeppelin concerts between 1969 and 1973. A live version taken from a performance at the Royal Albert Hall in 1970 can be seen on the "Led Zeppelin DVD". Another was included on disc two of the live triple album "How The West Was Won". Two more versions were included in BBC Sessions. 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