﻿38 EIGHTH ANNUAL REPORT 



which lay their eggs unprotected in exposed places ; and wherever 

 there is any great modification of it, we may feel sure that it is for 

 some special purpose, and indicates some other than the ordinary mode 

 of oviposition. Now if we study the structure of the ovipositor of Leu- 

 cania as exhibited on page 3ii, we shall find that it is admirably adapted 

 either to clasping the edge of a grass-blade or of a slender glass-stem, 

 and attaching the eggs in rows therealong, or still better to pressing 

 in between and then widening long and narrow passages, such as oc- 

 cur between the sheath and stalk of grasses and grains, especially 

 just above the joints. It might even be used for splitting the more 

 fragile, yielding and hollow stalks of grain, and of some of the tame 

 grasses, though it evidently could not be inserted into the more solid 

 and pithy stalks of most wild grasses. It is my belief, therefore, that 

 the eggs of the Army Worm are secreted for the most part between 

 the sheath and stalk of its food plants just above the joints. Euro- 

 pean observations do not help us much in forming any opinion; for 

 the eggs of no species of the genus seem to have been observed. 

 The fact is well known, however, that the larvae of those species 

 which frequent more particularly aquatic grasses and reeds, often 

 retreat and live within the stems ; while other insects of the same 

 family, and notably those of the very closely allied genus N'onagria 

 naturally live within the stems of reeds and flags. I find upon exam- 

 ination of such European species as I have been able to observe 

 (j^m/pura AXhm and lithargyria Esp.) that the ovipositor is constructed 

 after the same plan, as are also those of our other American species 

 of the genus ; the difference, when there is any, being in the more 

 pointed upper portion and lesser prominence of the rounder, lower 

 portion of the valve. These facts lend some further weight to the 

 deductions I have drawn. 



There are many good reasons, also, for believing that perennial 

 grasses are preferred by the moth, and that the eggs are seldom con- 

 signed to the stalks of annuals. From about 130 practical and intel- 

 ligent farmers living in different parts of Missouri, to whom I have 

 directly put the question: " What is your experience as to where the 

 eggs of the Army Worm Moth are laid?" the large majority reply 

 that they have made no observations and have no knowledge. A 

 number give it as their opinion (and it is undoubtedly a correct one) 

 that the eggs are laid in grass that has not been pastured and in old 

 meadows; a smaller number that they are laid in oats stubble ; still 

 others that they are laid in old straw stacks; and a few that they are 

 laid in the ground in sheltered and moist places. These opinions are 



