attached to the underside of the body close to its hinder end. The 

 ovipositor is then slowly worked down through the surface of the 

 leaf into its substance, the body being gradually lowered during this 

 process, though otherwise the insect appears to be perfectly quiet. 

 Then, by successive contractions, the egg is pushed back under the 

 surface of the leaf. The complete operation requires abouta minute 

 and a half, after which the female usually moves off a short distance 

 and begins feeding. Occasionally the ovipositor becomes so firmly 

 wedged"in the leaf as to hold its possessor prisoner for some time, 

 frequently until death results. The length of time between egg- 

 laying and hatching appears to vary somewhat according to the 

 weather. Eggs laid in early spring hatch in from ten to fifteen days, 

 but during the summer much less time is required. 



When the egg hatches, the youug thrips which somewhat resembles 

 Figure 1, works its way up out of the leaf till it is nearly free, where 

 it remains until its body has sufficiently dried, wheu it pulls itself 

 entirely out and soon begins feeding. When full grown it is about 

 four times as long as when it left the egg, and has now the appear- 

 ance shown in Figure 1 . 



The full grown larvie or young, now seek for some protected place 

 in which to pass through the next stage of life — the pupa. Some- 

 times the place selected is between the stem of the grass and an 

 upper leaf sheath, but usually it is in similar places at the base of 

 the stem near the ground. Here they move about but little, doing 

 no feeding, and assume the form represented in Figure 2. In this 

 condition they remain for a few days, at the end of which time, the 

 outer covering is thrown off and the adult insect appears (Figs. 3 

 and 4.) 



The adult insects.are of two kinds viz. those with wings (Fig 4), 

 and those without (Fig. 3). Over 90% of those of this first spring 

 generation are winged, and are thus able to fly and infest new fields. 

 They appear early in May and at once begin laying eggs for another 

 generation, which passes through the same stages from egg to adult 

 as the first brood, the history of which has just been out- 

 lined, except tliat less time to produce a generation is required as 

 the weather grows warmer. During the season therefore, there is 

 time for eight or nine generations to complete their life histories, 

 each year. As fall approaches, however, fewer winged adults appear, 

 more wingless ones being produced, until in October only about 2% 



