XI 



:he first imago* (a female) emerged October 9; a male, October 10. 

 October 16, two more females appeared and another male; October 

 23, another male; October 26, three males and a female; October 

 27, one female and three males. On a final search in the cage, 

 made November 12, a female was found dead, with eggs near her. 

 Compared with our previous record, as presented in the Fifteenth 

 Report and in my Office Bulletin No. 3, these data merely bring 

 the appearance of this autumnal brood about ten days earlier. An 

 attempt to secure fertilized eggs and rear larvae from the imagos 

 hatched as above, failed,— probably because the small number of 

 specimens reared and their scattered appearance prevented copulation. 



Another dipterous insect (a tipulid larva), brought to the 

 front in a new relation by the drouths of 1886 and 1887, was 

 first obtained by us from meadows in Edw^ards county in the fall 

 of 1886, w^here it had shared largely, at least, in the destruction 

 of a field of clover. The feeding habits of this species, and the 

 extent of its injuries were made out by us in 1887, as will appear 

 in the body of this report. 



The same conditions which encouraged the multiplication of 

 web worms in 1887 and 1888 gave rise during the former year to 

 an extraordinary number of white grubs, especially in lawns. 

 Experiments made at this time on the University lawn demonstrated 

 the possibility of killing the grubs in the earth by a free use of 

 the kerosene emulsion, but at an expense considered excessive by 

 the horticultural foreman. This standard species is rapidly rising 

 in importance as a corn insect in Central Illinois, evidently breed- 

 ing freely in corn, as shown by our own observations and by cor- 

 respondents' reports. A general destruction of the beetles by 

 light-traps will probably be necessary in some of the worst infested 

 districts. 



Among minor injuries by beetles we noticed a habit— not hitherto 

 reported — of one of the lady bugs, Anaiis 15-pundaia, which was re- 

 peatedly observed burying itself in the pulp of ripe cherries on 

 the trees. 



Another coleopterous species detected in a new mischief is the 

 pale striped flea beetle, Systena hlanda, sent us from Southern 

 Illinois as the most common and destructive melon insect. 



From granaries and elevators at Shawneetown, at Albion, and in 

 Central Illinois, I received during the fall of 1887 several lots of an 

 insect larva reported as destructive to stored grain. This proved to 

 belong to a species of beetle ( Tenebrioides mauritanica ) of the 

 family Trogositidae, mentioned in the earlier reports of this series 

 by both LeBaron and Thomas, and by them regarded as carnivo- 

 rous only — a conclusion in which they followed eminent European 

 authorities. Our observations show, however, that this supposi- 

 tion is an error, as the larvae placed in confinement in boxes of 



