xi r 
Much attention lias been called of late to certain root galls 
of trees and shrubby plants, and to the root-rot of softer 
plants of herbaceous growth—effects which are now known to 
be caused by minute slender worms of the same family to 
which the vinegar eel belongs (Anguillulidse). Important 
articles have been published on these animals by Prof. Atkinson, 
of the Alabama Agricultural Experiment Station,* and by 
the Division of Entomology at Washington.f The occurrence in 
Illinois of a species most injurious lias been noticed during the 
last two vears. It infests here hot-house plants of various 
kinds, and also garden vegetables, especially the root crops— 
radishes, beets, and the like. 
In my last report I made mention of a very extraordinary 
outbreak of cutworms, which were during the years 1887 and 
1888 more numerous probably than ever before during the his¬ 
tory of the State; and now, consistently with the usual order 
of events entomological, I have to note the unusual scarcity of 
cutworms during the vear just past and the enormous preva¬ 
lence of disease among them, such that eighty per cent, of our 
breeding-cage experiments came to naught on account of the 
death of the worms from spontaneous disease. Absence from 
the office prevented my studying this interesting occurrence, and 
I can only surmise from the general appearance of the cut¬ 
worms, as reported to me, that the difficulty was bacterial. 
The woolly bark louse of the maple (Plate III., Figs. 4 and 
5) which frequently converts the commonest shade tree of our 
towns into a disgusting nuisance, was last with us in the year 
1885, when its periodical outbreak was suppressed as usual by 
carnivorous and parasitic insect enemies strictly dependent on 
it. Their disappearance in turn has given it fresh opportunity, 
and during the past summer it was not unfrequently seen by 
us on the soft maples throughout Central Illinois in numbers 
insufficient to attract general notice, but still enough to in¬ 
dicate the probability of a fresh uprising. 
There have been three distinct cycles of increase and disap¬ 
pearance of this insect since 1854, when it was first observed 
in the West, these cycles being respectively nine, eight, and 
seven years in length, thus averaging eight years each. Beinp 
now at the beginning of a fresh period, we might not unrea¬ 
sonably expect a reappearance of the insect, apart from specia 
observations of its occurrence. The periods of increase have 
been respectively five, five, and three years, with an average o 
foui’, and we consequently have to anticipate, in accordance 
with this record, a continuance of the approaching outbreak 
for three or four years to come. 
*Bull,No.9(n.s.) Agric. Expr. Station of the Agric. & Meehan. Coll, of Alabama. iScienc* 
Contributions, Vol. I, No. 1.) 
i Bull No. 20, Division of Entomology, U. S. Dept. Agr. 
