i6o 



NA TURE 



\ June 14, 1906 



necessary preliminary to fruitful university education ; that 

 it is possible to combine literary and scientific training ; 

 that both in secondary and in higher teaching, if the 

 teachers are to stimulate individuality in their pupils, they 

 must be given time and opportunity to cultivate and develop 

 their own ; that examinations may be used to test the 

 power of taking general views, as well as of remembering 

 an infinity of details ; and many other things, which France 

 can teach us. But apart from intellectual profit, there is 

 a moral profit in a meeting of this kind. Blessed are the 

 peace-makers ; and the discovery of unsuspected and deep 

 human sympathies between workers in the same intel- 

 lectual fields, between men and women whose business it is 

 to train up the young minds of their own people, makes 

 for the peace of Europe. 



ECONOMIC ENTOMOLOGY.' 

 (l) CINCE 1867 the State entomologists of Illinois have 

 constantly issued very able reports on noxious 

 and beneficial insects. The first were by Walsh and 

 Le Baron ; the last twelve have been by Prof. Forbes, the 

 writer of the present work. In 1894 he issued the first 

 part of " A Monograph of Insect Injuries to Corn." This 

 extended to some 170 pages, with fifteen plates, and dealt 

 only with those insects that attack the planted seed and the 

 roots of corn of various kinds. This dealt mainly with 

 wire-worm, white-grubs or chafer larvae, ants, aphis, their 

 natural enemies and means of prevention. The second 

 part that has just appeared is very much better than that 

 issued nearly twelve years ago. It treats of the insect 

 injuries to those parts of the corn plant above ground, in- 

 cluding stalk, leaves, and ear. 



A very excellent plan we do not remember having seen 

 before is adopted in the text, namely, that of grouping 

 the insects under the following three headings : — (i) the 

 more important pests ; (2) the less important pests ; and 

 (3) the unimportant species. 



In dealing with the first it is pleasing to note that the 

 insects are dealt with in a strictly practical manner. Such 

 reports as these can well be made to serve a double pur- 

 pose if properly drawn up as this one is, namely, as a 

 reference book for practical men and also for those who 

 are studying the subject from a student's point of view. 

 The coloured plates, of which there are eight, include the 

 army-worm, corn bill-bugs, the chinch bug, the corn-worm, 

 white-grub, the seed-corn maggot, and other well-known 

 corn pests. The plates are good, and show in some cases, 

 not merely the perfect insect, but the whole life-history 

 and the damage produced on the growing plant. 



Among the more interesting sections we find a good 

 account of the damage caused by the chinch bug (Blissus 

 leucoptcrus. Say) and the means of preventing it, of the 

 army-worm (Lcucania unipimclata. Haw.), and of the 

 corn-leaf louse (Aphis maidis, Fitch). In regard to the 

 latter some interesting new observations are recorded, 

 although nothing very definite has been arrived at in 

 regard to the life-history of this corn pest. The author 

 (p. 133) refers to " the failure of all attempts to find or 

 produce a bisexual generation or an alternative food plant 

 of Aphis maidis or to learn how and where it passes the 

 winter." 



Some interesting notes are given on several species of 

 Crambus, called popularly in the States " sod web-worms " 

 or " root web-worms " (Figs, i and 2). Although we have 

 many species of Crambus in Europe, no very material 

 damage has been recorded. In America we learn that 

 " not infrequently these ' web-worms ' become so abundant 

 as to cause brown and deadened spots in a lawn or 

 meadow, sometimes, indeed, deadening the turf as 

 thoroughly as white-grubs or cut-worms can do." Corn 

 seems to be very heavily injured and even completely 

 destroyed over considerable areas in early spring. This is 



J (i) "A Monograph of ihe Intect Injuries to Indian Corn." Part i. 

 By S. A. Forbes. Twenty-third Report of the State Entomologist en the 

 Noxious and Beneficial Insects of the State of Illinois. Pp. 273-|-)ixxiii ; 

 238 Figures and 8 Coloured Plates. (Chicago, 1905.) 



(2) " Df partmental Notes on the Insecis that affect Forestry." By 

 E. P. Stebbing, F.L.S., F.Z.S., F.E.S. No. 3, with Preface and Index to 

 vol. i. Pp. 335-469-1-8 plates. (Calcutta ; Government Printing OfRce, 

 190O.) Price 21. 



an attack we must be prepared for in many localities in 

 this country when grass land is broken up, an unlikely 

 proceeding, however, at the present day with the low price 

 of corn. Probably a good deal of damage is done here 

 now, but has been attributed to other causes. The figures 

 given by Forbes are thus re- 

 produced to give an idea of 

 the larval stage, during which 

 the damage is done. 



In this country, again, we 

 have not observed any in- 

 jurious Syrphidae or hover 

 flies, but we find recorded by 

 Forbes (p. 162) that Meso- 

 gramma polilitm. Say, feed, 

 not on Aphides, but on the 

 pollen and juices of corn and 

 cotton (Ashmead). The whole 

 work is full of interesting and 

 sound material alike to the 

 practical man and student. 

 One point we notice ; the 

 corn-worm or cotton-worm is 

 still called HcUothis armigcr, 

 Hiibner, instead of HeUothis 

 obsoleta, Fabricius, which 

 antedates it. 



.'\ key to the discussion of 

 insect injuries to corn is given 

 which will prove very useful 

 to those studying the subject 

 in America, and even else- 

 where, for where species 

 differ genera often agree in 

 various parts of the world. 

 A very complete bibliography 

 and a copious index complete 

 the work, which is useful to 

 us in many regions other than 

 America. 



(2) This work contains a good deal of useful information 

 and a lot of what appear scrappy notes, which will, how- 

 ever, serve a useful purpose later on. The great difficulty 

 of working at such a subject as the one Mr. Stebbing is 

 engaged upon can only be estimated by those who have 

 attempted the like. 



The economic entomologist is often too apt to jump at 

 specific and even generic determinations, or is loth to 



. I.— The Sod Web-worm 

 (Crambus) web («) contain- 

 ing larva, at base of young 

 corn plant ; d, r, injuries to 

 leaf and stem. 



publish his observations unless the scientific name can be 

 given. Some groups of insects are altnost impossible to 

 name specifically, and many others should only be treated 

 by specialists, who have not always time or inclination to 

 deal with the material sent them. 



NO. 191 I, VOL. 74] 



