ENTOMOLOGY. 457 



as hibernating teleutospores. An experiment witli diseased seeds sliowed tliat 

 the disease could be carried by them, and artificial inoculations proved that the 

 fungus could l)e readily conununlcated to the common mallow (Malvu rotuncU- 

 foVn). 



A laboratory method of determining the fungicidal value of a spray mix- 

 ture or solution, D. Reddick and E. Wallace (Abs. in Science, n. ser., 31 

 (lUJO), \o. 803, p. 198). — "The method consists essentially of spraying slides 

 or cover-glasses with a spray substance of a given formula. After proper drying 

 and exposures spores of the pathogen are placed on them in a drop of meteoric 

 water to germinate. This method more nearly simulates natural conditions 

 than that of using a drop of the spray substance direct. Experimental data in 

 connection with the conidia of ycntnria incequalis have been obtained which 

 confirm the fact." 



ENTOMOLOGY. 



Twenty-fourth, report of the state entomologist on the noxious and bene- 

 ficial insects of the State of Illinois, S. A. Forbes {Rpt. State Eat. III., 24 

 (1908), PI). i6'S+A'V/, pis. 8, figs. i«).— Most of the articles which make up this 

 report have been previously noted as Bulletins 104, 107, 108, 112, and 116 of the 

 Illinois Experiment Station (B. S. R., 17, p. 677; IS, pp. 160, 956; 19, p. 554). 



An account is also given of the elm twig girdler {Oherea ulmicola), which 

 has been the source of considerable injury to American elm, particularly at De- 

 catur. It is stated that this beetle has lately been found infesting the cherry 

 and in one case the peach. Attention is directed to the injury of this beetle 

 when, between May 20 and June 15. the tips of small twigs, each bearing a few 

 fresh leaves and cut off squarely at the base, fall from the trees. A careful 

 examination of the stubs remaining on the tree shows a narrow encircling 

 groove or girdle cut through the bark at 2 in. or less from the blunt end, and a 

 small " L "-shaped slit between this girdle and the end of the stub. " Repeated 

 injuries of this description, year after year, give the tree a scrubby and un- 

 wholesome look, and may even kill it eventually, after forcing it to put forth 

 new twigs repeatedly, as the growth of the preceding season is destroyed." 



The female lays her eggs one in a place, usually under a triangular flap 

 of bark made by the intersection of the lines of an " L "-shaped slit. In 1903 

 the girdling of the trees was at its height on May 29 and has been noticed as 

 late as June 10. The earliest date for the hatching out of the larvne is June 

 13 and the latest about June 24. " The slender larva of this beetle lives within 

 the injured twigs, which it burrows lengthwise, pushing its excrement out 

 through small round holes made in the bark for the purpose. . . . The larvae, 

 in various stages of growth, hibernate in their burrows and finish their growth 

 the following spring. . . . Pupation occurs within the burrow, in a cavity 

 shut off in both directions by a firm plug of mingled woody fiber and excre- 

 ment." The earliest date for the appearance of the pui)a is April 16 and the 

 latest is May 22. The beetle has been found to emerge as early as May 10, or a 

 period of about 3 weeks passed in the pupal stage. " The beetles feed on the 

 veins of the leaves, gnawing these away from the under side, thus sometimes 

 making longitudinal slits through the thickness of the leaf." Twigs have been 

 found in which eggs had been laid as many as 8 separate times with the usual 

 number of glrdlings in each case. " Two insect species were found at Decatur 

 preying on the elm twig girdler, one a minute hymenopterous parasite, Eiidci-us 

 lividus, and the other a predaceous grub of a beetle, Cijinatodrra haUcaia." 



In the larval or pupal stage it may be killed by trinuning off and burning 

 the infested twigs in spring at any time before the middle of May. Spraying 

 experiments in which applications of arsenate of lead (12i oz. of sugar of lead 



