162 EXPERrMrENT STATION KECOED. [Vol.38 



10 days in September. The average period required for the development of 

 tlie larva was 267 days, tlie maximum 35G days and the minimum 179 days, 

 during which time 3 molts were passed. The prepupal stage was found to vary 

 from 4 to 7 days and the average duration of the pupal stage was 21.5, the 

 maximum being 26 and the minimum 17 days. The average normal egg-to- 

 adult period based upon 14 complete records of single individuals was 306 days, 

 the maximum 395 days and the minimum 212 days. 



The adults differ from many .species of the genus in that they are very 

 general feeders, there being few plants that they will not touch. Experi- 

 ments have .shown that ordinarily the adults are only attracted to light during 

 their flight and before they have settled on foliage to feed, i. e., from 4 to 7.30 

 p. m. In order to have any practical efficiency in attracting the adults of 

 this species the lights must be placed close to the ground and started imme- 

 diately at dusk, while the beetles are flying. 



IMention Is made of three species of birds that are important enemies of 

 white grubs in Porto Rico and of a predacious wireworm {Pyrophorus liimi- 

 nosus). Their parasites include six scoliids (Elis sexcincta, E. xanthonotus, 

 Campsomeris dorsata, C. trifaciata, C. pyrura, and ScoUa atrata), and two 

 tachinids (Cryptomeigenia aurifacies and Eutrixoides jonesii). The eggs are 

 attacked by mites and nematodes. 



A bibliography of 36 titles is included. 



White grub investigation. — A brief report of progress, A. Gibson (Agr. 

 Gaz. Canada, 4 {1911), No. 7, pp. 554-556, figs, g).— A brief statement of prog- 

 ress in the work on white grubs. 



Existence of many varieties and races of coccobacilli in the natural septi- 

 cemias of the cockchafer, A. Paillot (Compt. Rend. Acad. Sci. [Paris], 163 

 (1916), No. 19, pp. 581-534). — The author recognizes four types of Bacillus 

 melolonthce, one representing the variety to which he gives the name B. melo- 

 lonthcc Uqtiefacicns, and the other three, the variety B. melolonthw nonliqne- 

 faciens. Studies of a bacterial disease of the cockchafer in this country by 

 Northrup have been noted (E. S. R.. 32. p. 61). 



New microbe parasites of the cockchafer, A. Paillot (Compt. Rend. Acad. 

 Sci. [Paris], 163 (1916), No. 24, pp. 772-774; abs. in Jour. Roy. Micros. Soc, 

 No. 2 (1917), p. 249). — While the septicemia caused by coccobacilli appear to 

 be the principal cause of the natural mortality in cockchafers, it is not always 

 possible to obtain pure cultures of the causative coccobacillus from the blood of 

 affected individuals. In fact, in some 30 per cent of the cases a secondai-y 

 infection accompanies the coccobacillemia. Three different associated diseases 

 have been studied and all found in cockchafers from the Plateau of Sathonay. 

 They are due (1) to BaciUns melolonthw nonliqucfaciens /3 and a gram-positive 

 diplococcus (Diplococcus melolonthce) ; (2) to B. mclolontha; liqvefacicns and 

 a gram-positive diplobacillus (Diplobacillus mclolontha;) ; and (3) to the same 

 coccobacillus and a large sporulating bacillus, described as new under the 

 name Bacillus hoplostcrmts, which takes Gram's stain poorly. B. hoplosternns 

 is very pathogenic for the cockchafer and the caterpillar of Yanessa urticce, but 

 does not kill the caterpillar of the gipsy moth regularly even after many 

 passages. 



The coccobacilli of the cockchafer. — Their pathogenic action on sorce 

 macrolepidopterous caterpillars, A. Paillot (Compt. Rend. Soc. Binl. [Paris]. 

 79 (1916), No. 20, pp. 1102, llOS; abs. in Rev. Appl. Ent., Ser. A, 5 (1917), No. 

 S, p. 134)- — This relates to the investigations above noted. 



New microbe parasites of the cockchafer. — Pathog'enic action on the 

 caterpillars of Vanessa urticae and Lymantria dispar, and the silkworm. 



