292 



"(3) The season proved favorable ::or the development of the 

 blight, Avhich appeared in the experimental field abont the middle 

 of June and did serious damage for the next six weeks. 



"(4) The sprayed vines showed much less injury than their un- 

 sprayed companions, remaining green after the others were dead. 



'•(5) The ci'op was harvested August 22, and the product of 12^ 

 feet of the sprayed part of each i-ow was compared with the product 

 of an equal distance of the unsprayed portion of the same row.'" 



" So far as a single experiment can be relied upon, the results seem 

 to indicate tlie correctness of the following provisional conclusions: 



"(1) That a large proportion of the injury done by the potato rot 

 can be j^revented by spraying the vines with the Bordeaux mixture. 



'*(2) That this treatment apparently diminishes the amount of 

 scab alTecting the tubers. 



"(3) That l)y adding London purple to the mixture the same 

 treatment may be made elfective in preventing the injuries of both 

 the rot and the Colorado potato beetle.'' 



BULLETIN Vol. L No. 1 (TECHNICAL SERIES*), OCTOBER, 1889. 



On the preparatory stages of the 20-spotted i.ady-bird (Psyl- 

 i.OBORA 20-macttLata, Say) , C. M. Weed, M. S. (pp. 3, 4), ( illus- 

 trated ^ — Descriptions and figures of the larva and pupa of this 

 insect, with observations made by the author in the fall of 1889. 



Sti'dies im pond life, C. M. Weed, M. S. (pp. 4-17), ( illus- 

 trated ).^The results of observations are given under the following 

 heads: (I) On the life history of the large typha -borer (Arsama 

 ohliquata, G. and U.). (2) On the life history of the toothed-horned 

 fish fly {Chaul'iodes rasfricornis, Eamb.). (3) On the life history 

 of the sagittaria curculio {Listronotus latiusculus, Boh.). (4) On 

 the feeding habits of the lesser water-bug {Zaitha fumhiea^ Say). 

 (5) On the feeding habits of the midulating back swimmer {Noto- 

 nectn intdulata. Say). ((>) An aquatic leaf beetle {Donacia subfilis, 

 Kunzc). (7) An aquatic lady-bird {Illppodamia TS-punctata^ 

 DeG.)! (S) On the eggs of the giant water-bugs {Belostoma ameri- 

 canum, Leidy, and. Benacus griseus. Say). 



A. partial BlIiLIOGRAPHY OF INSECTS AFFECTING CLOVER, C. M. AVeED, 



M. S. (pp. 17-45). — In view of the injury inflicted on the clover 

 crop in Ohio by the midge, clover-root borer, and other insects, the 

 entomologist of this Station has begun an extended investigation 

 of the insects atfecting this plant, and as a basis for future work has 

 prepared the partial bibliography published in this bulletin. A 

 list of 82 species of insects known to attack clover is also given. 



* " This series of the hulletins of the Ohio Agricultural Experinieut Station 

 is intended to embody the technical results of the work of the Station. It is 

 not expected that these results will be of direct service to farmers in general, 

 but it is lioped that they may be found useful l»y workers in nther Stations, 

 and tlnis iiidii-ci-tiv serve the cause of agriculture."' 



