85 



grounds. On investigation it was found that two species were at work, 

 Chcvtocnema denticulata 111. and pidicaria Cr. The former was by far the 

 most abundant species of insect on the entire experimental plat, and 

 was so numerous on broom-corn or Indian millet (Panicum miliaeeum) 

 as to be readily seen at a few paces distant. A smaller number of the 

 latter species was present on the same plat, and both were found in 

 considerably smaller numbers on other species of millet, the injury 

 effected being hardly appreciable. The following were infested in the 

 order named: Panicum capillar e and molle, German millet (Setaria 

 germanica), and pearl millet (Pennisetum spicatum). Adults were in 

 copula for the most part, and many were hidden in the panicles of the 

 flowers, where the grass blade partially concealed them from view. 

 Nearly every leaf of broom-corn miilet was badly injured, damage show- 

 ing in holes varying from the size of a pin prick to long slits a quarter 

 of an inch and more in length. The blades were also badly discolored, 

 this discoloration showing as long white marks placed closely together. 



From adults captured during the first week of July eggs were 

 obtained. The following week the beetles were noticed in decreasing 

 numbers, and search made about the roots at different times till August 

 failed to discover the insect in any stage of growth, although nearly a 

 hundred plants were examined. Careful examination of many plants 

 about the roots showed injury by some larva, particularly just above 

 the roots and at the bases of some of the larger ones. It was very 

 plainly the work of a coleopterous larva, as shown by the nature of the 

 attack and the excrement, but it could not be discovered whether it 

 was the work of Chaetocnema or of the wireworm larva, which was 

 found in some numbers at the same time and which will be mentioned 

 later. 



The following description of the egg of Gluetocnema denticulata is 

 given: Subelliptical, a little larger at one end than at the other. 

 Opaque, pale buff yellow. Surface of moderately small shallow con- 

 cave areas, perfectly hexagonal, with thin edges, like honeycomb, when 

 seen under a high magnifying power ; a few scattered granules. Length, 

 0.74 to 0.76 mm. 5 width, 0.26 to 0.29 mm. 



This flea-beetle, it will be remembered, was mentioned in a paper by 

 the writer presented before the last meeting of the Association of 

 Economic Entomologists (Bull. 9, n. s., Div. Ent., U. S. Dept. Agric, 

 p. 22) as an enemy of the common barnyard grass, Panicum crus-galli, the 

 prediction that it would "probably be found later to be injurious to 

 some of the useful Graminace*" being now verified. We must look for 

 its native larval food plant among our indigenous species of Panicum. 



WIREWORM INJURY. 



July 12, while searching for the larvae of Chaetocnema on the plat of 

 broom-corn millet previously mentioned, larvae and pupae of the wire- 

 worm, Monocrepidius bellus Say, were found at the roots of many plants. 



