54 



BULLETIN 416^ TJ. S. DEPAETMENT OF AGEICULTURE. 



COLEOPTERA. 



COCCINELLIDAE. 



In 1893 Morgan recorded the predatory work of Pentilia sp., 

 which was very effective against mites at Baton Rouge, La. Titus 

 states that several lady-beetles were observed by him in 1905 feeding 

 on the red spider. In 1906, at Washington, D. C, Chittenden (1909) 

 fomid (Scymnus) Stethorus punctum an active enemy of the red spider 

 on Gymnocladus. Stethorus punctum was also recorded in 1909 by 

 Weldon as one of the principal red-spider enemies in Colorado. 

 Worsham (1910) states that Stethorus punctum was the only preda- 

 cious species observed in Georgia in the case of the cotton red spider. 

 In the Sacramento Valley of California, Parker (1913) found Stethorus 

 nanuSy S . marginicollis , and Pentilia sp. present in small numbers 



Fig. 16. — Stethorus punctum, an enemy of the red spider: a, Egg; 6, larva; c, pupa; d, adult. All 

 greatly enlarged, a, b, c, redrawn after Weldon; d, Webster. 



in mite colonies. Ewing (1914) found the larvae of Stethorus punc- 

 tum in the Willamette Valley, Oregon, where he says they were vora- 

 cious red-spider enemies. These coccineUids have been known as 

 red-spider enemies for some time, and occur over a large part of the 

 United States. 



Stethorus punctum Le Conte (fig. 16). — This is probably the most 

 effectual coccinellid enemy of the red spider. We have seen it so 

 extremely abundant on infested jack beans and jump-vine leaves 

 that the red spider was quickly exterminated. On these host plants 

 as many as a dozen larvae and a dozen pupae have been seen on a 

 single leaf. This is the same species as that observed by J. C. Duffey 

 (1891) to exterminate vast colonies of the red spider on Manihot, 

 Ficus, Morus, Tilia, and Ipomoea at St. Louis in 1891. Such striking 



