650 EXPERIMENT STATION RECORD. 



It has attained its standing as a destructive pest because of its injurious work 

 on the raspberry and blackberry. The injuries arise from the long series of 

 punctures which it produces in canes during the process of egg laying. As a 

 result of the rupturing of woody tissues the cane splits at the point of injury 

 and becomes so weakened that it eventually breaks down from the weight of 

 the upper growth or from twisting by the wind. 



These tree crickets have a number of natural enemies, the more common 

 and eflacient being egg parasites of which there are S species. These include 3 

 chalcidoids and 5 species of proctotrupoids, namely, MacroriJcya cecanthi, 

 Anastatiis (Antigaster) mira'biUs, Polyncma hifasciatipenne, Teleas (?), Calo- 

 teleia sp., Baryconus cecanthi, Caciis oecanthi, and Idris sp. Of the three species 

 discussed 0. nigrieornis appears to be the most subject to parasitism. 



In regard to preventive and remedial measures it is stated that cultivation 

 to destroy foreign vegetation, as weeds and brush, about and in plantings of 

 fruit, and to keep the ground about trees and vines clean is an efficient meas- 

 ure for the prevention of damage. "While the susceptibility of these insects 

 to arsenicals has not been conclusively demonstrated it is believed that the 

 numbers of the tree crickets are reduced by summer applications of these 

 poisons. Raspberry canes showing extensive oviposition should be removed in 

 the course of winter and spring pruning and burned to destroy the eggs con- 

 tained in them. 



Tree crickets of garden and orchard, F. H. Hall (New York State Sta. Bid. 

 388, popular ed. {1914), PP- 8, pU. 4> fiff^- 3)- — A popular edition of the above. 



The Acridiidse of Minnesota, M. P. Somes (Minnesota Sta. Bui. 14I [1914), 

 pp. 7-100, pis. 4, figs. 11). — A synopsis of this order, with tables for the sepa- 

 ration of the forms described as occurring in Minnesota. A brief bibliography 

 is appended. 



The tarnished plant bug (Lygus pratensis), C. R. Crosby and ^I. D. Leonard 

 {Neic York Cornell Sta. Bid. 346 {1914), pp. 463-526, pis. 6, figs, fl).— This sum- 

 marized account of the present knowledge of L. pratensis includes the results of 

 observations and experiments commenced by the authors in 1911. Some 50 

 plants are mentioned as being injured by this plant bug. 



In New York as a rule the pest hibernates in the adult stage. Oviposition 

 was observed on August 10, 1898, by Slingerland, who found about 10 days to be 

 required for the incubation of the egg. Five uymphal stages are described and 

 illustrated. It is stated that Haseman (E. S. R., 29, p. 354) has found 25 to 30 

 days to be i-equired in September and October for the completion of the life 

 cycle, thus indicating that there are four or five annual generations. The insect 

 has but few natural enemies. The eggs, however, are destroyed to a slight 

 extent by the minute mymarid parasite Anagrus ovijentatus. 



The greatest injury by this insect appears to be caused to peach nursery 

 stock. Nursery stock thus attacked presents a dwarfed and bushy appearance, 

 due to the killing of the terminal buds of both the laterals and the main shoot 

 by the feeding punctures of the adults in late June and early July. Observa- 

 tions which extended over the last two years show that only a very few tar- 

 nished plant bugs are to be found in the jieach blocks before the latter part of 

 June. In 1912 and again in 1913 about June 23 they suddenly increased in 

 numbers and within a week became extremely abundant. The injury to the 

 buds followed closely after the increase in the number of the insects. When 

 the tip has been punctured the leaves wilt, turn brown, and die; the bud also is 

 killed and further growth of the plant is prevented. 



While this injury to peach nursery stock, known as peach stop-back, has been 

 ascribed to other causes experiments have shown that it is produced by the 

 tarnished plant bug. The fact that the injury may be produced by nymphs, as 



