69 



and as far south as Norfolk, Va. , and the strawberry leaf -roller, Pho- 

 xopteris comptana, was extremely abundant here, in Maryland, and else- 

 where. Three of the species previously mentioned, however — the 

 rhubarb curculio, zebra caterpillar, and plum moth — were not con- 

 spicuous by their numbers. 



The raspberry sawfly, Monophadnus ritbi, was more abundant than 

 in the previous year. 



The asparagus beetles, Crioceris asparagi and C. 1*2 -punctata, were 

 reported by Professor Johnson to have occasioned some injury in 

 Maryland (Bui. 26, p. 81), but the hot spell of July and August prac- 

 tically put a stop to injury, as neither beetles nor larvae of either 

 species were to be found in late August and early September, when the 

 plants in several localities were examined. 



ON SPECIES COMMON TO NORTH AND SOUTH. 



It may be well to state briefly that of the seven species previously 

 noticed (loc. cit. , pp. 57, 58) as having been particularly destructive 

 about Washington in 1899, and which do not fall into either category 

 of north or south as to origin, all were destructive during 1900, 

 although in some instances in restricted localities. 



The bean leaf -beetle, Cerotoma trifurcata, did more harm in the East 

 than was ever before known. The same is true of the spinach flea- 

 beetle, Disonycha xanthomelmna. 



One of the most interesting of injurious occurrences of the year 

 was that of the variegated cutworm Peridroma saucia, which was 

 quite destructive over a wide extent of country, including the Pacific 

 coast, where it was particularly troublesome in the State of Washing- 

 ton. The infested territory comprised portions of Texas, Missouri, 

 Kansas, Maiyland, West Virginia, Illinois, Washington, Oregon, and 

 northern California, and the crops infested included nearly everything 

 that grows in gardens, as well as the foliage and fruit of various 

 orchard trees. According to testimony of some of our correspondents, 

 this insect assumed the habit of traveling in armies, but was not 

 noticed on the march in the daytime. 



ON NATURAL ENEMIES AND THEIR INFLUENCE UPON INSECT REPRO- 

 DUCTION. 



The question of the effects of the abundance of natural enemies 

 upon injurious insects is closely related to the effects of weather upon 

 them, but the subject is much involved, and we know so little about it 

 that it is difficult to generalize with much certainty. This much is 

 certain, however, that conditions which would affect injuriously a 

 parasite may not necessarily affect a host; predaceous insects are not 

 necessarily affected by conditions which would be injurious to either 



