1020] ECONOMIC ZOOLOGY — ENTOMOLOGY. 355 



"During 1916 apples luul a ^rrratcr lantic and a lii^'hcr mean iiiihiIkm* of seed.s 

 per api»le tliaii fniits of the following; year. Tliis coiulition was notecl with 

 both iioriiial and aphis apples. Init with normal fruits the difference in 

 variability was nt'^ll^it)h\ The avera^^e weiplit of s(>eds per apple was >:r«ater 

 witli normal fruits, and in comparison with apliis aitples durinj: the past two 

 years tlie difference has been marked. Tlie vari;r1)ility in weij,'lit of seeds was 

 also much ;,'reater with in.jur(il fruits. In normal fruits the avera^'e weifjlit 

 of seeds per apple and the ranfie in weij^ht were jrreater in 1910 than in 1917. 



" As judjied by size, plumpness, and appearance of integument, both classe.s 

 »)f fruits contained imperfect seeds. These were more abundant in ar>his- 

 injured fruits. A.s selected, normal apples weighed more than aphis apples. 

 During 191C they averaged 2.0 times the weight of aphis-injured fruits and 

 during 1917 they were o.'2 time.s heavier. The coeflicients of vari-abillty both 

 seasons were considerably greater with the injured than with the normal fruits. 

 Nothwithstandlnj^ dilVereiices in average weiglit of seeds, normal apples 

 weighed approximately the s^lme for both seasons. 



" Injuries by the aphis did not affect all structures of the apple to the same 

 degree. The greatest percentage of decrease occurred in the weight of the 

 individual fruits, with a smaller decrease in the weight of the seeds and the 

 least decrease in the number of seeds. A comparison of variability in the 

 several stl^]ctures of normal apples showed that the variation in the number 

 of seeds per apple is the most marked, followed by weight of seeds, while 

 weight of fruits is the least variable. In aphis apples, however, the varialiility 

 of each character is greatly increased over that found in normal apples, weight 

 of seeds being highest, number of seeds intermediate, and weight of fruits least 

 variable. The coeflicients of correlation between weight of seeds and uvmiber of 

 Ree<ls per apple in aphis-injured and normal fruits both seasons were positive 

 and higb, but the regression coefficients of the two .series eack season did not 

 differ to any great extent. There ai*pears to be a clo.ser relationship ]>etween 

 fruit weight and seed weight in small apples than in Uirge ones, but in none 

 of the series is the relation between fruit weight and seed weight very marked. 



" Severely malformed fruits sustained no reduction in the number of primary 

 fibi-o-vascular structures. The strands on the side of greatest distortion gen- 

 erally showed suppres.sions in development and displacements with respect to 

 distance from the vertical axis of the ai)ple and the amount of space between 

 the different elements. The ultimate branchlets did not display the dense plume- 

 like ai)pearance which is characteristic of normal, ripened fruit. Irregular de- 

 velopments in form and structural arrangetnents of fruits occur indepen(>wnt 

 of the work of the rosy ai)his. Attacks of such apples by the insect tend to 

 aggravate the distortions." 



The work of Kinpoasca iiiali on potato foliage, P. J. 1'akkott and II D. 

 Olmstead (Jour. Econ. Ent., IS (1920), No. 2, pp. 22J^-226) .—The author reports 

 ur>on 9 cage and 1 field experiment with E. iiioli at Geneva, N. Y. 



In all the experiments, feeding by the insects produced at fir.st small brownish 

 areas of 0.25 in. or more in width at the tips and occasionally on the margins 

 of the leaflets. The injury became more conspicuous as the season advanced, 

 the brownish or burned areas increasing bftth in extent and numbers. The 

 discoloration progre.ssed from the tip toward the base of the leaf, and fntm 

 the margins toward the midrib. As the tissues became desiccated the margins 

 rolh'd up over the upper surface, leaving a small narrow strip of green tissue 

 in the central area of the leaflet. In instances where such injuries were 

 severe, all the leaflets curled and completely dried up, while the petioles often 

 withered ami dried so that any slight disturbance produced defoliation. 

 2482°— 20 5 



