Bericht des State Entomologist von Connecticut für das Jahr ... . ge Höhe des Schadens, den nur zwei Überlebende an 40 Anlagen (9,38 Prozent) angerichtet haben, verdient einen Kommentar. Dazu gehörte auch der Schaden, den die gesamte intestierende Population bis zur ersten (8. August) Behandlung angerichtet hat, sowie die neu geschlüpften oder überlebenden Larven zwischen 8. Und 18. August. 270 Connecticut Experiment Station Bulletin 472 Tabelle 29. Larve and Damage, Second-Generation Bean Beetle Tests, 1942 Anzahl der Larve Survivingon 40 Pflanzen Prozent Schaden am Laub 2 4 5 8 14 21 28 35 90 96 117 138 227 228 228 353 370 757 9.3813.7520.013.7518.7520.63

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Report of the State Entomologist of Connecticut for the year ... . ge amount of damage done by only two survivors on 40 plants(9.38 per cent) deserves comment. This included the damage done bythe entire infesting population up to the first (August 8) treatment, andthe newly hatched or surviving larvae between August 8 and 18. 270 Connecticut Experiment Station Bulletin 472 Table 29. Larvae and Damage, Second-Generation Bean Beetle Tests, 1942 Number of larvae survivingon 40 plants Per cent damage to foliage 2 4 5 8 14 21 28 35 90 96 117 138 227 228 353 370 757 9.3813.7513.7520.013.7518.7520.6320.6325.6323.7531.8828.7528.7538.7538.7536.2567.5 In a first-generation (1942) test of dosages of pyrethrum and derrison bean beetles, applications were made May 28, June 16 and June 26.Surviving larvae were counted June 29 and 30. The crop was harvestedJuly 1 to 3, and the amount of damage to bean pods recorded. The podswere sorted immediately after picking, and all pods with any feeding marksweighed separately. Table 30 and Figure 9 give the results summarized. 10 50 100 number of larvae on 40 plants-log scale 500 1000 Figure 9. Relation between number of larvae surviving treatment anddamage to bean pods, first-generation Mexican bean beetle, 1942. for treatments. The trend here is exactly the same as in the case ofdamage to foliage. Large increases in numbers of surviving larvae pro-duced only a small amount of additional damage to pods. Connecticut State Entomologist 271 Table 30. Larvae and Pod Damage, First-Generation Bean Beetle Tests, 1942 Number of larvae surviving Per cent pods injured on 40 plants (by weight) 12 3.9 20 3.1 34 8.1 35 9.438 8.171 9.174 9.1 216 9.5 254 11.8 321 10.6 544 24.6 1285 29.1 Discussion In both of these cases the curves are very flat, indicating a comparativelysmall increase in amount of damage as the number of insects is increased.The effect of increasing- populations appears to be logarithmic rather thanarithmetic. The percentage of damage ca

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