. Carnegie Institution of Washington publication. 76 EVOLUTION IN COLOR-PATTERN OF THE LADY-BEETLES. MEASUREMENTS. The polygon (fig. 86) shows that the confluence of spots 5 and 6 does not represent a well-marked center of variation. Fig. 87, which is intended to test the same matter for the confluence of spots 2 and 3, fails, because of the rarity of this variant, to show its true status. The decided skew- ness in both polygons will be discussed in another (a) The distance between and confluence of spots 5 and 6. (li) Males. (c) Females. ( and 0 in Epilachna bi-<-<tli* at C
. Carnegie Institution of Washington publication. 76 EVOLUTION IN COLOR-PATTERN OF THE LADY-BEETLES. MEASUREMENTS. The polygon (fig. 86) shows that the confluence of spots 5 and 6 does not represent a well-marked center of variation. Fig. 87, which is intended to test the same matter for the confluence of spots 2 and 3, fails, because of the rarity of this variant, to show its true status. The decided skew- ness in both polygons will be discussed in another (a) The distance between and confluence of spots 5 and 6. (li) Males. (c) Females. ( and 0 in Epilachna bi-<-<tli* at Cold Spring Harbor, New York. MODIFICATION. I was unable to modify the elytra by subjecting the prepupa and pupa to changes of humidity and temperature. The pronotal pattern, how- ever, is highly subject to modification by high temperatures. Fig. 85 gives the range of the wild specimens. Individuals kept in an incubator at 40° C., and even those placed in the hot attic of the station buildings during summer months, became very light in every case, as shown in fig. 88, and closely approached the Texan species E. toweri. Some of the spots, besides being smaller, have a lesser amount of pigment proportionately, so that they were in some cases brownish rather than black. Prolonged refrigeration, darkness, increase and decrease of humidity produce no appreciable effects. Experiments with the high temperature referred to, combined with high humidity, gave results similar to those with the high temperature alone. Excessive heat was, therefore, the only agent to produce modification and this was in the direction of reduced pronotal pigmentation. The pupal coloration is subject to high pigmentation after a temperature of 17° C. With the temperature at 40° C. the exuviae possess no pig- ment, except in the spines. In the former case, the pigmentation was generally associated with lines of greater frequency of Please note that these images are extracted from scanned page images
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