PHENOLOGICAL NOTES ON A NON-MIGRATING POPULATION OF PINEUS FLOCCUS (HOMOPTERA: CHERMIDAE)

Abstract

Volume 99THE CANADIAN ENTOMOLOGIST 765 other hand showed no significant difference from the laboratory strain in either series of tests, with a difierence of 12.2% (x' = 2.62, P > 0.1) and 3.7% (f = 0.19), respectively, for generations 1 and 4.These results indicate that both strains were reverting to a behavior pattern similar t o that exhibited by the laboratory strain. It is difficult to satisfactorily explain the development of the behavioral change exhibited by the experimental strains in the multi-cell systems or the selective pressures involved. It may have been that the modification in this behavior pattern was due to secondary effects of some other change that developed, but remained undetected. T h e only other difference that was found between these strains was a slightly lower rate of reproduction in parasites from strain I1 compared with strain I. T h e dynamics of the interacting population~ in the multi-cell systems, however, were different in the later phases of their existence. For this report it would be sufficient t o point out that the blowflies in system I developed an ability to move from cell to cell at a faster rate than those of system 11. This resulted in great fluctuations of the populations in system I and a corresponding greater amount of movement from cell to cell within the system (in preparation). T h e parasite strains, however, were examined for emigratory behavior and neither strain exhibited a tendency to move from cell t o cell faster than the other. T h e behavior pattern relative to the distribution of hosts attacked appears to be a hereditary trait.

Scale Insects: What the Arboriculturist Needs to Know about Them

“…7), and the twice stabbed ladybird beetle, Chilocorus stigma (Say), which feeds upon pine needle scale, beech scale, Terrapin scale, and others, seldom produce dramatic reductions in scale numbers until after substantial tree damage has occurred. However, DeBoo and Weidhaas (1976) working in Scots pine plantings in New York found that C. stigma can cause substantial reductions in pine needle scale populations. They suggest that by introducing large numbers of C.…”