a level at the peak of the population. The drought weather conditions may
have had a significant impact on pupal eclosion, since the population declined
from the initial count throughout the remainder of the growing season. There
is no doubt that the drought had an effect on the budworm population, since
the population peaked on the pretreatment count and declined for the remainder
of the test period. The unusual decline is the first time in 33 years that it
has started with the pretreatment count. Usually the decline is precipitated
by topping of the plants at or near the buttoning stage of plant development.
The budworm decline cannot be attributed to cold weather as the winter was
rather mild with no severe prolonged freezes. Populations of the tobacco
hornworm were considerably smaller than in 1987. The first infestation in the
field was not noted until May 25, which was almost three weeks later than in
1987. The peak in hornworm damaged untreated plants occurred on June 8, and
never exceeded that peak for the remainder of the growing season. The peak in
damaged hornworm plants in 1988 was 42.4% smaller than the peak in 1987. The
predaceous wasp that was observed in large numbers in 1986 was absent from the
test plots in 1988. No doubt that the drought weather adversely influenced
the hornworm population much as it did the budworm population. However,
mature 5th instar hornworm larvae were rare on infested plants, which was
probably an association of the small population that was present. Rainfall
during the growing season was 9.67 inches less than that for 1987. The rain-
fall was the smallest amount recorded since 1981, when 9.29 inches occurred.
Yield of untreated tobacco in 1987 was 2,255 pounds per acre compared to 2,871
in 1988, which indicated that the small populations of budworms and hornworms
were responsible for the increase in yield. This marks the 20th year in suc-
cession that no control data have been obtained on the cabbage looper because
populations on the crop have been nonexistent.

 Green peach aphids began building populations on field plants on April 25
(pretreatment count), which were smaller than in 1987. Populations increased
rapidly on untreated plants until June 22, when populations began declining.
The populations at the peak level on June 8 were 1.3 times larger than the
peak level on June 3, 1987. The favorable weather conditions in 1988 enhanced
aphid reproduction, which resulted in the large populations. Populations of
aphids on the last count on July 6 were located on new sucker growth, but did
not reach as large a level in those locations as in 1987. (See Table 2.) On
June 8, when populations were the largest on the untreated tobacco checks, all
treatments gave significant (P = 0.05) control, but the control obtained with
all three dosages of F-7869 would not be commercially acceptable. Any treat-
ment on June 8 that had counts in excess of 1,000 would not be acceptable to
the grower. The data on June 8 indicated that both dosages of Lannate were on
the border of being unacceptable. Although there was no statistical differ-
ence between Capture, Lannate, and Orthene, all dosages of Capture and Orthene
were numerically superior to Lannate for aphid control. The yield and dollar
return data in Table 6 indicated that the aphid may have contributed to a re-
duction in both parameters, especially in F-7869 treated tobacco.

 Budworm populations were smaller initially than in 1987, and never
attained as large a level at the peak on April 25, 1988. The population
peaked about a month earlier than in 1987, and began declining prior to
topping, which was an unusual phenomenon. A similar pattern of population
decline occurred in 1987. The population decline in past observations (prior
to 1937) has been consistently associated with topping, which was related to
removal of the inflorescence and seed heads the preferred feeding sites of
the budworm. Weather conditions were not considered a factor in the 1987