| Summary: | 碩士 === 國立中興大學 === 昆蟲學系 === 82 === Resistance to cotton aphid, Aphis gossypii Glover was compared
among muskmelon (Cucumis melo L.) cultivars, Tainan 8 (TN.8),
Tainan 9 (TN.9) and Autumn favor (C.T.), to assess the
possibility of controlling cotton aphid by using aphid-
resistant cultivar and parasitoid, Aphelinus mali Haldeman.
Results revealed that TN.8 was the most susceptible cultivar,
while TN.9 and C.T. were resistant with antibiosis effect of
the development and reproduction of cotton aphid by no choice
test. In free choice test, the highest population score was
found on TN.8 for each aphid colony, and the lowes was on TN.9
at 5 days after aphid released. Results from these two tests
suggested that TN.9 was more resistant that C.T.. Both of them
could delay the population increment of cotton aphid with
antibiosis and antixenosis. The influence of preconditioning
host cultivars showed significant difference among various
aphid conlonies which tamed from three different mudkmelon
cultivars, respectively. on the longevity and body weight of
apterous adult when tested on C.T., number of progeny produced
per adult on TN.8, and survival rate of progeny on all
cultivars. Host conditioning influenced antixenosis of C.T. by
exhibiting the same level as Tn.9 when tested with
preconditioned aphid colony of TN.8. but was lower than TN.9
when tested with the other two colonies, and the odor
preference to host plant cultivars. Population growth ofsypii
in field showed the slowest on TN.9, may delay the population
increment of the cotton aphid. Aphid-resistant muskmelon
cultivars had no negative impact on A. mali. No matter the host
aphids werer from aphid-resistant or suscceptible mudkmelon
cultivars.Resistant cultivars may complement the activity of
the parasitoid in reducing cotton aphid. The compatibility
between aphid-resistant mudkmelon cultivars and parasitoid is
good, therefore, it can be incorporated in the integrated pest
management program for controllong the cotton aphid population
on muskmelon.
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