Agriculture Reference
In-Depth Information
Other researchers have observed that insects
sometimes feed more on leaves that have lowered
nitrogen content in order to obtain suffi cient nitro-
gen for their metabolism (Coviella and Trumble
1999
). Increased carbon to nitrogen ratios in plant
tissue resulting from increased CO
2
levels may
slow insect development and increase the length
of life stages vulnerable to attack by parasitoids
(Coviella and Trumble
1999
).
beans grown at 600 and 700 ppm CO
2
. A
signifi cant decrease in the number of the off-
spring in the fi rst and second generations (34 and
49 %), respectively, was observed compared to
ambient CO
2
. A similar experiment was con-
ducted, where
T. urticae
were raised on clover
(
Trifolium repens
) grown at different CO
2
levels
(395-748 ppm). The results showed a quite oppo-
site effect: under elevated CO
2
, spider mite repro-
duction increased signifi cantly compared to
lower CO
2
. They noted that slight temperature
differences could cause signifi cantly different
reproduction rates.
Effect of increased CO
2
effects on insect-plant
interaction has been presented in Table
7.3
.
7.4.1
Spider Mites
In one study, two-spotted spider mites
(
Tetranychus urticae
) were raised on common
Table 7.3
Effect of increased CO
2
effects on insect-plant interaction
Order
Herbivore species
Host species
Effects
Comments
Acarina
Tetranychus urticae
(red
spider mite)
Trifolium repens
(white
clover)
−
Gossypium hirsutum
(upland cotton)
−
+
Phaseolus vulgaris
(kidney
bean)
Coleopteran
Papillio japonica
(Japanese
beetle)
Glycine max
(soybean)
−
Beetles and
aphids generally
perform better to
the detriment of
the plants
Diabrotica virgifera
(Western
corn rootworm)
Glycine max
(soybean)
−
Sitona lepidus
(clover root
weevil)
Trifolium repens
(white
clover)
−
Diptera
Pegomya nigritarsis
(leaf-
mining fl y)
Rumex crispus
(invasive
dock)
−
R. obtusifolius
(invasive
dock)
−
Chromatomyla syngenesiae
(leaf-mining fl y)
Sonchus oleraceus
(invasive
sow thistle)
+
Bemisia tabaci
(sweet potato
whitefl y)
Gossypium
(cotton)
ÿ
Hemiptera
Aulocorthum solani
(glasshouse potato aphid)
Vicia faba
(broad bean)
−
Beetles and
aphids generally
perform better to
the detriment of
the plants
Sitobion avenae
(grain aphid)
Triticum aestivum
(spring
wheat)
−
Myzus persicae
(green peach
aphid)
Poa annua
(grass)
−
Brassica napus
(oilseed
rape)
+
Brevicoryne brassicae
(cabbage aphid)
Brassica napus
(oilseed
rape)
ÿ
Aphis glycines
(soybean
aphid)
Glycine max
(soybean)
−
(continued)
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