Invasive Stink Bugs and Related Species (Pentatomoidea)

Seasonal Cycles of Pentatomoidea 589

probably was sufficient for the prediapause feeding but too low for the physiological processes associated
with the change of body color (Musolin and Numata 2003b).
Thus, we are dealing here only with the initial stage of expansion of Nezara viridula into the central
part of Japan. To become completely and successfully established in this region, the population should
undergo adaptive changes in the PhPR parameters that determine the dates of induction of the winter

15

40

Air temp

erature, °C

35

30

25

20

15

10

5

-5

Ser. 1

Ser. 2

Ser. 3

Ser. 4

Ser. 5

Ser. 6

0

13

Da

y leng

th,

h

11

9

25

20

15

10

5

0

25

20

15

10

5

0

25

30

35

20

15

10

5

0

25

30

35

20

15

No. of female

s

10

5

0

L4-L5 nymphs died by late Apr

L1-L2 nymphs died by mid-Dec

JulJAugSep Oct Nov DecJan Feb Mar AprMay Jun ul AugSep

FIGURE 12.18 Seasonal development of the southern green stink bug, Nezara viridula, in six series of quasi-natural
experiments performed in Osaka (34.7°N), Japan. Arrows: dates when egg clusters were transferred to field conditions.
Histograms: number and coloration of females (nymphs and males not shown). Dotted lines: total number of mating
females; solid lines: number of ovipositing females. Light columns: green adults; shaded columns: adults with intermediate
coloration; filled columns: brown or russet adults. L1–L5 are nymphal instars. The natural conditions: curve: day length;
broken lines: daily minima and maxima of temperature. (From D. L. Musolin and H. Numata, Ecological Entomology 28:
694–703, 2003, with permission.)