Diapause in Pentatomoidea 525
The possibility of photoperiodic termination of winter adult diapause in Podisus maculiventris also
was shown in another experiment with bugs that originated from the same Missouri population (Table
11.4). In that experiment, winter adult diapause was induced by short days (L:D 12:12) at 20°C, and adults
on days 25 to 30 after emergence were transferred into long-day conditions (L:D 16:8) at 20 or 24°C.
Under both temperatures, diapause soon terminated and females started oviposition. The higher tem-
perature (24°C) had a stronger diapause terminating effect than the lower temperature (20°C), because
preoviposition period was shorter at 24°C than at 20°C (Table 11.4). However, we cannot exclude that
the difference in duration of the preoviposition period was caused by the effect of temperature on the
postdiapause maturation rates rather than diapause termination process.
The photoperiodic sensitivity during winter diapause appears to be typical of many species overwin-
tering as adults. In particular, this phenomenon was observed in the pentatomids Halyomorpha halys
(Yanagi and Hagihara 1980), Graphosoma lineatum (Nakamura et al. 1996), and Eysarcoris lewisi (Hori
and Kimura 1993). It is interesting that diapause induction requires exposure to short-day conditions
starting from the third instar in Podisus maculiventris (see Section 11.3.1.3 and Table 11.3) and from
the fifth instar in E. lewisi (Hori and Kimura 1993), whereas photoperiodic termination of winter dia-
pause in both species requires exposure to long-day conditions only in the adult stage (Hori and Kimura
1993, Chloridis et al. 1997). Thus, the sensitive periods for induction and termination of winter adult
diapause differ in length: the processes of diapause induction require a much longer action of the cue and
likely involve more profound changes in the endocrine system than the processes leading to diapause
termination. This conclusion was later supported by the results of experiments on winter diapause termi-
nation in Scotinophara lurida (Cho et al. 2008).
11.6 Environmental Factors Controlling Postdiapause Development in Spring
Studies of various insect species from the Temperate Zone in the Northern Hemisphere have shown
that for most species, winter diapause ends before December, and the most severe part of winter is
spent in a state of postdiapause quiescence (Figure 11.1; e.g., Danilevsky 1961; Hodek 1971b, 1996;
Hodková 1982; Ushatinskaya 1990; Saulich and Volkovich 2004; Koštál 2006; Saulich and Musolin
2007b). According to a very precise definition suggested by Koštál (2006; p. 121), postdiapause quies-
cence is an exogenously imposed inhibition of development and metabolism, which follows the termina-
tion of diapause when conditions are not favorable for resumption of direct development. Postdiapause
quiescence performs both functions of diapause: survival and synchronization of development; it comple-
ments winter diapause rather than replaces it, ensuring more precise seasonal synchronization (Veerman
1985, Belozerov 2009). Among the external factors controlling the resumption of active development in
spring, the most important for pentatomoids in the temperate latitudes are day length, temperature, and
TABLE 11.4
Photoperiodic Termination of Diapause in Adult Podisus maculiventris (From N. I. Goryshin, T. A.
Volkovich, A. Kh. Saulich, and I. A. Borisenko, Manuscript deposited in the VINITI (Vsesojuzniy Institut
Nauchno-tehnicheskoy Informacii [All-Union Institute of Scientific and Technical Information]), Moscow,
No. 115-B-90, 1989, with permission)^1
Temperature,
°C
Age of Adults
at the Moment of
Transfer to L:D 16:8 Number of PairsProportion of
Individuals That
Terminated
Diapause, %Preoviposition
Period, Days after
Transfer
(Mean ± S.E.)20.0 25
27–29
23
11100
10026.1 ± 1.37
25.2 ± 2.42
24.0 25–30 26 100 17.8 ± 0.93
(^1) Diapause was induced under short-day conditions of L:D 12:12 at 20°C and then adults were transferred to the long-day
conditions of L:D 16:8 at 20 and 24°C at different ages. The culture originated from Missouri, the United States of America
(about 38°N).