566 Invasive Stink Bugs and Related Species (Pentatomoidea)
and Lopatina 2007) but also include some Chelicerata (Belozerov 2007, 2012) and Crustacea (Alekseev
1990, Hairston and Cáceres 1996). The study of seasonal cycles in representatives of the Pentatomoidea
would expand the capacities of such an analysis.
In our previous communications (Saulich and Musolin 2007a,b, 2011, 2014b; Chapter 11), we pro-
posed a system of seasonal adaptations involved in the formation of various annual cycles of insects.
Among such seasonal adaptations, we considered four categories of phenomena that determine the sea-
sonal cycles of insects:
- active (i.e., nondiapause) physiological state and responses controlling active develop-
ment, mostly its rate (e.g., control of growth rate by temperature and day length, different
behavioral responses aimed at maximizing of fitness); - diapause and responses controlling the formation, development, and termination of the state
of physiological dormancy (first of all diapause), both facultative and obligate; - migrations and responses allowing the insects to actively avoid the adverse conditions by
movement; - seasonal polyphenism and responses controlling the morphological and physiological
characters (e.g., coloration; body shape, size, and proportions; and the degree of development
of wings and/or wing muscles) that often are closely associated with diapause or some other
form of seasonal dormancy (see Chapter 11 for details and examples).
Combinations of these seasonal adaptations underlie the diversity of seasonal patterns of insects,
which, in turn, can be classified into several basic types. First of all, one can distinguish between the
homodynamic and heterodynamic types of seasonal development, and the corresponding seasonal
cycles. In the former case, the insects remain in the active physiological state all year-round; in the latter
case, periods of active development alternate with periods of seasonal dormancy of varying duration and
i nt en sit y.
Homodynamic seasonal cycles are largely characteristic of species living under relatively stable
conditions: inhabitants of the tropical and subtropical zones, synanthropic and cave species, and some
soil-dwelling insects. In the Northern Hemisphere, homodynamic seasonal development often can be
observed in the southern geographic populations of those species, which are heterodynamic in the
temperate climate. For example, populations of the spined soldier bug, Podisus maculiventris (Say), in
Florida, the United States of America (30°N), develop without diapause (De Clercq and Degheele 1993),
so that adults of this species can be found there all year-round (Richman and Mead 1980). Populations
of the southern green stink bug, Nezara viridula (L.), living still closer to the equator also lack diapause:
in India (23°N; Singh 1973) and Brazil (23°S; Panizzi and Hirose 1995), oviposition of these bugs was
recorded even in winter, which is impossible in the temperate part of the species range. Homodynamic
seasonal development also is likely to be characteristic of the bagrada bug (painted bug), Bagrada hilaris
(Burmeister), and the harlequin bug, Murgantia histrionica (Hahn), in southern areas such as India
(Singh and Malik 1993, Siddiqui 2000) and the United States of America (McPherson and McPherson
2000, Taylor et al. 2015; see also Chapters 3 and 6).
However, the permanent existence of insects under more severe climatic conditions with pronounced
seasonality of climate in subtropic, temperate, and polar latitudes depends on invariable alternation
of periods of active development and seasonal dormancy. Such a heterodynamic seasonal cycle can
exist in the forms of univoltinism (i.e., a type of seasonal development with univoltine cycles), mul-
tivoltinism (i.e., a type of seasonal development with bivoltine, trivoltine or multivoltine cycles),
and semivoltinism (i.e., a type of seasonal development with cycles, that are longer than one calendar
yea r).
The main distinguishing trait of a univoltine cycle is completion of strictly only one generation during
the vegetative season whereas in the multivoltine cycle, two or more generations can be formed dur-
ing a season. An important trait of the multivoltine seasonal cycle is that the overwintered generation
gives rise to consecutive summer generation(s), and the last annual generation, in turn, forms diapause
and overwinters. The ecological control of multivoltinism has proven to be essentially similar in most