Seasonal Cycles of Pentatomoidea 571
of low winter temperature (Javahery 1994). Adults of the summer generation emerge in June–July but
reproduce only late in autumn. Unfortunately, the cited authors did not study the physiological state of
the females in summer, so that the existence of summer adult diapause was not confirmed. At the same
time, phenological observations clearly indicate the presence of obligate winter diapause at the egg stage
and the development of only one generation per season.
12.2.1.2 The Univoltine Seasonal Cycle Based on Obligate Nymphal Diapause
Obligate nymphal diapause is comparatively rare in the Pentatomoidea; however, it has been recorded in
a few species (see Chapter 11 and Tables 11.1 and 11.2).
A plataspid Coptosoma scutellatum (Geoffroy) occupies meadows, grasslands, and other open, well
insulated and, thus, warm habitats. Its host plants are perennial legumes (Fabaceae): alfalfa, clover, broom,
and many others (Putshkov 1961). The species always produces only one generation per year. Nymphs of
the third and fourth instars overwinter in aggregations (Davidová-Vilimová and Štys 1982; Figure 12.4).
For the population from Central Bohemia (The Czech Republic), it was reported that in some cases,
younger nymphs (first and second instars) also can overwinter in temperature- (but not day-length-) con-
trolled oligopause (i.e., a less intensive suppression of development than diapause; Davidová-Vilimová
and Štys 1982). Later, however, laboratory studies of this species in the forest-steppe zone in Russia
(50°N) showed that, normally, only nymphs of the third and fourth instars can overwinter in a state of
true diapause (not quiescence or oligopause; Saulich and Musolin 1996, 2014a; Musolin 1997). Effect of
environmental factors such as two temperatures (24.5 and 28.0°C) and different constant and increasing
5 n
5 im
4
3
2
1
E5 n
5 im
4
3
2
1
EIII III IV VVIVII VIII IX XXIXII
MonthsCoptosoma scutellatumCoptosoma mucronatumDevelopmental stagesFIGURE 12.4 Seasonal presence of different life stages and instars of two plataspids – Coptosoma scutellatum (in
Bohemia, The Czech Republic) and C. mucronatum (Southern Slovakia). E – eggs; 1–5 – nymphal instars; 5 im – fifth
instar nymphs parasitized by the braconid Aridelus egregius (Schmiedeknecht); 5 n – normal (i.e., nonparasitized) fifth
instar nymphs. (From J. Davidová-Vilímová and P. Štys, Acta Universitatis Carolinae Biologica 11: 463–484, 1982, with
permission.)