The Antestia Bug Complex in Africa and Asia 473
asl, the incubation period was reported as 4 to 9 days by Hargreaves (1930); in Tanzania, at ≈900 m asl,
from 5 to 6 days in February and March and from 8 to 10 days from June to August (Kirkpatrick 1937);
and in Rwanda and Burundi, 9 to 13 days, with a significant influence of humidity (Foucart and Brion
1959). A recent study conducted with individuals of A. thunbergii collected on Kilimanjaro, Tanzania,
and maintained in climatic chambers as a colony in Kenya reported mean egg stage durations of 8.9, 5.0
and 4.0 days at constant temperatures of 20, 25, and 30°C, respectively (Ahmed et al. 2016). Kirkpatrick
(1937) reported that, when they were ready to hatch, all of the eggs in a cluster hatched in 2 or 3 hours.
He also stated that in the absence of parasitoids, egg viability was high, with ≈100% of the eggs hatching
at outside temperatures. In Kenya, egg viability of 94, 57, and 15% was reported at constant temperatures
of 20, 25, 30°C, respectively, with the colony from Kilimanjaro (Ahmed et al. 2016).
10.3.3.1.2 Nymphal Instars
Antestiopsis thunbergii has five instars. Newly hatched first instars usually stay together on the egg cho-
ria for 1–3 days (Figure 10.1E) before beginning to feed. Sometimes, they can molt to the second instar
without feeding, but, in this case, mortality is high (Kirkpatrick 1937).
Reports from Anderson (1919) and Kirkpatrick (1937) showed high variations in the durations of the
nymphal stadia, depending on elevation and time of the year, with mean durations between 5.8 and 15.1
for the first stadium, 9.4 and 33 days for the second stadium, 10.4 and 22.5 days for the third stadium,
10.5 and 22.5 days for the fourth stadium, and 13.0 and 22.3 days for the fifth stadium. Foucart and Brion
(1959) reported that both the duration of nymphal development and nymphal survival varied during the
year, even in rearing conditions with standard feeding conditions. They assumed that nymphal develop-
ment time was linked to evaporation, with high evaporation leading to shorter development time.
Table 10.1 shows results obtained by Le Pelley (1968) with a population from Kabete, Kenya, reared
in an open-air shelter and those of a recent study with a population from Kilimanjaro, Tanzania, in
incubators at constant temperatures (Ahmed et al. 2016). Clearly, as is usual for insects, development of
nymphal instars was faster at higher temperatures. The above authors agreed that there was no difference
in the duration of development between males and females.
10.3.3.1.3 Adult Stage
Morphology of Antestiopsis thunbergii adults is quite variable in size and coloration patterns in such
a way that it is not easy to give an accurate description of the species. The bugs are between 7.5 and
9.5 mm, with females usually somewhat larger than males. Irrespective of the sex, the pronotum and
scutellum have striking variable patterns with black, orange and white as colors (e.g., Figure 10.1A). The
cuticle of the wing has orange and white marks, whereas the membrane and hind-wing are dark brown
(Le Pelley 1968).
TABLE 10.1
Development Duration of the Five Nymphal Instars of Antestiopsis thunbergii Reared at Four Average
Temperatures in an Open-Air Shelter in Kenya (Le Pelley 1968)^1 and at 3 Constant Temperatures
in Incubators with Individuals from Kilimanjaro, Tanzania (Ahmed et al. 2016)^2
Development Stage Duration (in Days)
Stage 1 Stage 2 Stage 3 Stage 4 Stage 5 Egg-Adult
Average temp. (°C)^1
16-17 12-15 28-35 15-26 21-30 25-40 101-146
17-18 10-13 18-28 15-19 14-24 17-32 74-116
18-19 7-12 17-29 11-18 9-24 14-30 58-113
19-20 7-9 17-26 10-19 6-23 14-31 54-108
Constant temp. (°C)^2
20 8.5 25.4 15.6 13.6 19.4 89.6
25 5.0 11.3 10.7 12.7 18.9 63.1
30 3.3 9.4 9.6 10.1 18.9 55.8