Furthermore, a change in functional response from type II to III was observed
depending on wheat cultivar in T. grandis (Fathipour et al. 2000).
Host Access Among external factors, host availability and quality are among the
most important of them. There are many reports of host escape early season due to
lack of synchrony between host eggs and egg parasitoids (Kaitazov 1968; Popov and
Paulian 1971; Safavi 1973; Kartavtsev et al. 1975; Şimşek 1986; Şimşek and
Yaşarakinci 1990; Asgari 1995; Iranipour 1996; Radjabi 2000). Egg parasitoids
come sooner and encounter to lack of the host. This event causes a negative effect on
parasitoid. Such an effect was investigated by Bazavar (2013) and Bazavar et al.
(2015) on O. fecundus and T. grandis. Five treatments of the experiment were
(1) unlimited access to host after one-week deprivation (2) access every other day,
(3) access every third days (4) access once a week, and (5) control (unlimited
access). Interrupted access had worse effect while effects were enhanced by access
intervals. A partial compensation occurred in access dates. The O. fecundus had a
slower and longer rhythm of oviposition. Oviposition rate was slow at the first and
second day, increased at the third day of oviposition, remained unchanged between
third and eighth days, and continued by a lower rate untill 23rd day. In T. grandis
oviposition rate was highest on the first day, continued by a high rate for a few days,
and then declined to zero at 19th day. Overall fecundity also was higher. Cumulatively 75 and 95% of oviposition occurred at first and second weeks of oviposition
respectively in T. grandis and 44 and 84% in O. fecundus. Compensation in
T. grandis was more considerable but did not extend to older ages. In O. fecundus
however, it was slower and extend to older ages. Final reproductive output in first
treatment (one-week deprivation followed by full access) was 78 and 92% of control
in O. fecundus and T. grandis respectively. It was 2/3 and 90% of control in every
other day treatment. In two other treatments, it was 54 and 38% of control in
O. fecundus, 68, and 47% in T. grandis.
Host Quality Many factors contributed to host quality. Host species and therefor
biochemistry of egg (factors like total protein and contents of aminoacids and other
compounds), the size of host egg, the degree of host embryogenesis, previous
parasitism, duration of cold storage etc. are among the most important of them.
Host Species Earlier in this chapter, I mentioned species examined as factitious
hosts. Among them, Graphosoma lineatum has a unique position. Different works,
however, show advantages of target pest E. integriceps to factitious hosts. For
example, Asgari (2004a) showed that T. semistriatus prefer E. integriceps eggs to
G. lineatum. Handling time on the latter was three times as much as the former.
Maximum daily attack rate was 63.5 and 20.3 on the two hosts respectively (Asgari
et al. 2001). The wasps emerged from E. integriceps eggs showed higher parasitism
and population growth rate (Asgari. 2004b). Furthermore, temperature-dependent
developmental rate of T. grandis has a steeper line slope when developed on
G. lineatum, G. semipunctatum, and E. integriceps respectively. Such a pattern led
to higher estimates of thermal threshold and smaller thermal constant in abovementioned hosts respectively. Those lines intersect around 26.5
C that may be
318
S. Iranipour
depending on wheat cultivar in T. grandis (Fathipour et al. 2000).
Host Access Among external factors, host availability and quality are among the
most important of them. There are many reports of host escape early season due to
lack of synchrony between host eggs and egg parasitoids (Kaitazov 1968; Popov and
Paulian 1971; Safavi 1973; Kartavtsev et al. 1975; Şimşek 1986; Şimşek and
Yaşarakinci 1990; Asgari 1995; Iranipour 1996; Radjabi 2000). Egg parasitoids
come sooner and encounter to lack of the host. This event causes a negative effect on
parasitoid. Such an effect was investigated by Bazavar (2013) and Bazavar et al.
(2015) on O. fecundus and T. grandis. Five treatments of the experiment were
(1) unlimited access to host after one-week deprivation (2) access every other day,
(3) access every third days (4) access once a week, and (5) control (unlimited
access). Interrupted access had worse effect while effects were enhanced by access
intervals. A partial compensation occurred in access dates. The O. fecundus had a
slower and longer rhythm of oviposition. Oviposition rate was slow at the first and
second day, increased at the third day of oviposition, remained unchanged between
third and eighth days, and continued by a lower rate untill 23rd day. In T. grandis
oviposition rate was highest on the first day, continued by a high rate for a few days,
and then declined to zero at 19th day. Overall fecundity also was higher. Cumulatively 75 and 95% of oviposition occurred at first and second weeks of oviposition
respectively in T. grandis and 44 and 84% in O. fecundus. Compensation in
T. grandis was more considerable but did not extend to older ages. In O. fecundus
however, it was slower and extend to older ages. Final reproductive output in first
treatment (one-week deprivation followed by full access) was 78 and 92% of control
in O. fecundus and T. grandis respectively. It was 2/3 and 90% of control in every
other day treatment. In two other treatments, it was 54 and 38% of control in
O. fecundus, 68, and 47% in T. grandis.
Host Quality Many factors contributed to host quality. Host species and therefor
biochemistry of egg (factors like total protein and contents of aminoacids and other
compounds), the size of host egg, the degree of host embryogenesis, previous
parasitism, duration of cold storage etc. are among the most important of them.
Host Species Earlier in this chapter, I mentioned species examined as factitious
hosts. Among them, Graphosoma lineatum has a unique position. Different works,
however, show advantages of target pest E. integriceps to factitious hosts. For
example, Asgari (2004a) showed that T. semistriatus prefer E. integriceps eggs to
G. lineatum. Handling time on the latter was three times as much as the former.
Maximum daily attack rate was 63.5 and 20.3 on the two hosts respectively (Asgari
et al. 2001). The wasps emerged from E. integriceps eggs showed higher parasitism
and population growth rate (Asgari. 2004b). Furthermore, temperature-dependent
developmental rate of T. grandis has a steeper line slope when developed on
G. lineatum, G. semipunctatum, and E. integriceps respectively. Such a pattern led
to higher estimates of thermal threshold and smaller thermal constant in abovementioned hosts respectively. Those lines intersect around 26.5
C that may be
318
S. Iranipour