fourth instar larvae could be more profitable. The authors used Holling’s disc
equation and Roger’s random predator equation for estimating searching efficiency
and handling time for type II and III functional responses of C. montrouzieri,
respectively. The selection of each these two models for the data analysis does not
depend on the type of F.R. exhibited by the predator but the random predator
equation should have been used whenever there is prey depletion (Juliano 2001).
In a detailed study, the functional response of C. montrouzieri (third
. instar larva,
female and male) to citrus mealybug (second and third instar nymphs) at seven
different temperatures ranged from 15 to 40
C with 5 degrees intervals was
investigated (Mohasesian et al. 2015). They also showed type II response for all
predator stages except the third instar larvae at 40
C exhibited type III. Moreover,
there is an increase in searching efficiency (from 0.004 Æ 0.015 to
0.008 Æ 0.031 h
À1 for females) and decrease in handling time (from
0.279 Æ 2.314 to 0.216 Æ 1.821 h for females) of C. montrouzieri associated with
increasing temperature. This issue implies the greater potential of this predator at
higher temperatures, especially against mealybugs (Mohasesian et al. 2015).
Samih and Mokhtari (2014) worked on functional and numerical responses and
the predation rate of O. conglobata contaminata recommended use of this lady
beetle against green peach aphid in orchards.
As a case study, native lady beetle Nephus arcuatus Kapur functional response to
mealybug Nipaecoccus viridis (Newstead) matched Holling’s type III response
(Zarghami et al. 2014a, 2015). This result suggests this thermophilic species, mainly
found in South and Southwestern of Iran could regulate the citrus mealybug populations. High consumption rate, long oviposition period, density-dependent
functional response, direct numerical response, high reproductive potential and
ability to survive under hot temperatures all contribute to its potential to reduce
the mealybug population.
It must be remembered that there were some other functional response studies
with different lady beetle species that did not contain specific values for searching
efficiency or handling time, so we could not consider them here (Bazyar et al. 2012).
Most of the functional response studies with different lady beetle species have
been carried on to crop pests. As an exception, Rounagh and Samih (2015) reported
the type of functional response of third
. and fourth
. instars larvae and females of
O. conglobata contaminata (Menetries) to pomegranate green aphids, A. punicae at
two different temperatures. They recorded type II response for all tested stages
except fourth instar larvae, which showed type III at 25
C (Rounagh and Samih
2015). They showed the effect of increasing temperatures on searching efficiency
and handling time. As in many other studies, attack constant and handling time
demonstrate that release of fourth instar larvae of O. conglobata contaminata at
27.5
C would be the most useful approach against pomegranate aphid. However,
referring to rearing storing and releasing difficulties of a large number of fourth
. instar larvae, the females seem to be the most appropriate releasing stage.
A common deficiency of some of the above F.R. studies is the low numbers of
used replicates. In some experiments, just five or six replicates have been used while
obtaining precise estimates of search rate and handling time needs at least
70
H. Madadi
equation and Roger’s random predator equation for estimating searching efficiency
and handling time for type II and III functional responses of C. montrouzieri,
respectively. The selection of each these two models for the data analysis does not
depend on the type of F.R. exhibited by the predator but the random predator
equation should have been used whenever there is prey depletion (Juliano 2001).
In a detailed study, the functional response of C. montrouzieri (third
. instar larva,
female and male) to citrus mealybug (second and third instar nymphs) at seven
different temperatures ranged from 15 to 40
C with 5 degrees intervals was
investigated (Mohasesian et al. 2015). They also showed type II response for all
predator stages except the third instar larvae at 40
C exhibited type III. Moreover,
there is an increase in searching efficiency (from 0.004 Æ 0.015 to
0.008 Æ 0.031 h
À1 for females) and decrease in handling time (from
0.279 Æ 2.314 to 0.216 Æ 1.821 h for females) of C. montrouzieri associated with
increasing temperature. This issue implies the greater potential of this predator at
higher temperatures, especially against mealybugs (Mohasesian et al. 2015).
Samih and Mokhtari (2014) worked on functional and numerical responses and
the predation rate of O. conglobata contaminata recommended use of this lady
beetle against green peach aphid in orchards.
As a case study, native lady beetle Nephus arcuatus Kapur functional response to
mealybug Nipaecoccus viridis (Newstead) matched Holling’s type III response
(Zarghami et al. 2014a, 2015). This result suggests this thermophilic species, mainly
found in South and Southwestern of Iran could regulate the citrus mealybug populations. High consumption rate, long oviposition period, density-dependent
functional response, direct numerical response, high reproductive potential and
ability to survive under hot temperatures all contribute to its potential to reduce
the mealybug population.
It must be remembered that there were some other functional response studies
with different lady beetle species that did not contain specific values for searching
efficiency or handling time, so we could not consider them here (Bazyar et al. 2012).
Most of the functional response studies with different lady beetle species have
been carried on to crop pests. As an exception, Rounagh and Samih (2015) reported
the type of functional response of third
. and fourth
. instars larvae and females of
O. conglobata contaminata (Menetries) to pomegranate green aphids, A. punicae at
two different temperatures. They recorded type II response for all tested stages
except fourth instar larvae, which showed type III at 25
C (Rounagh and Samih
2015). They showed the effect of increasing temperatures on searching efficiency
and handling time. As in many other studies, attack constant and handling time
demonstrate that release of fourth instar larvae of O. conglobata contaminata at
27.5
C would be the most useful approach against pomegranate aphid. However,
referring to rearing storing and releasing difficulties of a large number of fourth
. instar larvae, the females seem to be the most appropriate releasing stage.
A common deficiency of some of the above F.R. studies is the low numbers of
used replicates. In some experiments, just five or six replicates have been used while
obtaining precise estimates of search rate and handling time needs at least
70
H. Madadi