104 W. Q. Zheng et al.
trol, snail and schistosome control and herbicide
control (Bourbos et al. 1997 ; Donald et al. 2004 ;
Kaushal et al. 2002 ; Shi et al. 2009 ; Weeks et al.
2000 ; Wei et al. 2009 ; Xu 2009 ). Meanwhile, it
has gained increased attention as a contributor to
alcohol control and treatment (Ferguson 1956 ;
Jones et al. 1988 ). The present chapter reports the
results of CC killing efficacy tests on houseflies
( M. domestica) larvae (maggot), and reveals the
relationship between maggot mortality and pH.
Material and Methods
Test Maggots
Housefly maggots, M. domestica, were nurtured
in laboratory at 25–27 °C and 60–80 % relative
humidity (RH). The maggots were reared using
mixed materials whose formula was 100 parts of
wheat bran every 5 parts of dried milk powder;
dechlorinated water was added to the mixture to
the extent of water saturation but not dripping.
Eggs laid on mixed material from female house-
flies were hatched into larvae 1 for 2–3 days and
larvae 2 for 4–5 days. Randomly mixed house-
flies larvae 1 and 2 were chosen for bioassay.
Test Chemicals
Rongbao dust is a dark gray powder made by
Ningxia Darong Industrial Group Co., Ltd., the
People’s Republic of China. Rongbao® also
known as CC is a secondary product of metal-
lurgy. N resource fertilizer product Rongbao® in
this study contains approximately 50 % CC, and
other inert fillers.
Killing Efficacy
The killing efficacy of CC was evaluated using
chemical-feed-maggot complex touch technique.
The testing period lasted up to 72 h depending
on the efficacy. The timing of the tests depended
on whether the target maggots were killed by
movement when touched. Evaluations were car-
ried out in laboratory, at 26 ± 1 °C and 60 ± 10 %
RH. Maggots (larvae 1 and 2 in combination)
together with their larval rearing medium were
prepared and placed into a 100 ml beaker. Before
10 g complex was separated and introduced into a
25 ml beaker, maggots and larval rearing medium
were mixed gently and evenly using glass rod.
0.2/0.4 g Rongbao® dust on the basis of weight
were applied to the mixed larval rearing medium
and gently mixed again. The 25 ml beaker with
larval rearing medium was covered with a gauze
fastened tightly by a rubber band. The treatment
group was set to two groups ( n = 3). A series of
concentration was prepared from each treated
groups; one group for 0.2 g Rongbao® dust with
its dosage of approximately 1 %, the other group
0.4 g with approximately 2 % dosage. Dead mag-
gots in the complex were selected, counted and
recorded everyday until 72 h of deadline that was
previously defined. As a blank control, nothing
was placed on larval rearing medium with the
same process as the test group.Data Analysis
Formulated CC (Rongbao dust) was assessed
for insecticidal activity to M. domestica maggots
at dilutions of approximately 1 % and 2 % in lar-
val rearing medium. Maggots in control were not
treated with any chemical compound. The rate
of larvicidal activity of CC was calculated as the
percentage reduction in maggots’ mortality rate.
Mortality rate (MR, %) was calculated as:(1)where S is the number of the total insects in the
treated (control) beakers and L is the number of
live insects in the treated (control) beakers.
Mortality data was corrected for control mor-
tality when mortality rate of maggots in control
beakers was less than 20 %. Adjusted mortality
rate (AMR, %) was calculated as:(2)MRSLL=−×%()/ 100 ,AMRT=−()CC/,11()− × 00 %