Losses caused by rodents to economic field crops and fruit trees

Full text

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Al-Azhar University
Faculty of Agriculture
Department of Agricultural Zoology and Nematology
Review article
On
Losses caused by rodents to economic
field crops and fruit trees.
BY
Dr. Ahmed Aatef Reyadh Al-Gendy
Lecturer of Rodents in Agric., Zoology and Nematology Department
Faculty of Agriculture
Al-Azhar University
2010
Introduced to the permanent scientific committee
for promoting Professors and associate Professors
in Agricultural Zoology and Nematology
Al-Azhar University.

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Contents
ITEM
Page
Ӏ- Introduction.
1
ӀӀ-losses caused by rodents to economic field crops.
3
A- Pre-harvest losses.
3
A-a- Cereal crops
3
A-a-1- Rice crop.
3
A-a-2- Wheat crop.
8
A-a-3- Maize crop.
11
A-b-Sugar crops
14
A-b-1- Sugar cane crop.
14
A-b-2- Sugar beet crop.
15
B - Post-harvest losses.
17
ӀӀӀ-losses caused by rodents to fruit trees.
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ӀV-Discussion.
28
V-Recommendation.
29
VӀ-References
30

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ISTE OF TABLES
No. of table
Page
Table (1): Major agricultural rodent pest problems for food
crops in selected regions, their importance as food
competitors with people, and methods of control
being applied in Africa.
25
Table (2): Major agricultural rodent pest problems for food
crops in selected regions, their importance as food
competitors with people, and methods of control
being applied in Asia and Australia.
26
Table (3): Major agricultural rodent pest problems for food
crops in selected regions, their importance as food
competitors with people, and methods of control
being applied in Europe, South and North America.
27

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LISTE OF FIGURES
No. of figure
Page
Fig.(1):Wildlife biologist Rachel Labador is surrounded by rat-
damaged fields (see the bare, brownish patch) in
Banaue, Philippines.
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Fig.(2) : Damage caused by rats to wheat crop.
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Fig.(3) : Damage caused by rodent to maize crops.
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Fig.(4) : Damage caused by rodent to sugar cane crop.
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Fig.(5) : Damage caused by rodent to sugar beet crop.
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Fig.(6) : Stored rice contaminated with rodent feces.
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Fig.(7) : Roof rat damage to oranges.
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Fig.(8): Damage due to mice (properly referred to as "voles" but growers
simply call them "mice"), is most serious when their normal food
supply is limited. Mouse injury to fruit trees mostly consists of girdling
of trunk and roots and sometimes root pruning ( A and B).
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Ӏ- Introduction
Rodents are a key mammalian group, which are highly successful in
many environments throughout the world. They constitute more than
42% of the known mammalian species. In many instances rodents provide
major benefits to the environment as bio-engineers. However, of major
importance is the 5-10% of rodent species that cause significant losses to
agricultural crops in many regions of the world (Rao and Bai, 2004).
Types of rodent pests in Egypt and World
Approximately 4000 rodent species are divided on the basis of their
anatomy into three well-defined groups, or suborders, and more than 30
families.
1-The Sciuromorpha, or squirrel like rodents, include the various species
of squirrel, chipmunk, prairie dog, pocket gopher and pocket mouse.
2-The Hystricomorpha, or porcupine like rodents, include the porcupine, ,
nutria (coypu) and agouti.
3-The Myomorpha, or mouse like rodents, it is the largest rodent group. It
includes a great variety of mouse and rat species, as well as species of vole,
muskrat, gerbil and jerboa. (Hoogostraal,1963), (Osborn and Helmy, 1980),
(Meehan, 1984), (Wilson and Reeder, 1993) and (Chopra et al., 1996).

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Whilst a majority of rats and mice thrive in the natural environments,
some species have adapted to the human settlements, causing nuisance
to the human populations.
The major harms caused by these commensally rodents include:
1-Economic losses and illnesses caused by their consumption and
contamination of economic field crops (pre- and post-harvest) and fruit
trees.
2-Economic and property losses caused by their burrowing and gnawing
habits.
3-Fire hazards resulted from their gnawing on electric wires and cables.
4-Potential health risks to humans as they are hosts or vectors of various
kinds of communicable diseases.
Most of the economic losses caused by rodents occur in cereal crops
(Kami, 1966), (Brooks and Barnes, 1972) and (Bertolino, 2005) although
significant damage occurs annually in both sugar cane and macadamia
orchards, (Ramsey and Wilson, 2000).
This review aiming to describe:
1-losses caused by rodents to economic field crops.
a- Pre-harvest losses.
b - Post-harvest losses: extent of the problem.
2- Losses caused by rodents to economic fruit trees.

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ӀӀ-Losses caused by rodents to economic field crops.
A- Pre-harvest losses
A-a- Cereal crops
The severity varies with season, location and ecosystem. Among the field
crops, rice is the most vulnerable crop to rodents. Rodents do not spare any
variety and they attack all stages of the crop during all seasons (Sridhara, 1992).
A- a-1- Rice crop
The assessment of damage caused by rodent to rice was carried- out as
the following technique. Three fields were selected, each was a feddan area.
15 samples were selected diagonally and were determined by using wooden
frame (100 x 100 cm). In each sample, the numbers of damaged and
undamaged tillers (The Cut Tiller Count method) inside the frame were
counted, and the percentage of damage was calculated according to
Hamelink (1981) and Poche et al., (1982) as follows:
Number of damaged tillers
% Damage = x 100
Total tillers counted
In India, Prakash et al., (1986) found that the damage to the paddy
tillers was significantly (P<0.01) more in the centre of the paddy fields than
at the rice periphery and middle zone. The damage to the paddy tillers were
(8.62% to 9.5%), (8.43% to 9%), (5.75% to 6.23%) and (5.75% to 6.5%) in
Nadia, Hooghly, North 24-Parganas and Burdwan districts respectively, while
was 13.86% at the State of Punjab Chopra and Parshad (1986).
Rice damage at different stages, by rodents has been estimated to be
10%. The severity varies with season, location and ecosystem. Among the
field crops, rice is the most vulnerable crop to rodents. Rodents do not spare
any variety and they attack all stages of the crop during all seasons. In
addition to tiller cutting, they also hoard ripened panicles inside their

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burrows. They have tremendous hoarding capacity especially in Bandicota
bengalensis and Mus meltada. Hoarding by Bandicota bengalensis was
observed in the farm at the time of harvest. Maximum damage to nurseries
takes place when the seeds are just germinated. At this stage, the nurseries
are drained out and the rodents run freely inside the bed spoiling all
germinated seed. Later, they also cut the seedlings 1-2 inches above the
water level. Sometimes the rodents pull out the transplanted seedlings and
create gaps in the main field. Generally, their activity is confined to inside
field leaving 2-4 meters on all sides of the field. In the initial stage, damage
appears in patches and after some time, all these small patches become into
one big patch. Damage increases with the onset of panicle initiation and
continues up to panicle emergence (Sridhara, 1992).
Analysis of the information available on the damage and economic losses
caused by rodents in rice, wheat, sugarcane, maize, pearl millet, sorghum, oil
seed, legume and horticulture and forestry and rural and urban dwellings
and storage facilities clearly shows that chronic damage ranging from 2% to
15% persists throughout the country and severe damage, sometimes even
up to 100% loss of the field crop, is not rare (Parshad, 1999).
Santra et al., (2001) estimated the damage caused by Indian house rat
Rattus rattus (Linnaeus); brown or sewer rat, Rattus norvegicus
(Berkenhout), house mouse Mus musculus Linnaeus, and Large bandicoot rat
Bandicota indica Bechstein, in three districts of West Bengal. House rat,
Rattus rattus (Linnaeus) was the most dominant rodents which caused
excessive damage on field and stored crops at West Bengal. The damages
made by these rodents were approximately 5-6% paddy in the field and 7%
in the stores; 6-7% wheat in the field) and 1-8% other crops.

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In Madagascar, the most important rodent pest is the roof rat (Rattus
rattus). The impact of the rat on rice crops was studied in the region of Lake
Alaotra, the principal rice-producing region of Madagascar. Evaluation of
rodent damage was conducted in 591 parcels just before harvesting. The
average damage value was low (on average less than 1%) and the average
losses per hectare were also low at less than 100 kg paddy rice/ha.
Differences were significant, depending on the locality and the presence of
good refuge habitat for rats around the rice field. The rice variety and
agronomic practices did not influence the damage levels (Salvioni, 1991).
In Indonesia, rodents are the most important pre-harvest pests in
economic terms, causing on average at least 15% annual losses of rice
(Geddes, 1992).
Rodent damage to rice can be measured at several stages of crop growth.
In West Java, monocultures of lowland irrigated rice, cumulative damage to
rice during the dry season was 54% at the primordial stage and 32% at the
booting stage, but only 16% at the ripening stage. In deep water rice
systems, B.bengalensis and B.indica can cause significant damage to pre-
flood rice as well as non-rice crops. More damage occurs at the rice stem
elongation stage through stem cutting and biting opening the leaf sheath
(Singleton and Petch, 1994).
Rice yield can be estimated by farmers directly or by quadrate samples,
the former being on average 20% lower than the actual yield. Integrated
rodent management increased rice yields more when rats were common, in
both dry and wet season crops. For every 1% increase in tiller damage by
rats, there was a decrease of 58 kg/ha in rice yield. The benefit-to-cost ratio
for all seasons and years averaged 25:1 but varied considerably from year to
year between a low of −2:1 to a high of 63:1 (Singleton et al., 2004).

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Surveys in Bangladesh have found that rats attack 37% of fields at the
beginning of the flood period, rising to 52% at harvest when rats cut the
panicles for storage in their burrows. Yield loss assessments have been
shown to vary widely temporally and spatially. There is limited economic
assessment of the effect of rats on rain-fed deepwater rice. However, studies
over two years in Bangladesh which assessed actual yield loss caused by rats
during the entire growth period showed losses ranging from 32% to 67%.
These studies also showed that damage during elongation was more severe
than that suffered during ripening (Aplin et al., 2004).
In common with most of Asia, Bangladesh farmers routinely plant 2 rows
of rice for the rats for every 8 rows sown, pre-harvest losses ranging from 5-
17% (Belmain and Shafali, 2008) and (Meerburg et al., 2008) .
A survey of 350 farmers was conducted in the lowland rain fed
agricultural system of central Myanmar (Burma) to examine the importance
of rodents, farmers' perception of the causes of yield loss, and their beliefs
as to why they undertake rodent management. Farmers grew monsoon rice,
summer rice and mungbeans with the major constraints upon production
identified as pests (29.4% of respondents), followed by insufficient water
(19.4%). The main pests were insects (48.6%), followed by rats (40.9%);
however, farmers thought that rats caused most damage to their crops
(47.7% of respondents; insects 30.3%), and were the most important pest to
control. Farmers estimated that rodents caused 13% yield loss. Rodents were
clearly identified as a significant problem by farmers (Brown etal., 2008).

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A- a- 2- Wheat crop
Alfonso (1968) mentioned that, as wheat heads mature rats feed on the
base of the young pencil shoot and completely bite off the stem and feed on
the grain, Figures (1 and 2).
Fig.(1):Wildlife biologist Rachel Labador is surrounded by rat-damaged
wheat fields (see the bare, brownish patch) in Banaue,
Philippines.
.
Fig. (2): Damage caused by rats to wheat crop.
The assessment of damage in wheat crop follows the same steps
previously mentioned with rice crop.

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In Egypt, Abdel-Gawad et al., (1982) estimated the damage caused by
A. niloticus (Des.) in wheat field. They found that the maximum attack by this
rat was more predominant during the milky and paste stage and the damage
decreased gradually towards the center of the field.
Abdel-Karim (1991) studied the damage caused by Arvicanthis niloticus
(Des.) in wheat fields at Sharkia governorate. The rat attacks wheat plants all
over the growing season. The signs of infestation started to appear during
the second week of December but wheat plants subjected to relatively high
damage during milky and pasty (dough) stages in March and April.
In Minia governorate Asran (1991) and in Fayoum governorate
Asran et al., (1991) found that the damage by rodent species in wheat crop
started at the early growth stage and increased during the milky and dough
growth stages, this was supported by Keshta (1996) in Qena, Beni Suef and
Kalubia governorates and Abdel-Hamid (1997) in Fayoum governorate and
El-Nashar (1998) in Minia and Sohag governorates.
Losses to wheat crop due to large jird, Meriones shawi isis (Thomas) were
about 2.46 Ardab/Fed., by and decreased to 1.03 Ardab/Fed., during 2001
and 2002 agriculture seasons, respectively, using live trap method. However,
there was no damage with the use of crashing burrows method in Behria
governorate (Metwally et al., 2009).
In Kano, northern Nigeria, The damage and yield loss caused by two
rodent species, Arvicanthis niloticus and Mastomys (Praomys) natalensis, in
cereal crops in fields from August, 1990 to April, 1992 were investigated. In
premature crops, damage increased from tiller stages to the dough stages.
Statistically significant differences in the percentages of damage (yield loss)
in mature rice (4.8% in 1990 and 12.6% in 1991) and in wheat (30.0% in 1991
and 21.7% in 1992) were found. Severe yield losses in wheat, compared to

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low and moderate levels in rice (grown for the most part during the rains),
were probably a result of greater consumption of the wheat, grown entirely
by irrigation during the dry season when other rodent food sources were less
abundant. The results showed significant effects of developmental stage of
the crop, year of cultivation, and their interactions on the magnitude of crop
damage (Rabiu and Rose, 2004).
In Bangladesh, Poche et al., (1982) studied wheat yield reduction by the
lesser bandicoot rat, B. Bengalensis. The damage caused by this rat on
mature wheat was 12.1% or 77000 tons of grain destroyed before harvest
and 17% of the damaged tillers were removed; whereas, 83% of them were
cut near the ground level.
In southern Australia, Plagues of house mice, Mus domesticus can cause
severe economic damage to grain crops when their populations peak at
sowing of winter-growing crops in autumn. Mice damage crops by locating
and digging out newly sowed seeds. If damage is high, farmers have to re-
sow their crop. A trial was conducted to examine the effect of increasing
sowing depth of short and long coleoptiles wheat. Crops were sown at 30, 50
and 70 mm and the germination rate and number of mouse diggings was
compared in an open field and a mouse-proof enclosure (fenced site). The
effective loss at emergence on the open field compared to the fenced site
was 10–18% for wheat, (Brown et al., 2003) and (Brown, 2005).

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A- a- 3-Maize crop
Everard (1966) found that rodents damage was to all growth stages of
the maize and was more prominent in the peripheral areas of the field than
in the center. Stem debris, remains of ears, and stilt roots of erect plant.
Lodged heads of maize or naturally growing grass were damaged, but the rat
never cut down the maize plants, Figure (3).
Fig.(3): Damage caused by rodent on maize crops.
The assessment of damage caused by rodent to maize were carried- out as
the following technique. Four maize plots each of 2 feddans were selected.
In each plots, ten samples (each containing 30 maize plants) were randomly
chosen and checked to estimate the degree of damage in their ears
according to Hamelink (1981) ,as follows:-
i I x S1 + i II x S2 + … ir x S
% Damage ears = x 100
N
Where: I = damage incidence expressed by the number of damage ears per
severity class (I= 0%, II = 25%, III = 50%, IV = 75% and V= 100% grain missing).
S = Damage severity for each class (i = 1, 2, 3, etc.). N = Total number of
sampled ears. R= repetition.

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In Egypt, Abdel-Gawad et al., (1982) estimated the damage caused by
A. niloticus (Des.) in sorghum and maize fields. Concerning damage in maize
and sorghum in the harvest stage, the most damage was clear in corncob of
the maize and in the stem top of sorghum. The damage was concentrated
beside the border and decreased toward the center of the field in both
maize and sorghum.
Abdel-Karim (1991) studies the damage caused by Arvicanthis niloticus
(Des.), in maize fields at Sharkia governorate. He found that the rats attack
maize plants at the beginning of germination and continued till harvest time
but high rate of infestation was noticed during two stages of growth, the first
one was early in the season from the second week of June till the end of
June while the second period was during the second week of August.
In Minia governorate Asran (1991) prescribed the damage by Arvicanthis
niloticus (Des.) in maize crop during the milky and dough growth stages, this
was supported by Keshta (1996) in kalubia, Beni-suef and Qena
governorates; Abdel-Hamid (1997) in Fayoum governorate; El-Nashar (1998)
in Minia governorate and Ahmed (2001) in Sohag governorate.
Losses to maize crop by large jird Meriones shawi isis (Thomas) were
about 2 Ardab/Fed., and decreased to 0.9 Ardab/Fed., during 2001 and 2002
agriculture seasons, respectively in Behria governorate (Metwally et al., 2009).
In Tanzania, It is not unusual for maize damage to exceed 80% in certain
cropping seasons and locations (Mwanjabe and Leirs, 1997).
A total yield loss of 48% of maize, sorghum, paddy, and pulses that were
in production during the 1989/90 crop season was attributed to seed
depredation by Mastomys natalensis rat (Mwanjabe et al., 2002).
Rodents cause an estimated pre-harvest loss of 15% of the annual maize
crop (Makundi et al., 1991).

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Damage due to rodents causes an estimated annual yield loss of 5–15% of
maize (corn), corresponding to about $45 million, and food which could feed
about 2 million people, (Leirs, 2003; Tables 1, 2 and 3).
The actual rodents damage to maize fields at the planting and seedling
stages in 15 fields, each 0.5 ha in size, in Morogoro, was established at the
seedling stage. The heterogeneous distribution of damage in some plots
caused variations in the accuracy of the estimates between plots, but a
sampling interval of five rows consistently produced estimates with a
variance of less than 10% (Mulungu et al., 2007).
In parts of South America, native rodents cause crop damage varying
between 5–90% of total production (Rodriquez, 1993).

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A-b- Sugar crops
Rodents may damage sugar cane and sugar beet from the time of
planting through harvesting, and cause additional damage waste by
contamination, Abdel-Gawad (1974),Abdel-Gawad et al., (1982), Ali and
Farghal (1995), Brodie and Webster(1997) , Engeman et al., (1998) and
Zhang and Zhang (1999).
A-b-1- Sugar cane crop
The assessment of damage caused by rodent on sugar cane was carried-
out as the following technique. The stalks were carefully examined to
determine the percentage of rodents damage. The percentage of damage
was calculated using the following equation:
Total numbers of damaged internodes
% Damage = x 100
Mean number of internodes in stalk x 30
In Egypt, Rat infestation reduced the juice solid contents from 12.38% to
11.64% in the top internodes, and from 18.78% to 15.655 in the bottom ones
(El-Deeb et al., 1989). The damage of the Nile grass rat Arvicanthis niloticus
(Des.), to sugar cane in Upper Egypt were 20 to 40 % reduction in yield and
30 % in final sucrose in the infested stalks of sugar cane. The bottom
infestation percentage was higher than in the top ones that may be related
to high sucrose content in the bottom internodes than in the top one
(Abazaid, 1990).The infestation percentage in the plant cane was less than in
first and second rattoons. The percentage of rodents damage for four sugar
cane varieties,G.T.54-9, G.95-19, G.95-21 and Ph8013 were higher during
first season than second season (Bakri and Al-Gendy, 2009),Figure (4).
The annual loss in sugar cane crops caused by the Nile grass rat
Arvicanthis niloticus (Des.) was estimated to be about 5-8% by weight. The
proportions of rat damaged mill able stalk averaged 23.99 % and of dead

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stalks (due to damage) 7.17 % in no baited fields while in baited fields, rat
damaged mill able stalks averaged 13.53 % and dead stalks 3.85 %
( Porquez and Barredo, 1978).
The extent of crop loss by the rodent has been estimated to the tone of
165 crores of rupees annually in sugar cane, wheat and paddy in the state of
Punjab alone (Anonymous, 1987).
The Queensland sugar, industry has recently implemented a
comprehensive integrated pest management (IPM) system to minimize crop
losses from two active rodent species, Rattus sordidus (canfield rat) and
Melomy burtoni (climbing rat). These species inflicted approximately $25M
of damage in a major outbreak in the 1999-2000 seasons (Hunt et al., 2004).
A- b-2- Sugar beet crop
The assessment of damage caused by rodent on sugar beet was carried-
out as the following technique. The roots were carefully examined to
determine the rodents damage percentage, using the following equation:
Weight of damaged roots in kg.
Damage % = x 100
Total weight of roots in kg.
In Egypt, The rodents damage was concentrated at the upper part of root,
where the sucrose was high (Ali and Farghal 1994). Losses to sugar beet by
rats were about (47.33 and 39.33kg.) and (51.54 and 43.33 kg.) during each
cultivation season respectively (Bakri and Al-Gendy, 2009), Figure (5).
Sugar beet field in North California was affected by approximately 27% of
all roots examined and account of for a 9% loss in the total production
(Salmon et al ., 1984).

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Fig.(4): Damage caused by rodent to sugar cane crop.
Fig.(5): Damage caused by rodent to sugar beet crop.

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B- Post-harvest losses: extent of the problem
After harvest the crop attains its highest value, taking into account all the
costs of producing it, processing, (packaging), storage and distribution prior
to consumption and contaminated of stored foods. The actual values of the
losses caused by rats vary by crop, variety, year, geographical location, pest
species involved, length and method of storage and climate (Gratz, 1990).
The assessment of damage caused by rodent on Storage crops was
carried- out as the following technique. Caliboso and Teter (1983) suggested
that a constant estimate of the population density is needed to assess losses
due to rodent. This could be obtained through trapping or by rougher
methods such as counting of trails. Zippin (1958) found useful method in
estimating population density in the warehouse. This method based on the
average body weight of Mus sp. (161 g.), Rattus mindanensis (160 g.), and
Rattus norvegicus (330 g.), and the daily intake of food constituted 95% of
the total diet. Thus, the daily loss can be computed by the following formula:
LR = (Pd1 x di1) + (Pd2 x Di2) + (Pd3 x Di3).
Where: Pd1=Population density of species 1 (n). Di1 = Daily intake of species(g).
Consumption and contaminated (urine and droppings) of stored
crops.
In Egypt, The estimated annual losses caused by rodents alone are about
4-10% in weight of stored grains, and the rate of damage to bags is between
10-26% (El-Lakwah,1984).
Results of investigations carried out during 1989/1991 in stores of the
Kalyubia region showed that loss in weight of cereal grains is from 0.03-
0.77% and for pulses 1.41-2.81% (El-Lakwah et al., 1993).
High loss values are obtained when wheat is heavy rodent attack. Wheat
storage period is between 4-8 months (The longer the storage period the

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higher the losses). The losses caused by handling and transport reveal that
quantities lost under the stack are from 8-46kgs/ stack with a mean value of
30.8 kg. The total quantity of wheat loss (in the various shounas of Principal
Bank for Development and Agricultural Credit), were 18769.6 tons during the
storage period 1993/94, and its economic value is equivalent to 9.8 million
Egyptian Pounds (El-Lakwah and Laborious, 1995).
In one survey of corn in a Midwestern state, 76% of about 1,000 grain
samples were contaminated with rodent droppings. Mouse droppings
outnumbered rat droppings twelve to one. A house mouse produces about
36,000 droppings in a year’s time. Mouse infestations are so widespread that
droppings and hairs often end up in many types of food commodities
intended for human use. Certain levels of rodent contamination are grounds
for condemning food commodities. Structural damage caused by rodents can
be expensive (WFP, 2008).
In Philippine, the major species affecting food storage are the Norway
rat, Rattus norvegicus, the common rice field rat, Rattus rattus mindanensis,
and the house mouse, Mus musculus. Surveys conducted in small
warehouses in the Philippines indicated losses of 40 to 210 kg of grains in
each (Rubio, 1971).
In Nueva Ecija (Central Luzon), Aganon (1981) reported that the annual
grain loss per warehouse due to rodent contamination and spillage was
estimated at 1.92 to 2.93 cavans.
In Bangladesh, rodents weighing more than 50 grams consume 15%.
Interviewing farmers on rodent damage inside houses provided an estimated
loss equivalent to US $ 29.50 for a six month period (Bruggers, 1983).
At 10.5 million households the annual losses are estimated at US $ 620
million for the entire country in houses only (Mian et al., 1984).

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Two national strategic multi-media rodent control campaigns were
organised and analysed in detail. Net profits were calculated at US $ 800,000
for each campaign, based on a single crop and season (Adhikarya and
Posamentier, 1987).
The rodent population estimated in the farmers' households averaged 8·3
mice and 2·0 rats per household. These rodents were estimated to consume
and hoard about 53 kg. of rice per farm family per year (Mian et al., 1987).
Farmer estimates of rice lost during storage to rodents ranged from 5 to
40%, with an average of 13% (±0.02 sem) estimated loss. Trials were
developed to repeatedly measure rodent impacts on stored rice and
concluded that losses could be as high as 5% of the total amount of grain
stored by a household. Losses to rodents over a three month period per
household grain store were typically 35kg; rodent losses over a year would
be enough to feed an additional person's dietary intake per household. A
further 2.5% of rice was partially eaten by rodents, significantly affecting its
nutritional value, and contamination with rodent feces could be as high as
300 droppings per kg. (Aplin et al., 2004).
5-10% of stored grain was lost to rodents over each 3-month storage
period (each household losing ˜200kg/year). Contamination with urine and feces
was also severe (200 > 1,500 droppings/ kg.) by Belmain and Shafali (2008).
Losses of rice in the Philippines were reduced from US $ 36 million to US
$ 3.5 million with the advent of organised rat control programs according to
Sumangil (1990).
In Pakistan, Ahmad et al., (1995) estimated the annual grain losses/shop
due to rats consumption, contamination, spillage, and wastage to be
740kg/shop. The annual losses would approximately about 0.3% of the
estimated 1225 million mt that move through the markets yearly. Post

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harvest losses present one of the main problems not only in rice but also in
all grain production. Losses in food crops, occurring during harvesting,
threshing, drying, storage, transportation…etc have been estimated to be
between 30 and 40% of all food crops in developing countries. If post harvest
losses are reduced, the world supply can be increased by 30-40 % without
cultivating additional hectares of land or increasing any additional
expenditure on seed, fertilizer, irrigation and plant protection measure to
grow the crop.
Rodents damaged entire upland after harvests in one of the poorest
countries in Southeast Asia. 74% of the interviewed households reported
losses between 50 and 100%, 100% rice losses were common. Maize harvest
was also severely damaged with 43% of households reporting yields of less
than 50% of expected production. Widespread damage was similarly
reported for Job’s tears, sesame, and cassava. These losses are a major
livelihood shock for rural households who rely on their own production as a
source of food and income (WFP, 2009).
The economic losses caused by insects usually do not exceed 5-10%, he
stated, but losses caused by rodents and birds can range from 5% to more
than 50% (Fachrudin, 2009), Figure (6).
Fig.(6): Stored rice contaminated with rodent feces.

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ӀӀӀ-Losses caused by rodents to fruit trees.
The common commensal pests are Rattus rattus and M. musculus
throughout the country including the islands. R. rattus along with squirrels,
Funambulus palmarum and F. tristriatus are serious pests of plantation crops
such as coconut and oil palm in the southern peninsula. F. pennanti is
abundant in orchards and gardens in the north and central plains and sub-
mountain regions (Parshad, 1999) and (Chakravarthy, 2004).
The fruit trees were carefully examined to determine the rodents damage
percentage, using the following equation:
Weight of damaged fruit in kg.
Damage % = x 100
Total weight of fruit in kg.
The amount of damage caused by rats (Rattus argentivente, Ratus
tiomanicus and Ratus diardil ) to oil palm areas on Malaysian is difficult to
estimate. In nurseries, rats have been known to chew the stem base of
young seedlings to feed on the tender bud tissues found there. Such
incidences are prevalent in field nurseries situated near forest areas or those
situated in new clearings with secondary forests nearby. Young palms
planted out in the field are not exempt from rodent attacks. If the attack is
severe, the young palms die due to collapsed fronds which have been
attacked at the base by the rats. Other than that, it has been estimated that
severe rat damage could cause between 20% to 30% damage among the
new plantings and the total fresh fruit bunch yield during the first twelve
months after maturity was 20% lower than those from palms with no
damage. If attacks are not that severe, the fronds that have been attacked
are removed to allow new fronds to grow, however the palm remains
stunted for some time. In such incidences, preventive measures need to be

25
carried out to ensure that subsequent attacks do not occur on the same
young palms which have already been weakened by earlier attacks. Mature
palms with ripe and unripe fruits alike are also subject to rodent attacks. In
the case of fruits being attacked, rodents gnaw to reach the kernel inside.
Crop losses caused by rats feeding on the mesocarp of the fruit has been
estimated to be in the region of 5% of the oil yield - and in severe cases, can
rise to between 7 to 10% of total oil production, about 165kg of oil per
hectare per year (Chung and Balasubramaniam, 2000).
During the 18 years of the trial about 43% of the trees on M.9 and B.9
rootstocks were lost, mainly because of poor anchorage, while only 12% of
those with M.9 and B.9 inter-stocks were lost, mainly because of rodent
damage (Czynczyk, 1986).
The secretive, nocturnal nature of rats means that they often go
unnoticed in a neighborhood until dooryard citrus and other fruit starts to
ripen. They then make their presence known with a vengeance. In citrus and
papaya the characteristic damage is a circular hole about the size of a
quarter or half dollar and the whole fruit hollowed out, Figures (7 and 8).
They remove whole fruits from blueberries, figs, grapes, strawberries,
Surinam cherry, loquat, and dates, so the damage is less noticeable or birds
are blamed for the missing fruit. Estimates of damage caused by Rattus
rattus to macadamia nut crops were determined from several Australian
macadamia orchards during the 1995/1996 growing season. Both the extent
and pattern of crop damage were associated with the type of adjacent non-
crop habitat. Orchards adjacent to large, temporally stable, structurally
complex habitats experienced high levels of rodent damage (mean 9.9%).
Front row trees adjacent to these stable habitats showed significantly higher
damage than trees further into the orchard, suggesting an interaction

26
between the crop and non-crop habitats. Orchards adjacent to highly
modified grasslands and other orchard blocks exhibited the lowest levels of
damage (mean 0.8%), with the damage in these areas being uniformly distributed
(White et al., 1997), (Horskins et al., 1998) and (Horskins and Wilson, 1999).
Habitat manipulation was used as a management strategy for the control
of rodent (Rattus rattus) damage in Australian macadamia orchard systems.
The total cost of the habitat manipulation was $AUD 292 per site.
Manipulation resulted in a reduction in damage of 65% within the associated
orchards. This reduction in rodent damage resulted in a saving of $AUD 980
per site. Therefore habitat manipulation was cost-effective and is a viable
strategy for the control of rodent damage in Australian macadamia orchard
systems (White et al., 1998).
Over a 3-yr period, orchard trees adjacent to the restored habitat
received 50% less rodent damage than trees adjacent to non-manipulated
habitats. A cost–benefit analysis (based on both contractor and farm rates)
of the damage reduction obtained after the initial manipulation indicated a
break-even point (based on farm rates and a nut in shell price of $2.80/kg.).
After break-even, this represents an economic benefit to growers that will
result in an additional return of approximately $4500 per annum per km of
orchard frontage (Ward et al., 2003).

27
Fig.(7): Roof rat damage to oranges.
A B
Weeds around trunk
Injury inside weed area
Fig.(8): Damage due to mice (properly referred to as "voles" but
growers simply call them "mice"), is most serious when their
normal food supply is limited. Mouse injury to fruit trees
mostly consists of girdling of trunk and roots and sometimes
root pruning ( A and B).

28
Table (1): Major agricultural rodent pest problems for food crops in selected
regions, their importance as food competitors with people, and methods of
control being applied in Africa.
Rodents species
Region
Major crop(s)
Estimated damage
Pest status
Main
control
Notes
Mastomys spp
Sub-Saharan
Africa outside
central rainforest
block
All cereals,
groundnut, tubers
Tanzania: 5–15% of harvest
annually; outbreaks >80%
Nigeria: maize 42%; rice at
seedling stage 11% during an
outbreak; sorghum 10–90%
Senegal: rice >80% during an
outbreak
Kenya 2.3–75% (mean
11.5%)
Very high
Rodenticide
See overview
in
Fiedler(1988)
Arvicanthis spp
Sub-Saharan Africa
South to Zambia
All cereals,
groundnut,
tubers,
vegetables
Same as Mastomys; in areas
where both occur, it is
difficult to distinguish
damage
by different species
Very high
Meriones shawi
Northern Africa
Cereals,
vegetables
Morocco: 40–70% losses
Very high
during
outbreaks
Tatera spp
Eastern Africa
Cereals, tubers
Low
Taterillus spp
West Africa,
Sahel
Groundnut
Senegal: 10%
Low, high
during
outbreaks
Rattus rattus
Madagascar,
locally in Africa
Maize, rice
Thryonomys sp
Rice
Nigeria: rice average 5%
Moderate
Hunting,
traps
Rhabdomys
pumilio
Eastern and
southern Africa
Cereals
Moderate
Cricetomys
gambianus
Sub-Saharan
Africa
Cereals, root
crops, fruits
vegetables cacao
Traps
Mole rats
(Heterocephalus)
spp,
Tachyorctes
spp, Cryptomys
spp)
Eastern and
Southern Africa
Root crops,
Vegetables
Very high
Traps
Squirrels
(Xerus spp)
Semi-arid sub-
Saharan Africa
Maize, coconut,
groundnut
Kenya: 9.7% of planted
maize, 5.4% of maize cobs
High
Porcupines
Sub-Saharan
Africa
Maize, coconut
High

29
Table (2): Major agricultural rodent pest problems for food crops in selected regions,
their importance as food competitors with people, and methods of control
being applied in Asia and Australia.
Rodents
species
Regio
n
Major
crop(s)
Estimated damage
Pest status
Main
control
Notes
Asia
Rattus
argentiventer
R losea
South
east
Asia
Rice
Indonesia:
10–20%
Malaysia:
2–5%
Vietnam:
>10% to>500,000 ha
Thailand:
6% lowland,
7% upland
Very high
Rodenticide
physical,
control,
fumigation,
bounty
system
Impacts on rice
production
see
Singleton(2003);
grasslands and
non- rice cereals in
China see
Zhong et al. (1999)
and
Zhang et al. (1999)
Bandicota
bengalensis B
indica, Mus
spp
South
east
Asia
Rice,
sorghum,
tuber crops
Laos: upland
crops10–15%; up to
100% in outbreak
years
Cambodia:
patchy, no data
Philippines: (patchy)
1–10%; up to 40% at
district level
High
High
Moderate
Rodenticide,
physical
control
Microtus
brandti,
Meriones
unguiculatus,
Mysopalax
baileyi
South
Asia
All cereals
and tuber
crops
India and Bangladesh:
5–10%,
some years
>50% at district level
Very high
Rodenticide,
physical
control
Cricetulus
spp,
China
Grasslands
Inner Mongolia: 15–
44% Quinghai-Tibet:
370 000 km2 badly
affected
Very high
Rodenticide
Microtus spp
All cereals,
vegetables
15 million metric tons
(5–10%)
Very high
Rodenticide,
physical
control
Rattus spp,
Myospalax
fontanieri
Australia
Mus
domesticus
All cereals
Outbreaks:
5–30% of harvest at
regional level; non-
outbreak <2%
Very high
Rodenticide
Impacts on cereal
crops see
Caughley et al.
(1994);
Rattus
sordidus
Sugarcane
US$1–2 million
annually
(2–5%)
Moderate
Rodenticide
habitat
modification
impacts on sugar
crops see
Whisson (1996);
Rattus rattus
Macadamia
nuts
Up to US$1–2 million
annually (30%)
Moderate
Rodenticide
Impacts on
macadamia nuts
see White et
al.(1997).

30
Table (3): Major agricultural rodent pest problems for food crops in selected regions,
their importance as food competitors with people, and methods of control
being applied in Europe, South and North America.
Rodents species
Region
Major
crop(s)
Estimated
damage
Pest
status
Main
control
Notes
Europe
Apodemus spp
Northwest
Europe
Cereals, non-
cereals
Moderate
See
Lund(1998)
Microtus
agrestis
Northwest
Europe
Forestry,
orchards
Forestry,
orchards
Low
Microtus
arvalis
Northwest
Europe
Horticulture,
pastures,
cereals during
outbreaks
pastures,
cereals
during
outbreaks
Moderate,
high
Arvicola
terrestris
Northwest
Europe
Tubers,
vegetables,
orchards
Tubers,
vegetables,
Moderate
South America
Holochilus spp
Argentina,
Brazil,
Uruguay
Venezuela
Rice,
sugarcane,
maize
Outbreaks:
20%
High
Rodenticide
See
Rodriguez
(1993)
Akodon spp
Bolivia, Peru
Cereals, rice,
Outbreaks:
10–90%
Very high
Rodenticide
Calomys spp
Argentina
Bolivia,
Cereals,
maize
Outbreaks:
10–90%
High
Rodenticide
Oligoryzomys
spp, Phyllotis
Argentina,
Chile, Peru
Fruits, maize,
sugarcane
Outbreaks:
12–20%
High
Rodenticide
Sigmodon spp
Colombia,
Venezuela,
Peru
Alfalfa,
rangelands
Zygodontomys
spp
Venezuela,
Colombia
Forage crops
North America
Microtus spp
Eastern US
Orchards,
vegetables,
High
Rodenticide
See
Marsh(1988)
Geomys sp,
Thomomys sp
High
Rodenticide
Spermophilus
spp
Western US
High
Rodenticide
Less detailed data is provided for Europe and North America to give a global overview. Other
species may be much more important locally as pest species. Regional variation in crop choice
and climate may affect a species’ relevance as a pest. Damage figures are rarely available and
methods of assessment are unstandardized. In most cases, more than one species in a genus
are involved in pest problems, but not all species in a genus are necessarily pests. See [sup-
plementary information on Frontiers website] for references and further details.

31
ӀV- Discussion of the article
1 - Rodents prefer grain crops and sugar crops for its palatability and its high
caloric content (Al-Gendy,1999) and (Ramsey and Wilson, 2000).
2 - Climbing rats and some rodents, prefer palm and fruit trees when its
available in the appropriate environment for survival and breeding
(White et al., 1997), (Horskins et al., 1998), (Horskins and Wilson 1999).
3 – No losses have been reported in rice crop in Egypt, due to the diversity of
food in summer and autumn seasons and to the existence of
alternatives to high-calorie contents in garbage and waste of homes and
restaurants (Al-Gendy, 2005).
4 - In many countries have not registered losses in rice, wheat and sugar
crops as they are applying a good control program to eliminate rodents
and reduce their numbers.
5 - Developing countries are recording centimes higher losses in the main
crops necessary for population daily nutrition because of the wide
spread slums that provide shelter and habitat for rodents from which to
attack fields. Moreover the lack of support for the application of control
program to eliminate rodents.

32
V-The recommendations of the article
1- Paying more attention towards reduction of losses caused by rodents
both pre-and post-harvest which can provide and safe on amount of
food sufficient enough to feed an additional person for each family all
over the world (Aplin et al., 2004).
2- Reducing post-harvest losses will results in 30% to 40% increase in
production without cultivating extra lands or increase in
expenditures on seed, fertilizer and irrigation (Ahmad et al., 1995),
and about 280 million people suffering malnutrition can benefit (Meerburg
et al., 2008).

33
VӀ- References
Abazaid, A.A. (1990): Efficiency of some common used rodenticides and
some new alternatives against Rodents in Qena Governorate. M.Sc.
Thesis. Fac. Agric., Assiut Univ., pp. 93.
Abd-el-Gawad, K. H. (1974): Ecological and toxicological studies on
commensal and house hold rodents in Assiut area. M.Sc. Thesis, Fac.
Agric., Assiut Univ., pp. 91.
Abdel-Gawad, K. H.; Salit, A. M. and Maher Ali, A. (1982): Assessment of
damage caused by rodents in some field crops. Assiut J. Agric., Sci.13
(2):73-78.
Abdel-Hamid, E.A.(1997): Some ecological and toxicological studies
on certain Egyptian rodents. M.Sc. Thesis, Fac. Agric., Al-Azhar
Univ. Cairo, pp. 162 .
Abdel-Karim, S.M.(1991): Studies on rodents in Sharkia
governorate. Ph.D. Thesis, Fac. Agric., Zagazig Univ., pp. 294 .
Adhikarya, R. and Posamentier, H. (1987): Motivating farmers for action. GTZ
Schriftenreihe, Nr. 185, 6236 Eschborn, Germany, pp. 209 .
Agnon, T.M. (1981): Surveys of rat damage in Nueva Ecija ricemill-
warehouses. M.Sc. Thesis, Univ., of the Philippines at Los Baños, pp.40 .
Ahmad, E.; Hussain, I. and Brooks, J. E. (1995): Losses of stored foods due to
rats at grain markets in Pakistan. International Biodeterioration and
Biodegradation, 36(1- 2):125-133.
Ahmed, M.Y.M.(2001): Studies on the field rat. M.Sc. Thesis, Fac. Agric.,
Al-Azhar Univ. Cairo, pp. 144.

34
Al-Fonso, P.J.(1968): Rice damage by rats in the Philippines (Asia-pacific
interchange proc.), rodents as factors in disease and economic loss.
Honolulu, Hawaii,(17-27) 53-54 .
Al-Gendy, A.A.R. (1999): Ecological and toxicological studies on rodents in
Egypt. M.Sc. Thesis, Fac. Agric., Al-Azhar Univ. Cairo, pp. 124 .
Al-Gendy, A.A.R. (2005): The economic importance of rodents. Fac. Agric.,
Al-Azhar Univ. Cairo, Nasr city, NO., 18524/2005.
Ali, M.K. and Farghal, A. L. (1994): Damage caused by rodent to sugar beet
plantation. Assiut J. Agric. Sci., 25(3):210-213.
Ali, M.K. and Farghal, A. L. (1995): Damage caused by rodent to sugar cane
varieties and juice quality in Sohag Governorate. Assiut J. Agric. Sci.,
26(4):231-237.
Anonymous (1987): 8th annual technical report of Punjab Agricultural
University centre of all India co-ordinate Research project on Rodent
Control, Punjab Agricultural University, May, 1987.
Aplin, K. ; Kamal Azad, A. ; AL Bachchu, A.; Baker, A.; Belmain, S.; Harun, M.;
Hasanuzzaman, A.; Islam, M.; Quraishi Kamal, N. ; Meyer, A.; Mian, Y.;
Mohammod, N. and Singleton, G. (2004): Ecologically-based rodent
system for diversified rice-based cropping systems in Bangladesh -
Evaluation of PETRRA-funded part of study. Natural Resources Institute,
University of Greenwich, Chatham, Kent, UK. 39.
Asran, A.A. (1991): Chronology of damage appraisal in some field crops
caused by the Nile rat Arvicanthis niloticus in Minia Governorate. 4th
Arab congress of plant protection, Cairo 1-5 Dec., Vol.ӀӀ.pp.509-513.
Asran, A.A.; El-Deeb, H. I. and El-Halafawy, M.A. (1991): rat damage to
certain crops and population density of Arvicanthis niloticus in Fayoum
governorate. Egypt. J. Agric., Res., 69(1):273-279.

35
Bakri, E.A.A. and Al-Gendy (2009):Evaluation of damage caused by the Nile
grass rat Arvicanthis niloticus (Des.), in sugar cane and sugar beet.
Minufiya J. Agric. Res. 34, (1-2):269-275.
Belmain, S. R. and Shafali, R.B. (2008): Rat management for rural
communities in Bangladesh. The Natural Resources Institute, University
of Greenwich.
Bertolino, S. (2005): Effectiveness of coypu control in small Italian wetland
areas. Wildlife Society Bulletin, 33 (2): 714-720.
Brodie, A. and Webster, K. (1997): Trees for timber and rat control in cane.
BSES-Bulletin., (59):14-15.
Brooks, J.E. and Barnes, A. M. (1972): An out-break and decline of Norway
rat populations in California rice fields. Calif. Vector Views, 19(2) : 5-14.
Brown, P. R. (2005): The effect of simulated house mouse damage to wheat
in Australia. Crop Protection, 24(2): 101-109.
Brown, P. R.; Yee, N.; Singleton, G. R.; Kenney, A. J. ; Htwe, N.M.; Myint,
M.; Aye, T.(2008): Farmers' knowledge, attitudes, and practices for
rodent management in Myanmar. International Journal of Pest
Management, 54, (1): 69 – 76.
Brown, P. R.; Singleton, G. R.; Tann, C. R. and Mock,I. (2003.): Increasing
sowing depth to reduce mouse damage to winter crops. Crop
Protection, 22(4): 653-660.
Bruggers, R.L. (Ed.) (1983): Stored commodities survey in Bangladesh. In
'Vertebrate damage control research in agriculture'. Annual report, 1983.
Denver Wildlife Research Center, Denver, Colorado, U.S.A. pp. 101.
Caliboso, F.M. and Teter, N.C. (1983): Warehouse Stock Inventory and Loss
Assessment. Maintaining Good Grain Quality. Proc. of the 6th Annual

36
Workshop on Grain Post-Harvest Technology. Puncak Pass, Bogor,
Indonesia. May 3-6.
Caughley, J.; Monamy, V. and Heiden, K. (1994): Impact of the 1993 mouse
plague. GRDC Occasional Paper Series No 7. Camberra, Australia: CRDC.
Chakravarthy, A.K. (2004): Role of Vertebrates in Inflicting Diseases in Fruit
Orchards and their Management .Disease Management of Fruits and
Vegetables © 2004 Kluwer Academic Publishers.Printed in the
Netherlands. Fruit and Vegetable Diseases (ed. K.G. Mukerji),
(1):95-142.
Chopra, G. and Parshad, V. R. (1986): Rodent damage to watermelon. Indian
Farming, 36 (3): 40- 43.
Chopra, G.; Kaur, P. and Guraya, S. S. (1996): Rodents: Ecology, Biology and
Control. R. Chand and Co. NewDelhi., 1-202.
Chung, G. F. and Balasubramaniam, R. (2000): Rat Baiting Techniques in Oil
Palm Estates Facing Labour Shortage, Incorporated Society of Planters,
Kuala Lumpur.
Czynczyk, A. (1986): Eighteen years' results with dwarf inter stocks M.9 and
B.9 on growth and cropping of two apple cultivars. International Society
for Horticultural Science ISHS Acta Horticulture 160: III International
Symposium on Research and Development on Orchard and Plantation
Systems.
El-deeb, H.I. Asran, A. A. and El-Halfawy, M.A.(1989): Effect of rat infestation
on the juice solid contents of sugar cane. 3rd Nat, Conf., of Pests & Dis.
of Veg. and Fruits in Egypt and Arab Count. Ismailia: 976-978.
El-Nashar, M.A. (1998): Ecological and toxicological studies on some Egyptian
rodents in certain traditional cultivated areas in some governorate in
Egypt. M.Sc. Thesis, Fac. Agric., Al-Azhar Univ. Cairo, pp. 62 .

37
El-Lakwah, F. (1984): Situation of storage and protection of stored
commodities against storage pests especially at farmer's level in Egypt,
XVII Int. Cong. of Ent. Hamburg, August 20-26, Abstract Volume and
Report prepared for the GTZ.
El-Lakwah, F.; Darwish, A.; El-Khayat, E. and Abdel-Latief, A. (1993): Grain
storage situation and loss caused by stored products insects in the
Kalyubia Governorate. Egypt. J. Appl., Sci., 8 (2):325-334.
El-Lakwah, F. and Laborius, A.(1995): Determination of weight losses of
wheat stored in shounas of the Principal Bank of Development and
Agricultural Credit in various Governorates in Egypt. Annals of Agric.,
Sci., Moshtohor Zagazig Univ.,
Engeman, R.M.; Tobin, M.I.; Sugihara, R.T.; Fall, M. w. (ed.) and Jackson, W.B.
(1998): Relationships of rat damage to physical and yield characteristics
of Hawaiian sugar cane. Vertebrate deteriogens. International
Biodeterioration and Biodegradation, 42(2-3):123-127.
Everard, C.O.R. (1966): Report of some aspects of rodent damage to maize in
the Western region of Nigeria. Res. Div., Min. of Agric. And Nat. Res.
Moor. Plantation, Ibadan, Nigeria, Zoology Section, pp. 23.
Fachrudin, A. (2009): Pest management in feed mills Pest Control an
agreement Seminar in Jakarta, Indonesia.
Fiedler, L. (1988): Rodent problems in Europe. In: Prakash I (Ed).Rodent pest
management. Boca Raton, FL: CRC Press. pp. 5–66.
Geddes, M.W. (1992): The relative importance of pre-harvest crop pests in
Indonesia. B Nat Res Inst Kent UK, pp. 47: 70.
Gratz, N.G. (1990): Societal impact of rodents in rice agriculture. In 'Rodents
and Rice', Ed. R. Quick, IRRI, Manila, Philippines, pp 17- 26.

38
Hamelink, J. (1981): Assessing rat damage and yield losses in sugar cane, rice
and maize. Book of rodent pests and their control. German Agency for
Technical Cooperation. Ӏ-ӀӀӀ B/5.
Hoogostraal, H.(1963): 1-A review of the contemporary land mammals of
Egypt (including Sinai),2- Logamorpha and Rodentia . J. Egypt Publ.
Health Assoc., 38:17-19.
Horskins, K. and Wilson, J. (1999): Cost-effectiveness of habitat manipulation
as a method of rodent control in Australian macadamia orchards. Crop
Protection, 18(6): 379-387.
Horskins, K.; White, J. and Wilson, J. (1998): Habitat usage of Rattus rattus in
Australian macadamia orchard systems: implications for management.
Crop Protection, 17(4): 359-364.
Hunt, W.; Dyer, B.; Kerkwyk, R.E.; Marohasy, J.; Thompson, J. and Hogarth,
D.M. (2004): System policy and infrastructure for rodent management
in the Queensland sugar industry. Conference of the Australian Society
4-7 May, pp.1-8.
Kami, H. T. (1966): Foods of Rodents in the Hamakua. Hawaii.Pacific Sci.20:
367-371.
Keshta, T. M.S.(1996):Studies on the house mouse Mus musculus L. M.Sc.
Thesis, Fac. Agric., Al-Azhar Univ. Cairo, pp.164.
Leirs, H. (2003): Management of rodents in crops: the Pied Piper and his
orchestra. Canberra, Australia: ACIAR. pp. 183–90.
Lund, M. (1988): Rodent problems in Europe. In: Prakash I (Ed). Rodent pest
management. Boca Raton, FL: CRC Press, pp. 29–33.
Makundi, R.H.; Mbise, T.J. and Kilonzo, B.S. (1991): Observations on the role
of rodents in crop losses in Tanzania and control strategies. Beitrage
Tropical landwirsch veterinary medicine 29,465-74.

39
Marsh, R. (1988): Rodent problems on the North American conti-nent. In:
Prakash I (Ed). Rodent pest management. Boca Raton, FL: CRC Press. Pp. 2–11.
Meerburg,B.G. ; Singleton,G.R. and Leirs,H. (2008): The Year of the Rat
ends - time to fight hunger! Society of Chemical Industry
Meehan, A.P. (1984): Rats and mice. Their biology and control. The Rentokil
Library, Rentokil Limited, East Grinstead, pp. 383.
Metwally, A. M.; Montasser, S.A. and Al-Gendy, A. A. R. (2009): Survey of
rodent species and assessment of damage caused by Meriones shawi
isis (Thomas) in some field crops at Bustan area. Journal of applied
Science Research, (1):42-45.
Mian, Y.; Ahmed, S. and Brooks, J.E. (1984): Post-harvest stored food losses
at farm and village level; small mammal composition and population
estimates. Bangladesh Agricultural Research Institute, Joydebpur,
Bangladesh,Techn. Rep No. 25, mimeo, pp 11.
Mian, Y.; Ahmed, S. and Brooks, J. E. (1987): Small mammals and stored food
losses in farm households in Bangladesh. Crop Protection, 6 (3): 200-203.
Mulungu, L. S.; Makundi, R. H.; Massawe, A. W. and Herwig, L. (2007):
ORIGINAL ARTICLE Relationship between sampling intensity and
precision for estimating damage to maize caused by rodents.
Integrative Zoology, (2):131-135.
Mwanjabe, P.S. and Leirs, H. (1997): An early warning system for IPM-based
rodent control in smallholder farming systems in Tanzania. Belgian
Journal of Zoology 127, 49–58.
Mwanjabe, P.S.; Sirima, F.B. and Lusingu, J. (2002): Crop losses due to
outbreaks of Mastomys natalensis (Smith, 1834) Muridae, Rodentia, in
the Lindi Region of Tanzania International Biodeterioration and
Biodegradation, 49(2-3):133-137.

40
Osborn, D. and Helmy, I. (1980): The contemporary land mammals of Egypt
(including Sinai). Published by Field Museum of National History,
London, Fieldiana Zoology, New Series, No. 5: 579.
Poche, R. M.; Main, M. Y.; Sterner, R.; Haque, M. E. and Sultand, P. (1982):
Rodent movements in wheat fields. Mammalia, 50:165–172.
Prakash, B. G. and Prakash, K. S. (1985): Estimation of rodent damage in a
hybrid rice trial. Rodent Newsl., 9 (2-4): 12-13.
Prakash, B. G.; Prakash, K. S. and Mahadevappa, M. (1986): Assessment of
rodent damage in a hybrid rice trial. Rodent Newsl., 10 (1-4) : 2-3.
Parshad, V.R. (1999): Rodent Control in India. Integrated Pest Management
Reviews, 4(2): 97-126.
Porquez, P.H. and Barredo, F.C.(1978): Rat damage survey in the Victories
mill district. Victories Agric. Research Reports.16/21:44-52.
Rabiu, S. and Rose, R.K (2004): Crop damage and yield loss caused by two
species of rodents in irrigated fields in northern Nigeria. International
Journal of pest management, 50(4): 323–326.
Ramsey, D. S. L. and Wilson, J. C. (2000): Towards ecologically based baiting
strategies for rodents in agricultural systems. International
biodeterioration & biodegradation, vol., 45 (3- 4):141.
Rao, K. and Bai, K. (2004): Rodent Exclusion. Encyclopedia of Pest
Management. Published on: 3 February 2004.
Rubio, R.R.(1971): Survey of Rat Damage in Laguna Rice Mill-Warehouses.
Unpublished Undergraduate Thesis. UP at Los Banos.
Rodríguez, J.E.( 1993): Roedores plaga: un problema permanente en
América Latina y el Caribe. Santiago, Chile: FAO, Oficina Regional para
América Latina y el Caribe.

41
Salmon, T. P. ; Gorenzel, W. P. and Lickliter, R. E.(1984): Severity and
distribution of rodent damage to sugar beet. Protection Ecology,
7(1):65-72.
Salvioni, M. (1991): Evaluation of rat (Rattus rattus) damage in rice fields in
Madagascar. International Journal of Pest Management, 37 (2): 175 - 178.
Santra, K. B.; Khalua, M. and Manna, C. K. (2001): Rodent population: Nature
and extent of damages of agricultural crops depending upon different
ecological conditions of the Gangetic plane of West Bengal. Proceedings
of the Zoological Society Calcutta, 54 (1): 68-72.
Singleton, G.R. (2003): Impacts of rodents on rice production in Asia. Los
Baños, Philippines: International Rice Research Institute. Discussion
Paper Series No 45.
Singleton, G.R. and Petch, D. (1994): A Review of the Biology and
Management of Rodent Pests in Southeast Asia Canberra: Australian
Centre for International Agricultural Research.
Singleton, G.R.; Brown, P.R. and Jacob, J. (2004): Ecologically-based rodent
management: its effectiveness in cropping systems in South-East Asia.
NJAS – Wageningen Journal of Life Sciences, 52 (2): 163-171.
Sridhara, S.(1992): Rice. In: Rodents in Indian Agriculture. Vol. 1. (Eds.
Prakash, I. and Ghosh, P. K.), Scientific Publishers, Jodhpur: 211-230.
Sumangil, J.P. (1990): Control of rice field rats in the Philippines. In 'Rodents
and Rice', Ed. R. Quick, IRRI, Manila, Philippines, pp. 35- 48.
Ward, D.; Tucker, N. and Wilson, J. (2003):Cost-effectiveness of re-
vegetating degraded riparian habitats adjacent to macadamia orchards
in reducing rodent damage. Crop Protection, 22(7): 935-940.

42
Wilson, D. E. and Reeder, D. A., eds. (1993): Mammal Species of the World:
A Taxonomic and Geographic Reference (Smithsonian Inst.,
Washington, DC).
Whisson, D. (1996): The effect of two agricultural techniques on populations
of the cane field rat (Rattus sordidus) in sugarcane crops of north
Queensland. Wildlife Res 23: 589–604.
White, J.; Horskins, K. and Wilson, J. (1998): The control of rodent damage in
Australian macadamia orchards by manipulation of adjacent non-crop
habitats. Crop Protection 17(4): 353-357.
White, J.; Wilson, J. and Horskins, K. (1997): The role of adjacent habitats in
rodent damage levels in Australian macadamia orchard systems. Crop
Protection 16: 727–32.
WFP (2008): CHT Rodent Crisis - Rapid Needs Assessment (Bangladesh).
WFP (2009): Rodent outbreaks in the Northern uplands of the Lao PDR
emergency food security assessment executive brief.
Zhang, Z.; Anguo, C.; Zhendong, N. and Xiuqing, H. (1999): Rodent pest
management in agricultural ecosystems in China. In: Singleton, G.R.;
Hinds, L.A.; Leirs, H. and Zhang, Z. (Eds) (1999): Ecologically-based
management of rodent pests. Canberra, Australia: ACIAR, 261–84Pp.
Zhang, Y. and Zhag, Y.X. (1999):Damage characteristics and control method
for the yellow rat. Chinese Journal of Vector Biology and control,
10(2):137-139.
Zhong, W.; Wang, M. and Wan, X. (1999): Ecological management of
Brandt’s vole (Microtus brandti) in Inner Mongolia, China. In: Singleton,
G.R.; Hinds, L.A.; Leirs, H., and Zhang, Z. (Eds) (1999): Ecologically-based
management of rodent pests. Canberra, Australia: ACIAR, pp.199–214.
Zippin, C. (1958): The removal of population estimation. J. Wild. Man 22 (1):
82-90.