IJERD – International Journal of Environmental and Rural Development (2013) 4-2

Research article
erd

Resource-based Alternative Approach on Rice Bug(Leptocorisa oratorius Fabricius) Management forFood Security and Bio-safety
MARINA A. LABONITE*
Research and Development Center, Bohol Island State University, Philippines
Email: mtalabonite@yahoo.com.ph
Received 17 December 2012

Accepted 6 May 2013(*Corresponding Author)

Abstract: In the Philippines, rice bug is a serious menace at reproductive stage of ricecausing qualitative as well as quantitative losses resulting in yield reduction by 14%(PGCPP-BPI-MAF, 1986). Thus, chemical pesticides become an instant management
strategy in rice culture for many decades until even after users realized its adverse effects
on environment and human health. Though effective, various reports are made on pesticide
residues in food, soil, water, air and overall environment causing health problems(Magallona, 1985). These problems are more than lessons from the technology. Hence, theneed to seek for an effective technology that also reduces input costs while assuring supplyof safe and nutritious food for man and all useful organisms, tapping common yetunderutilized pest-repellent plant species. The Hindu (2002) reported that companion
planting with repellent and trap crops is among the safe but sure ways to manage the insect
pests of crops. Repellents are plants with strong natural aroma that can ward-off insect
pests away. This experimental research determined the usefulness of resource-basedalternative approach on rice bug management using four repellent plant species. A twofactorial randomized complete block design was employed with sites and repellent species
as factors. The indigenous repellents tested in three replicates per site were: Bamboo(Bambusa levis L.), Erect Shell (ES) Ginger Plant (Catimbium haenkei L.), Malubago(Hibiscus tiliaceus L.) and Sand Ginger (Kaempferia galanga L.) with one control
treatment as check. The statistical analysis revealed that the repellents tested were all
effective in reducing rice bug population and infestation compared to the control, however,Bamboo and Sand Ginger are the most significantly effective. Findings imply that
resource-based approach using repellents is efficient in reducing rice bug population andinfestation, thus, it is valuable in preventing its yield loss in producing safe food and in
making the rice agro-ecosystem safe for the useful organisms.
Keywords resource-based alternative approach, pest management, food security,
bio-safety, chemical approach in pest management, repellents

INTRODUCTION
Rice grain is an important human food in many parts of the world but the plant is a host of various
insect pests like rice bugs. Heinrich (1985) observed that rice bugs nymphs are more active feeders
than adults but the latter cause more damage as they feed for a longer period of time. Feeding may
contaminate grains with pathogens that cause discoloration or pecky rice of impaired quality andsusceptibility to breakage during milling. To avoid this, farmers resort to pesticide sprays when rice
bugs are in a damaging stage and state.
However, the World Bank (2005) warned that if mismanaged, most pesticides can lead to crop
losses and pose a risk to human health and the environment. This includes the cost incurred due topesticide clean-up, cost related to human health and cost incurred due to increase in pesticide
resistance in insects and disease vectors and destruction of natural enemies of pest species, thatmay result in lost value in agricultural produce. Hence, there is a need for an alternative approachthat assures safe and nutritious food for man and all useful organisms.

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Mihindo (2002) asserted that humankind has become more conscious on the fragility of theearth in the face of technological development. The conventional farming technology has
precipitated many of our problems as people are left with a depleted and abused environment anddeepening moral apathy. Success in development is more likely to be achieved when traditional
knowledge systems are fused with modern technology.
Among the indigenous, safe but sure ways to manage insect pests of crops is companion
planting with repellent crops (Hindu, 2002). Repellents are plants with chemical properties to ward
off pests away. However, no data are available that show the effectiveness of these species to ricebugs, hence, this study was done.
The experiment aimed to determine the effects of indigenous repellent species on rice bug
population, infestation and yield of rice. Being proven effective, these plant genetic resources shallbe conserved and utilized as an alternative approach on rice bug management for food security andbio-safety.
OBJECTIVE
The main idea of this research was to determine the usefulness of a resource-base alternative
approach using indigenous repellent plant species on rice bug management. Specifically, the study
was aimed for the following objectives:
1. To assess the usefulness of Bambusa levis L., Catimbium haenkei L., Hibiscus tiliaceus L. andKaempferia galanga L. in resolving rice bug infestation
2. To identify the repellent species that is significantly effective in minimizing rice bug populationand infestation
3. To evaluate the effect of indigenous repellents on the yield of treated crops and4. To find out the interaction of factors particularly the site and repellent species on the infestationof rice bugs.
METHODOLOGY
Participatory on-farm experimentation was employed with the cooperation of farmers in fourmunicipalities with natural growth of repellent species: Bilar, Pilar, San Miguel and Tubigon inBohol, Philippines. A two-factorial randomized complete block design (RCBD) with three
replicates was adopted. Sites and the botanicals are the two factors studied. Four indigenous
repellent species were tested with one control treatment as check with no repellents used. The
repellent Bamboo (Bambusa levis L.) locally named Butong; Erect Shell (ES) Ginger Plant(Catimbium haenkei L.) or Tagbak; Malubago (Hibiscus tiliaceus L.) or Mabago; and Sand Ginger(Kaempferia galanga L.) or Kiso were used.
The rice crop host of the rice bug was grown following recommended cultural management
practices except on pest management. To confine the rice bug/test pest and facilitate data collectionthat measure the effectiveness of the repellents, a mesh net enclosure at 1.5 m high was establishedin all plots in four sites before heading stage of rice started.
Data collection was done weekly in all plots in four sites in four consecutive weeks. The data
gathered were rice bug (nymphs and adults) population, number of infested grains per panicle using
10 randomly selected panicles and the yield of rice in kilograms at 14% moisture content per plotper block. To determine the significance between the treatments, all data gathered were analyzed
using analysis of variance (ANOVA). The same data were subjected to further test of significanceusing Tukey’s Honest Significant Difference (HSD) Test.

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RESULTS AND DISCUSSION
Usefulness of repellent species in reducing rice bug population
The average population of rice bugs is presented in Fig. 1. It reveals a fluctuating trend. The data
imply that Bamboo was very effective and useful in reducing the rice bug population, followed bySand Ginger, ES Ginger Plant and Malubago as the least effective. Though Malubago was lesseffective, data still indicated that it has much lower rice bug count than the Control.

Rice Bug Population

20.00
15.00

1 Week

10.00

2 Weeks

5.00

3 Weeks
4 Weeks

0.00

Repellent Species

Fig. 1 Average rice bug population per repellent species in all sites
The ANOVA on the rice bug population gives a highly significant difference between
repellents, between sites and in its interactions. This means that rice bug population in theexperiment was affected by the significant effects of each repellent used and by the varied
conditions of the study sites.
Table 1 Tukey’s HSD Test on rice bug population as affected by repellent species
RICE BUG POPULATION
1st Week
2nd Week
Repellents
SubsetSubset12
12
BambooB. levis
5.17
4.08
Sand Ginger
K. galanga
7.58
7.58
5.75
ES Ginger
C. haenkei
8.67
8.67
4.83
Malubago
H.tiliaceus
10.17
10.17
6.75
6.75
Control
14.42
11.33
Significant
0.2760.083
0.507
0.095
* Means within the same subset are not significant to each other.

3rd Week
Subset
12
4.42
4.33
5.66
5.66
4.25
10.00
0.905
0.120

4th Week
Subset
12
6.92
6.92
9.33
10.67
18.25
0.168
1.000

Table 2 Tukey’s HSD Test on rice bug population as influenced by site
RICE BUG POPULATION
1st Week
2nd Week
3rd Week
Sites
Subset *Subset *Subset *
12
1
2
1
2
Bilar
11.53
11.33
2.80
Pilar
8.47
8.47
5.53
11.39
San Miguel
3.00
4.13
4.60
Tubigon
13.80
5.204.13
Sig.
0.096
0.107
0.776
1.000
0.620
1.000
* Means within the same subset are not significant to each other.

17.40

4th Week
Subset *2316.73

11.87
5.67
0.601

1.000

1.000

Table 1 and Table 2 show the Tukey’s HSD Test of significance on the rice bug population.
Table 2 shows a similar weekly trend of significantly lower rice bug population for Bamboo-treatedcrops ranging with only 4.08 to 6.92 bugs over the other repellents and the control which have

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higher average count ranging 10.00 to 18.25 bugs. The two Ginger species are also showing lower
bug population with 4.33 to 7.58 for Sand Ginger; and 4.83 to 9.33 bugs for ES Ginger Plant
compared to the control. Table 3 illustrates the significant and constant influence of San Miguelsite on the effectiveness of the repellents in reducing rice bug population ranging from 3.00 to11.87 bugs compared to other sites, though Tubigon and Pilar follow the trend while Bilar’s
influence on the effectiveness of the repellents came only on the last two weeks.
Effective repellents in minimizing rice bug infestation
The rice bug infestation in terms of average number of rice bug-infested grains per site perrepellent is presented in Fig. 2. The data indicate that rice bug infestation was consistently low in
the Bamboo-treated plots and consistently high in the Control plots. This implies that Bamboo is avery effective controlling species for rice bug, and thus, can be used in its management while
producing a safe food and securing the agro-ecosystem for all life forms. The data also disclosedthat in all sites, Bamboo is an effective repellent for rice bug management as it reduced its
infestation better than the other species wherever it was. However, the other three repellent species
gave better protection than the Control.
Table 3 shows that rice bug infestation in repellent-treated crops is significantly different
compared to the Control at 5% level. However, the difference in infestation between sites is highly
significant at 1% level, so do with the interactions of the species and sites. This analysis implies
that the degree of effectiveness of the repellents is not only governed by the inherent quality ofeach species itself but also by the site where the repellents are used. Therefore, the efficiency of thespecies depends on the area where it will be used as also shown in Fig. 2 where B. levis has
significantly reduced bug infestation in Pilar, San Miguel and Tubigon but not in Bilar while K.
galanga gave better protection to rice in Tubigon and San Miguel but not as effective as in othersites, thus, one species will not work efficiently in all areas.

Rice Bug Infestation/
Number of Infested
Grains300200

Expeiment Site

100BilarPilar
San Miguel
Tubigon0

Repellent Species

Fig. 2 Average rice bug infestation per repellent species per site
Table 3 The ANOVA on the rice bug infestation per repellent per site
Sources of Variation
Repellent Species
Site
Repellent Species x Site
C. V. = 16.20%* significant at 5% level

F-Value
7.669
12.733761.972

Significance*.003**.000**.000** highly significant at 1% level

The Tukey’s HSD Test on rice bug infestation shows that all repellents had significantly lower
infestation compared to the control. As to site, Rice bug infestation was significantly lesser in San
Miguel and Tubigon than in Pilar and Bilar implying that rice bugs activity is also influenced byrice environments.

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Influence of the repellent species on yield of rice

Yield of Rice, kg

Both nymphs and adult bugs suck the milky white endosperm of rice grains at milking stage. The
removal of milky sap usually results in smaller grains causes yield reduction. Figure 3 shows thatin every site, rice plants treated by each species produced closely similar yield but untreated plants
had lower harvest. Findings impart that the use of repellent species can improve rice yield via theprotection against bugs it provided the crop.

21.5

Experiment Site

Bilar

1

Pilar

0.5

San Miguel

0TubigonRepellent Species

Fig. 3 The average yield of rice, in kilograms, per repellents species per site
The analysis of variance on yield in Table 4 shows a significant degree of difference in yield
between repellent species but a highly significant variance between sites, and on the interaction
between site and species. This implies that yield was significantly influenced by site factor and by
the repellents themselves. It also indicates that rice yield differed depending on the site and on therepellent species.
Table 4 Analysis of variance on rice yield of test crop
Sources of Variation
Repellent Species
Site
Repellent Species x Site
C. V. = 7.21%

F-Value
4.559
88.9313659.681* significant at 5% level

Significance*.018**.000**.000** highly significant at 1% level

The results of the Tukey’s HSD Test on yield of test crop revealed that among repellent
species, ES Ginger Plant and Malubago are not significantly different to each other and the Control,
but these had significantly lower in yield than those with Bamboo and Sand Ginger.
The test also illustrates a highly significant degree of difference in yield between sites. The
result also imparted that aside from the effects of the repellents used; the site factor somehow
caused a significant difference on the yield of the crop as rice is a site-specific crop.
CONCLUSIONS
Based on the data gathered in this experiment, the following conclusions were made:1. Bamboo (Bambusa levis L.), ES Ginger Plant (Catimbium haenkei L.), Malubago (Hibiscustiliaceus L.) and Sand Ginger (Kaempferia galanga L.) are useful in resolving rice bug infestation,these can be an alternative approach in rice bug management.
2. All the four repellent species are effective in reducing rice bug population and infestationcompared to the control, however, Bamboo and Sand Ginger are the two most valuable species.
3. The effect of the repellent species on the yield of the treated crops was significantly higher
especially for Bamboo and Sand Ginger but those with ES Ginger Plant, Malubago and the control
had similar lesser harvest.

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4. There was a significant interaction of between the repellents and sites on the infestation of rice
bugs as evidenced by the effect of Bamboo that significantly reduced bug infestation in Pilar, San
Miguel and Tubigon but not in Bilar. It is showing that its repelling performance of Bamboo is not
only the function of the species but also of the site.
5. Since Bamboo and Sand Ginger are significantly effective for rice bug management, theserepellents should be conserved for food security and bio-safety. To promote conservation, it should
be used, protected and domesticated.
ACKNOWLEDGEMENT
The author highly recognizes the active participation and cooperation of the farmer-partners in thefour experiment sites and the BISU administration for the permission and financial support.
REFERENCES
Heinrichs, E.A., Reissig, W.H., Litsinger, J.A., Moody, K., Fiedler, L., Mew, T.W. and Barrion, A.T., 1986.
Illustrated Guide to Integrated Pest Management in Rice in Tropical Asia. International Rice ResearchInstitute, Laguna, Philippines.
Magallona, E. 1980. Pesticide management. Businessday Corporation, Inc. Makati, Metro, Manila.
Philippine. 17-18.
Mihindo, N. 2002. Organic agriculture in Kenya. Fusion of Science and Traditional Knowledge, Kenya
Institute of Organic Farming. Nairobi, Kenya.
The Hindu, 2002. Herbal pesticides. (http://www.thehindu.com/todays-paper/tp-features/tp-sci-tech-andagri/a-farmer-develops-a-herbal-pest-repellent-after-suffering-from-chemicalpesticides/article671747.ece)
The Hindu, 2002. Companion planting to manage crop pests.
(http://www.hindu.com/thehindu/seta/2002/08/22/stories/2002082200140300.htm)
PGCPP-BPI-MAF,1986. Malate, Ministry of Agriculture. Manila,Philippine. 62.
World Bank, 2005. Sustainable pest management. Achievements and Challenges. World Bank Publishing
Center.Washington D.C., USA.

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