Project of Fact Finding Survey for Poverty Reduction …...Project of Fact Finding Survey for Poverty Reduction and Sustainable Agricultural Development in Myanmar Stored rice insect

Project of Fact Finding Survey for Poverty Reduction and Sustainable Agricultural Development in Myanmar

Stored rice insect pests in Myanmar

20 January, 2016

JAICAF

Contents

Introduction

I. Investigation methods of stored rice insect pests

1. Rice sampling method 2. Direct capture method 3. Sticky trap method 4. Pheromone trap method 5. Brown rice trap method 6. Comparison between the five methods

II. Conditions of stored rice insect pest occurrences

1. Investigation spots and kinds of stored rice insect pests 2. Investigations on the mission during June and July 2015 3. Investigations on the mission during July and August 2015 4. Investigations on the mission in December 2015

III. Rice damage caused by stored rice insect pests

1. Quantitative damage 2. Qualitative damage

IV. Major kinds of stored rice insect pests

ANNEX 2

74

1. Weevils 2. Flour beetles 3. Grain borers 4. Grain beetles 5. Moths 6. Others

V. Further studies on the stored rice insect pests

1. Investigation of actual conditions on the occurrence of stored rice insect pests and native natural enemies in rice-producing districts (1) Kinds of stored rice insect pests (2) Occurrence seasons and densities 2. Ecological studies and damage (1) Ecological studies on major insect pests (2) Damage analysis 3. Developments of the management technologies on stored rice insect pests (1) Chemical methods (2) Biological methods (3) Physical methods (4) Ecological methods (5) Advancement of the integrated pest management (IPM) 4. Research and extension of the technology on stored rice insect pests

VI. Acknowledgements

Main references

目次

はじめに

Ⅰ．コメ貯穀害虫の調査方法

１．コメサンプリング法 ２．直接捕獲法 ３．粘着トラップ法 ４．フェロモントラップ法 ５．玄米トラップ法 ６．調査方法の比較

Ⅱ．コメ貯穀害虫の発生状況

１．調査地点と貯穀害虫の種類 ２．2015年６－７月派遣での調査 ３．2015年７－８月派遣での調査 ４．2015年12月派遣での調査

Ⅲ．コメ貯穀害虫による被害

１．量的被害 ２．質的被害

Ⅳ．主なコメ貯穀害虫

75

１．コクゾウムシ類 ２．コクヌストモドキ類 ３．コナナガシンクイ類 ４．ヒラタムシ類 ５．チョウ目害虫 ６．その他の害虫

Ⅴ．今後のコメ貯穀害虫研究

１．稲作地帯における貯穀害虫と天敵の発生実態調査 （１）発生種 （２）発生時期と発生量 ２．生態と被害 （１）主要種の生態 （２）被害解析 ３．管理技術の開発 （１）化学的方法 （２）生物的方法 （３）物理的方法 （４）生態的方法 （５）総合的害虫管理（IPM）の推進 ４．貯穀害虫に関する技術の研究と普及

Ⅵ．謝辞

主な参考文献

Introduction As a part of “Project of fact finding survey for poverty reduction and sustainable agricultural development in Myanmar with financial support from the Ministry of Agriculture, Forestry and Fisheries (MAFF) of Japan”, Japan Association for International Collaboration of Agriculture and Forestry (JAICAF) conducted a survey of the actual occurrence conditions, kinds and densities of stored rice insect pests in rice storehouses with the Department of Agriculture (DOA) and Department of Agricultural Research (DAR) of Ministry of Agriculture and Irrigation of Myanmar, and awakened the recognition on stored rice insect pests. In 2015, after a preliminary investigation in February, we carried out surveys on the first mission during June-July, the second mission during July-August, and the third mission in December. The technology and knowledge on the stored rice insect pests were transferred to the staff of DOA and DAR. This manual, which introduces the stored rice insect pests in Myanmar, was compiled using the data obtained by our surveys. It was also written with reference to “Main references”. We wish this manual contributes to develop the study of stored rice insect pests and improve the quality of post-harvest rice in Myanmar.

76

I. Investigation methods of stored rice insect pests

1. Rice sampling method (Photo 1)# Collect rice in rice storehouses randomly with a 200ml cup. # Investigate the kinds and number of individuals of stored rice insect pests and natural enemies in the sample. # Although this method is simple and easy without tools and materials, many individuals can be captured. # The number of individuals is shown as densities per a sampling unit (200ml of rice) # Collection of 3-5 cups in one rice storehouse is recommended.

Photo 1. A rice sampling method

2. Direct capture method (Photo 2)# Capture stored rice insect pests and native natural enemies under fixed captors (1-3 persons) and time (5-10 minutes) conditions

in rice storehouses.

# Put captured insect pests and native natural enemies into a freezer to kill and investigate the kinds and the number of individuals. # Although this method is simple and easy without tools and materials, many individuals can be captured.

Photo 2. A direct capture method

3. Sticky trap method (Photo 3)# Put the sticky trap with a handful of brown rice in rice storehouses. # Investigate the kinds and the number of individuals of stored rice insect pests captured on a sticky surface. # Small-sized traps (16cm X 10cm) with roof used in December are found better than big-sized traps (28cm X 22cm) without roof

used during June-July, 2015. # While the sticky surface of big-sized traps without roof was covered with dust and rats were captured, the sticky surface of small-

sized traps with roof was not covered in dust and no rats but geckos and cockroaches were captured. # 3 traps in one rice storehouse are recommended.

77

Photo 3. A sticky trap method (left: big-sized, middle and right: small-sized)

4. Pheromone trap method (Photo 4)# Put the pheromone trap in rice storehouses. # Use aggregated pheromone formulation for weevils in rice storehouses. # Although insect pheromone is normally species-specific, rice weevils and maize weevils are attracted by this formulation. # Since the formulation insensibly releases pheromone for one month, the trap is unsuitable for short period (a few days)

investigation as shown in our records. # Pheromone traps for various stored rice insect pests are sold in Japan. # 3 traps in one rice storehouse are recommended.

Photo 4. A pheromone trap method

5. Brown rice trap (Photo 5)# Leave a small container with 200ml of brown rice in rice storehouses for 2-4 weeks. # Investigate the kinds and the number of individuals of stored rice insect pests and native natural enemies in the container. # Although this method is simple and easy without tools and materials, several kinds of stored rice insect pests and natural enemies

can be captured. # The number of the individuals is shown as densities per a sampling unit (200ml of brown rice) # 3traps in one rice storehouse are recommended.

Photo 5. A brown rice trap method

6. Comparison between the five methodsFive methods have their own characteristics. Judging by the convenience, number of captured insect pests and costs, the rice sampling method and the direct capture method are good (Table 1). However, several methods should be used in investigations and the data needs comprehensively analyzed as kinds of stored rice insect pests captured by each method are slightly different.

It seems that a light trap method (Photo 6) maybe effective as another method for investigating stored rice insect pests which are active at night.

78

Table 1. Comparison of five methods for investigating stored rice insect pests

Photo 6. A light trap method

Method Convenience No. of capturedinsect pests

Cost Order ofevaluation

Rice sampling ◎ ◎ ◎ 1

Direct capture ◎ ◎ ◎ 1

Sticky trap ○ ○ ○ 4

Pheromone trap ○ ○ ○ 4

Brown rice trap ◎ ○ ◎ 3Note: ◎=Good, ○=Fairly good

II. Conditions of stored rice insect pest occurrences 1. Investigation spots and kinds of stored rice insect pests We carried out investigations in 16 spots (Abbreviations #1-16) as shown in Table 2. #5, 6, 7 and 8 were used as fixed investigation spots for three days on the mission during June and July 2015. #5, 7, 11, 12 and 14 were used as fixed investigation spots for four days on the mission in December 2015. Weevils, flour beetles, grain borers, grain beetles, moths, etc. were confirmed as stored rice insect pests (Table 3). Stored rice is severely damaged by weevils and grain borers. In Myanmar, major species of weevils is the rice weevil although the maize weevil also inhabits. Weevils are classified into Families of Rhynchophoridae or Curculionidae. Flour beetles eat few rice grains, but they secrete harmful material, quinone (Mondal, 1992; Hodges et al., 1996; Lis et al., 2011). Grain borers eat a lot of rice grains. Moths alike the Angoumois grain moth always occur on cereals. Lophocateres pusillus (Coleoptera) inhabit in the tropics, not in Japan. As several more kinds of the stored rice insect pests will probably be found in addition to the ones recorded in this manual, further investigations in Myanmar should be carried out.

79

Table 2. Investigation spots in 2015

Note: Abbreviations, #1-15, are rice storehouses and #16 a market.

Investigated spot Abbreviation Business Investigation season on the 1st, 2nd and3rd missions

Zeya Thiri office of DOA (Zeya Thiri TS) #1 Government office June-JulyMr. U Toe (Zeya Thiri TS) #2 Farmer June-JulyMr. U Soe Lwin Oo (Zeya Thiri TS) #3 Rice miller June-JulyMr. U Sen Bou (Zeya Thiri TS) #4 Farmer June-JulyMs. Daw Khin Mar Cho (Zeya Thiri TS) #5 Farmer June-July, July-August and DecemberMr. U Kyi Aung (Zeya Thiri TS) #6 Rice miller June-July and July-AugustCo. Aung Mingalar (Tatkon TS) #7 Rice miller June-July, July-August and DecemberMr. Kya Min (Tatkon TS) #8 Rice miller June-July and July-AugustMr. U Nyi Khin (Zeya Thiri TS) #9 Farmer June-JulyU Aung Kyam Oo (Zeya Thiri TS) #10 Farmer June-JulyCo. Yadanar (Pynmana TS) #11 Rice miller July-August and DecemberPyi Lone Chan Thar (Leway TS) #12 Rice miller July-August and DecemberMin Sat San (Pynmana TS) #13 Rice miller July-AugustDAR (Nay Pyi Taw) #14 Institute DecemberMs.Thit Thit Aung (Nay Pyi Taw) #15 Rice miller DecemberSupercenter (Nay Pyi Taw) #16 Market June-July and December

Table 3. Kinds of stored rice insect pests

2．Investigations on the mission during June and July 2015 We investigated stored rice insect pests in 11 spots (#1-10 and 16, Table 2). Among them, 4 spots (#5-8) were fixed and investigated for three days. The methods of rice sampling, direct capture, sticky trap and pheromone trap were applied. We confirmed stored rice insect pests in 6 of the 11 rice storehouses. As many weevils and flour beetles were observed in preliminary investigations in February 2015, they were also found in #5-8 (Table 4). Grain borers and moths alike Angoumois grain moth were observed as well. We found weevils from polished rice in vinyl bags, which were sold in the market (#16).

Insect pest name SpeciesWeevils Rhynchophoridae such as the rice weevil, Sitophilus oryzae, and the maize weevil,

S. zeamais （コクゾウムシ類）

Flour beetles Tenebrionidae such as the rust-red flour beetle, Triboliun castaneum （コクヌストモドキ類）

Grain borers Bostrychidae such as the lesser grain borer, Rhyzopertha dominica （コナナガシンクイ類）

Grain beetles Cucujidae such as the saw-toothed grain beetle, Oryzaephilus surinamensis ,and the flat grain beetle, Cryptolestes pusillus（ヒラタムシ類）

Moths Lepidopteran insect pest such as the Angoumois grain moth, Sitotroga cerealella （バクガ等のキバガ科、あるいはメイガ類）

Others Other insect pests, for example Lophocateres pusillus (Coleoptera)

80

Table 4. Investigations of stored grain insect pests in rice storehouses on the 1st mission (June-July, 2015)

Note: Grain borers and moths like the Angoumois grain moth were observed.

3．Investigations on the mission during July and August 2015 We investigated stored rice insect pests in 7 spots (#5-8 and 11-13, Table 2). The methods of rice sampling and direct capture were applied. We confirmed stored rice insect pests in all investigation spots (Table 5). While weevils were observed in 7 investigation spots, flour beetles, grain borers, grain beetles and Lophocateres pusillus were observed in 4-5 investigation spots.

Investigated Abbr. Date No. of insect pests spot Rice sampling Direct capture Sticky trap (28cm X 22cm) Pheromone trap

Weevils Flour beetles Weevils Flour beetles Weevils Flour beetles WeevilsMs. Daw Khin Mar Cho #5 1-Jul 0 2 1 5 Start Start Start (Zeya Thiri TS) 2-Jul 1 9 3 3 8 0 1

3-Jul 0 0 1 3 2 4 3Total 1 11 5 11 10 4 4

Mr. U Kyi Aung #6 1-Jul 0 0 0 4 Start Start Start (Zeya Thiri TS) 2-Jul No sample No sample 0 0 2 0 1

3-Jul No sample No sample 0 0 1 1 1Total 0 0 0 0 3 1 2

Co. Aung Mingalar #7 1-Jul 0 1 2 12 Start Start Start (Tatkon TS) 2-Jul 0 0 2 1 0 0 0

3-Jul 0 0 39 0 0 1 0Total 0 1 43 13 0 1 0

Mr. Kya Min #8 1-Jul 0 0 3 2 Start Start Start (Tatkon TS) 2-Jul 0 0 0 1 0 0 0

3-Jul 0 0 0 0 0 0 0Total 0 0 3 3 0 0 0

Table 5. Investigations of stored grain insect pests in rice storehouses on the 2nd mission (July and August, 2015)

Note: Lophocateres pusillus (Coleoptera) and moths like the Angoumois grain moth were observed as the others. 4. Investigations on the mission in December 2015 We investigated stored rice insect pests in 7 spots (#5, 7, 11, 12 and 14-16, Table 2). Among them, 5 investigation spots (#5, 7, 11, 12 and 14) were fixed and investigated four times for seven days. The methods of rice sampling, direct capture, sticky trap, pheromone trap and brown rice trap were applied.

Investigated Abbr. Date No. of insect pests spot Rice sampling Direct capture

Weevils Flourbeetles

Grainborers

Grainbeetles

Moths Others Weevils Flourbeetles

Grainborers

Grainbeetles

Moths Others

Ms. Daw Khin MarCho (Zeya Thiri TS) #5 5-Aug 8 0 25 0 0 4 2 1 73 1 0 14Mr. U Kyi Aung(Zeya Thiri TS) #6 28-Jul 1 0 0 0 1 0 0 0 15 0 0 0Co. Aung Mingalar(Tatkon TS) #7 25-Jan 26 2 5 0 0 14 0 0 9 4 0 7Mr. Kya Min (TatkonTS) #8 4-Aug 1 0 0 0 0 0 0 0 0 0 0 0Co. Yadanar(Pynmana TS) #11 30-Jul 0 0 33 1 0 0 2 7 1 2 0 9Pyi Lone Chan Thar(Leway TS) #12 30-Jul 1 0 0 0 0 0 0 0 10 0 0 1Min Sat San(Pynmana TS) #13 3-Aug 7 20 0 2 0 6 1 12 0 0 0 4

Total 44 22 63 3 1 24 5 20 108 7 0 35

81

We confirmed stored rice insect pests in all investigation spots. In #5, 7, 11 and 12, weevils, flour beetles, grain borers, grain beetles, moths and Lophocateres pusillus were observed (Table 6). Accumulated numbers of weevils, flour beetles and grain borers by the day are shown in Fig. 1, Fig. 2 and Fig. 3.

Fig. 1. Accumulated numbers of the weevils on the 3rd mission (December, 2015)

0.0 

20.0 

40.0 

60.0 

80.0 

100.0 

120.0 

140.0 

08‐Dec 09‐Dec 10‐Dec 11‐Dec 12‐Dec 13‐Dec 14‐Dec

200ml grains

Direct capture

Sticky trap

Pheromone trap

Acc

umul

ated

num

bers

We found weevils and moths from polished rice in vinyl bags, which were sold in the market (#16). The floor of storehouses should be kept clean like that of #14 (a storehouse of DAR). Incidentally, we observed that some individuals of weevils in Myanmar flied during daytime.

Fig. 2. Accumulated numbers of the flour beetles on the 3rd mission (December, 2015)

82

Fig. 3. Accumulated numbers of the grain borers in the 3rd dispatch (December, 2015)

Table 6. Investigations of stored grain insect pests in rice storehouses on the 3rd mission (December, 2015)

Investigated Abbr. Date No. of insect pests spot 200ml grains Direct counting Sticky trap (16cm X 10cm) Pheromone trap Brown rice trap

Weevils Flourbeetles

Grainborers

Grainbeetles

Moths Weevils Flourbeetles

Grainborers

Grainbeetles

Moths Others Weevils Flourbeetles

Grainborers

Grainbeetles

Moths Weevils Weevils Flourbeetles

Grainborers

Grainbeetles

Ms. Daw Khin Mar Cho. #5 8-Dec 1.0 1.0 6.0 0.5 0.5 0.5 0.5 1.5 0.0 0.5 0.5 Start Start Start Start Start Start Starat Start Start Start

(Zeya Thiri TS) 9-Dec 4.5 4.0 3.5 0.0 1.5 7.5 0.0 1.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 25.3 0.011-Dec 0.0 1.0 5.5 1.5 2.5 0.0 0.0 2.5 0.0 0.0 0.0 0.0 0.0 0.0 0.8 25.0 0.014-Dec 0.0 0.5 3.0 0.0 0.0 6.0 0.0 0.0 0.0 0.0 3.7 2.5 0.0 5.0 0.0 47.0 0.0 0.0 0.0 1.0 6.0Total 5.5 6.5 18.0 2.0 4.5 14.0 0.5 5.0 0.0 0.5 4.2 2.5 0.0 5.0 0.8 97.3 0.0 0.0 0.0 1.0 6.0

Co. Aung Mingalar. #7 8-Dec 4.0 0.5 21.5 0.3 0.0 6.5 0.0 9.5 0.0 2.0 0.5 Start Start Start Start Start Start Starat Start Start Start(Tatkon TS) 9-Dec 5.5 0.5 14.0 0.8 0.0 3.0 0.0 0.0 0.0 1.0 0.5 0.0 0.0 0.0 0.0 11.5 0.0

11-Dec 6.0 0.0 16.5 0.0 0.0 7.7 0.5 2.5 0.0 1.0 25.5 0.0 0.0 0.0 0.0 0.0 0.014-Dec 2.5 2.0 10.5 0.0 0.0 9.0 0.0 5.0 0.0 1.0 0.0 0.0 0.0 0.0 0.0 1.0 4.0Total 18.0 3.0 62.5 1.1 0.0 26.2 0.5 17.0 0.0 5.0 26.5 0.0 0.0 0.0 0.0 12.5 4.0 Lost trap

Co. Yadanar. #11 8-Dec 0.0 1.5 1.5 0.8 3.5 0.0 1.0 5.0 0.5 0.0 2.0 Start Start Start Start Start Start Starat Start Start Start(Pynmana TS) 9-Dec 0.5 2.5 1.0 0.8 2.5 0.0 0.0 0.0 0.0 2.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

11-Dec 0.5 0.5 3.0 0.5 1.0 0.0 0.0 20.0 0.5 0.5 3.5 0.0 3.7 1.4 0.4 2.0 0.014-Dec 0.5 3.0 0.0 1.0 1.0 1.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 3.7 0.7 3.0 0.0 0.0 0.0 3.0 0.0Total 1.5 7.5 5.5 3.1 8.0 1.0 1.0 25.0 1.0 2.5 5.5 0.0 3.7 5.1 1.1 5.0 0.0 0.0 0.0 3.0 0.0

Pyi Lone Chan Thar #12 8-Dec 2.5 0.5 1.0 0.0 0.0 6.0 9.0 0.0 0.0 0.0 0.5 Start Start Start Start Start Start Starat Start Start Start(Leway TS) 9-Dec 17.5 1.5 0.5 1.3 0.8 16.0 0.5 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

11-Dec 4.0 0.0 0.0 0.0 0.0 0.0 6.0 0.0 0.0 0.0 1.5 1.0 0.0 0.0 0.0 0.7 0.314-Dec 3.5 1.0 0.0 2.5 0.0 19.0 5.0 0.0 0.0 0.0 0.0 0.3 0.0 0.0 0.0 0.7 0.3 0.0 8.0 0.0 4.0

Total 27.5 3.0 1.5 3.8 1 41.0 20.5 0.0 0.0 0.0 2.0 1.3 0.0 0.0 0.0 1.4 0.6 0.0 8.0 0.0 4.0

DAR #14 8-Dec 0.5 0.0 0.0 0.0 0.0 5.5 0.0 1.0 0.0 0.0 0.0 Start Start Start Start Start Start Starat Start Start Start(Nay Pyi Taw) 9-Dec 0.5 0.0 0.0 0.0 0.0 14.0 0.0 0.0 0.0 1.0 2.0 0.0 0.0 0.0 0.0 0.0 0.3

11-Dec 0.0 0.0 0.0 0.0 0.0 4.5 0.0 1.5 0.0 0.0 0.0 0.3 0.0 0.0 0.0 0.0 0.314-Dec 0.0 0.0 0.0 0.0 0.0 15.5 0.0 0.0 0.0 0.0 0.0 2.0 0.0 0.3 0.0 0.0 0.3 0.0 0.0 0.0 0.0Total 1.0 0.0 0.0 0.0 0.0 39.5 0.0 2.5 0.0 1.0 2.0 2.3 0.0 0.3 0.0 0.0 0.9 0.0 0.0 0.0 0.0

Ms. Thit Thit Aung (Nay PyiTaw)

#15 8-Dec 11.5 23.0 0.0 0.0 0.0 2.5

Supercenter (Nay Pyi Taw) #16 8-Dec 1.5 0.0 0.0 0.0 2.5

83

III. Rice damage caused by stored rice insect pests

1. Quantitative damageThe investigation in rice storehouses clarified the relationship between the number of stored rice insect pests and the number of damaged rice (Fig. 4, Photo 7). The number of damaged rice increased in accordance with the increase of the number of insect pests. Damage analysis under laboratory conditions should be carried out to obtain detailed data.

Fig. 4. Relationships between numbers of insect pests and damaged rice

0.0 

1.0 

2.0 

3.0 

4.0 

5.0 

6.0 

7.0 

0.5  4.0  7.3  9.0 

No. of insecte pests / 200ml of rice

No.

of d

amag

ed r

ice

/ 200

ml o

f ric

e

Photo 7. Damaged rice grains

Sittisuang and Imura (1987) surveyed the weight loss of brown rice by rice weevils and lesser grain borers (Fig. 5). Twenty individuals and 145g of brown rice were used for each of them. After leaving brown rice with adults for 14 weeks under 30C conditions, severe weight losses by the two were observed. The damage by lesser grain borers was severer than that by rice weevils.

84

Fig. 5. Weight loss of brown rice by the rice weevil and the lesser grain borer under a laboratory condition (145g brown rice, 20 adults and 14 weeks) These figures are drawn up based on the report of Sittisuang and Imura (1987).

2. Qualitative damageStored rice insect pests cast stored rice harmful influences such as increases of temperature and moisture, bad smell, and discoloration of rice. The investigation in rice storehouses clarified the relationship between the number of stored rice insect pests and the moisture of brown rice. The moisture of rice tended to increase in accordance with the increase of the number of insect pests (Fig. 6). Damage analysis under laboratory conditions should be carried out to obtain detailed data.

0

5

10

15

20

25

30

35

40

45

Rice weevil Lesser grain borer

Weight loss (%)

Fig. 6. Relationships of numbers of insect pests and rice moisture

9.0 

9.5 

10.0 

10.5 

11.0 

11.5 

12.0 

0.5  4.0  7.3  9.0 

No. of insect pests / 200ml of rice

Mois

ture

(%) of bro

wn

rice

85

IV. Major kinds of stored rice insect pests

1. Weevils

The body length of adults is about 2-3 mm for rice weevils and 3-4 mm for maize weevils (Photo 8). Adults and larvae eat rice grains with their long mouthparts. These insects are a major stored rice insect pest. It is thought that the order as suitable food for development of larvae is brown rice, unhulled rice and polished rice.

Photo 8. Weevils (left: rice weevil, middle: maize weevil, right: weevils on rice)

Rice weevil（ココクゾウムシ） Scientific name: Sitophilus oryzae Family name: Rhynchophoridae（オサゾウムシ科）Occasionally, this insect is classified into Curculionidae（ゾウムシ科）.

Maize weevil（コクゾウムシ）

Scientific name: Sitophilus zeamais Family name: Rhynchophoridae（オサゾウムシ科）Occasionally, this insect is classified into Curculionidae（ゾウムシ科）.

The distribution is global and these insects inhabit in Myanmar, too. Adults lay eggs inside of rice grains, and hatched larvae develop within rice grains. Once damaged, the temperature and moisture of rice rise. While rice weevils inhabit only in rice storehouses, maize weevils inhabit in rice storehouses as well as the fields. Although some of them have no ability to fly, the ones in Myanmar can fly.

2. Flour beetles

The body length of adults is about 3-4 mm (Photo 9). Adults and larvae mainly eat rice powder but adults also eat some rice grains. The distribution is global and this insect inhabits in Myanmar, too. This insect secretes harmful material, quinone (Mondal, 1992; Hodges et al., 1996; Lis et al., 2011), and rice with much of them has bad smell.

Photo 9. Flour beetles

Rust-red flour beetle（コクヌストモドキ） Scientific name: Tribolium castaneum Family name: Tenebrionidae（ゴミムシダマシ科）

86

3. Grain borers

The body length of adults is about 2-3 mm (Photo 10). Adults and larvae eat rice grains. Adults lay eggs on the surface of grains. This insect is a major stored rice insect pest, and many individuals inhabit in Myanmar. Many kinds of Bostrychidae eat woods.

Photo 10. Grain borers

Lesser grain borer（コナナガシンクイムシ） Scientific name: Rhyzopertha dominica Family name: Bostrychidae（ナガシンクイムシ科）

4. Grain beetles

The body length of adults is about 3 mm for saw-toothed grain beetles and 2 mm for flat grain beetles (Photo 11). These insects eat rice powder. Saw-toothed grain borers have a sow-like thorax. Flat grain beetles have square-built thorax. These insects are minor stored rice insect pests. The distribution is global and these insects inhabit in Myanmar, too.

Photo 11. Grain beetles (left: the saw-toothed grain beetle, right: the flat grain beetle)

Saw-toothed grain beetle（ノコギリヒラタムシ） Scientific name: Oryzaephilus surinamensis Family name: Silvanidae（ホソヒラタムシ科）

Flat grain beetle（カクムネヒラタムシ） Scientific name：Cryptolestes pusillus Family name: Cucujidae（ヒラタムシ科）

87

5. Moths

The wing span of adults is about 13-14mm (Photo 12). This insect lays eggs on the surface of grains, and larvae eat rice grains. This insect damages ears of wheat in the fields and stored rice in rice storehouses. The distribution is global and this insect inhabits in Myanmar, too.

As stored rice insect pests which belong to moths, a family of Pyralidae is also known. Corcyra cephalonica（ガイマイツヅリガ）,

Plodia interpunctella（ノシメマダラメイガ）, etc are major stored rice insect pests.

Photo 12. Moths

Angoumois grain moth（バクガ等） Scientific name: Sitotroga cerealella Family name: Gelechiidae（キバガ科）

6. Others

The body length of adults is about 2-3 mm (Photo 13). This insect is a stored rice insect pest in the tropics, and inhabits in Myanmar, too. This insect is a minor stored rice insect pest. There is no Japanese name as this insect does not distribute in Japan.

Photo 13. Others (Siamese grain beetle)

Siamese grain beetle（和名なし）

Scientific name: Lophocateres pusillus Family name：Trogossitidae

88

V. Further studies on stored rice insect pests

Damages by insect pests need recognized first to improve the quality of stored rice. It is quite problematic that farmers and millers are indifferent to stored rice insect pests in Myanmar.

It is necessary to investigate the actual occurrence conditions, ecological features and damages, to develop the management methods on stored rice insect pests. Moreover, those who are concerned such as farmers, millers, rice retailers, extension officers, researchers and administrators should have a common recognition on stored rice insect pests.

In the end, the stored rice insect pest management methods should be developed based on IPM (Integrated Pest Management) aiming to contribute to the supply of high quality rice in Myanmar. Understanding of the insect pest problems by concerned parties is indispensable for the insect pest management as it requires a lot of costs and efforts.

1. Investigation of actual conditions on the occurrence of stored rice insect pests and native natural enemies in rice-producing districts The knowledge and information on species, occurrence seasons and densities of stored rice insect pests are most fundamental and important for controlling insect pests. In each administrative district of Myanmar, we investigated stored rice insect pests with several methods such as rice sampling, direct capture, sticky trap, pheromone trap and brown rice trap in elected 10 storehouses. Methods to apply should be carefully considered. The information from farmers, millers and rice retailers are also important. We should be interested in native natural enemies.

(1)Kinds of stored rice insect pests As a first stage, investigate the kinds of stored rice insect pests and native natural enemies which inhabit in rice storehouses of rice-producing districts in Myanmar. The kinds are classified as the level of family, genus and species.

(2) Occurrence seasons and densities As second stage, investigate the occurrence seasons and densities for each kind. The investigation should be carried out for three years at least.

2. Ecological studies and damageEcological knowledge, such as life cycle, seasonal changes, egg-laying, development, food habit, etc., is indispensable for establishing control methods. Therefore, investigations need carried out under storehouse and laboratory conditions.

(1) Ecological studies on major insect pests Investigate the life cycle, seasonal changes, egg-laying, developments and food habits of the major store rice insect pests. Some of the ecological features on stored rice insect pests in Myanmar were already found by our survey.

(2) Damage analysis As damage analysis, investigate the amount of rice consumption by stored rice insect pests. The relationships between numbers of insect pest individuals and rice damage of several varieties should be investigated under rice storehouse and laboratory conditions.

3. Developments of the management technologies on stored rice insect pestsControl methods can be divided into chemical, biological, physical and ecological methods. Each method has both strong and weak points.

(1) Chemical methods Investigate the efficiency of several insecticides against major stored rice insect pests. Safe and effective insecticides should be selected based on the provisions of the low of Myanmar on agrochemicals. It is also important to read the label of insecticides carefully and follow the directions.

89

(2) Biological methods Native natural enemies are expected as agents of stored rice insect pest control. Investigate the method for utilizing native natural enemies, which inhabit in rice storehouses of Myanmar.

(3) Physical methods Although expensive, building rice storehouse insect pests cannot enter is desirable as a physical method. To catch and kill are economical and basic methods.

(4) Ecological methods Investigate the environments which are difficult for rice insect pests to inhabit. The relationship between rice varieties in Myanmar and insect damages should be clarified.

(5) Advancement of the integrated pest management (IPM) The chemical method, which depends on agrochemicals like insecticides, is very effective and popular in agriculture. However, agrochemicals could have harmful effects to human beings and environments, and bring social problems as a result. As the theory of IPM was established taking it into consideration, it is now globally recognized as desirable for pest management. IPM permits to use agrochemicals, but adamantly demands proper use of proper agrochemicals. IPM should be basic to control stored rice insect pests; accordingly the technologies on “Precaution against pest occurrences”, “Judgments for controlling pests”, and “Utilizations of all suitable techniques and methods for controlling” need developed to practice IPM.

4. Research and extension of the technology on stored rice insect pestsIn our investigation of stored rice insect pests, developed technologies were transferred to all concerned parties such as farmers, millers, rice retailers, extension officers, researchers and administrators. Since the research on stored rice insect pests is carried out to contribute to the supply of high quality rice, the developed technologies should be extended to the people concerned. Incidentally, researchers should write “Research plans, basic reports and extension manuals” for uninterrupted research and extension.

VI. Acknowledgement

Japan Association for International Collaboration of Agriculture and Forestry (JAICAF) surveyed stored rice insect pests as a part of “Project of fact finding survey for poverty reduction and sustainable agricultural development in Myanmar with financial support from the Ministry of Agriculture, Forestry and Fisheries (MAFF) of Japan.” We were supported by the Department of Agriculture (DOA) and Department of Agricultural Research (DAR) of Ministry of Agriculture and Irrigation of Myanmar. We were also helped by the embassy of Japan, JICA Myanmar Office, and JICA Project on Development of Participatory Multiplication and Distribution System for Quality Rice Seeds. We were enlightened on stored rice insect pests by Dr. Osamu Imura and Dr. Akihiro Miyanoshita, Japanese entomologists. We would like to express our appreciation for the support and enlightenment.

Main references

(1) Fujiie, A., M. Otim, A. Goto and A. Godfrey (2013) Technical note on the status of rice insect pests & their natural enemies in Uganda. JICA Promotion of Rice Development (PRiDe) Project. National crops resources research institute, Uganda, p. 40.

(2) Imura, O. and H. Takeshita (1987) Loss assessment of stored rice infested with stored-product insects. Proc. 11th Int. Cong. Plant Protection. 2:274-281.

(3) Japan International Research Center for Agricultural Science (JIRCAS), Japan and Department of Agriculture, Ministry of Agriculture and Cooperatives, Thailand (2004) Stored rice insect pests and their native natural enemies in Thailand. JIRCAS International Agriculture Series No. 13. JIRCAS and Department of Agriculture, Thailand. Tsukuba and Bangkok, p. 79. (4) Hodges, R. J., R. Robinso and D. R. Hall (1996) Quinone contamination of dehusked rice by Tribolium castaneurn (Herbst)

(Coleoptera: Tenebrionidae). J. stored Prod. Res. 32: 31-37. (5) Kiritani, K. (2000) Integrated biodiversity management in paddy fields: shift of paradigm from IPM toward IBM. Integrated

90

Pest Management Reviews 5: 175–183. (6) Lis, L. B., T. Bakuła, M. Baranowski and A. Czarnewicz (2011) The carcinogenic effects of benzoquinones produced by the

flour beetle. Polish Journal of Veterinary Sciences Vol. 14: 159-164. (7) Mondal, K. A. M. S. H. (1992) Quinone secretions of flour beetles, Tribolium: problems and prospect. Tribolium information

bulletin 32: 79-89. (8) 中筋房夫・大林延夫・藤家 梓（1997）害虫防除．朝倉書店．東京．161 頁．

(9) 日本応用動物昆虫学会 編（2000）応用動物学・応用昆虫学学術用語集 第３版．日本応用動物昆虫学会．東京．236 頁．

(10) 日本応用動物昆虫学会 編（2006）農林有害動物・昆虫名鑑 増補改訂版．日本応用動物昆虫学会．東京．387 頁．

(11) 農業・食品産業技術総合研究機構 食品総合研究所 HP（2015 年８月閲覧）http://www.naro.affrc.go.jp/org/nfri/yakudachi/gaichu/ (12) Sittisuang, P. and O. Imura (1987) Damage of rough and brown rice by four stored-product insect pest. Appl. Ent. Zool.

22:585-593. (13) 安富和男・梅谷献二（1995）原色図鑑 改訂 衛生害虫と衣食住の害虫．全国農村教育協会．東京．310 頁．

The responsibility for the wording of this article: Dr. Azusa FUJIIE, Applied entomologist

＝MEMO＝

91

Trap information

I．For Stored Grain Insect Research

1．Pheromone Traps （1）Manufacturers and Distributors Fuji Flavor Co., Ltd (http://www.fjf.co.jp/jp/ecomone/product/index.html） ＊Techno Co., Ltd sells them by mail order (http://www.tt-techno.co.jp/gyoumu_seihin/59-03.html） ＊Also sold on Amazon （2）Products TORIOS® ① For Rice weevil (Set of 50)② For Rust-red flour beetle (Set of 50)③ For Lesser grain borer (Set of 50)GACHON® ④ For Rice moth＊Techno Co. sells ①～③ in a set of 50 for ￥68,250. ＊Use of ①～③ is recommended. Add ④ if there is leeway. Add one for Angoumois grain moth if possible but the manufacturer is unfound.

2．Sticky Traps （1）Manufacturers and Distributors Earth Chemical Co., Ltd (http://www.earth-chem.co.jp/top01/gokiburi/goki_hoihoi/goki_hoihoi.html) ＊Sold on Amazon, for instance （２）Products Gokiburi hoi-hoi(Set of 5 for ￥400～500)

II．For Rat Research

1．Sticky Traps (for insect pests) （1）Distributors Japan Plant Protection Association（http://www.jppa.or.jp/） ＊Maybe sold by mail order （2）Products ① Trap with roof manufactured by Sumitomo Chemical(Set of 12 for ￥3,800）② Trap without roof manufactured by Sumitomo Chemical(Set of 12 for ￥3,200）＊Although preferred by the Director General, they have less adhesive power as they are designed for insect pests.

ANNEX 2

92

2．Sticky Traps (for rats) （1）Distributors ＊Techno co., Ltd sells them by mail order (http://www.tt-techno.co.jp/gyoumu_seihin/nezumi.html） ＊Also sold on Amazon, for instance （2）Products Sticky trap for rats ( Set of 10 for ￥1,450） ＊This is produced by Shimada Corporation but some more manufacturers are expected. http://www.probuster.jp/product/01.html

93

平成 27 年度 アジアにおける貧困削減と持続的農業の推進のための技術指導事業－ミャンマー－

事業報告書

2016 年 3 月発行

作 成 公益社団法人 国際農林業協働協会

〒107-0052 東京都港区赤坂 8-10-39 赤坂 KSA ビル 3 階

TEL: 03-5772-7880／FAX:03-5772-7680

【農林水産省補助事業】ISBN978-4-908563-03-4