Annex 5.1

TABLES ON PEST CONTROL

Table 5.1.1. Categories of major rice insect pests and their regional distribution.

Insect pest	Common name	Distribution
Root and Stem Feeders Lissorhoptrus oryzophilus Chilo suppressalis Diopsis thoracica Sesamia inferens Scirpophaga incertulas Scirpophaga innotata Scotinophora coarctata	Rice water weevil Stripped stemborer Stalk-eyed borer Pink stemborer Yellow stemborer White stemborer Black paddy bug	America, Japan Africa, Asia, Australia Africa Asia Asia Asia, Australia Asia
Foliage feeders - sucking type Baliothrips biformis Nephotettix virescens1 Nilaparvata lugens2 Sogatella furcifera Sogatodes oryzicola3	Rice thrips Green leafhopper Brown planthopper Whitebacked planthopper Rice delphacid	Asia Asia Asia, Australia Asia, Australia America
Foliage feeders - chewing type Cnaphalocrocis medinalis Dicladispa armigera Hydrellia philipina Mythimna separata Nymphula depunctalis Orseolia oryzae Spodoptera mauritia	Leaf folder Rice hispa Whorl maggot Earhead cutworm Caseworm Gall midge Armyworm	Asia, Australia Asia Asia Asia, Australia Africa, Asia, Australia, America Africa, Asia Africa, Asia, Australia
Grain feeders Leptocorisa spp. Nezara viridula Oebalus pugnax	Rice bugs Green stink bug Rice stink bug	Asia, Australia Africa, Asia, Austr., America America

¹ Vector of the rice tungro virus
² Vector of the grassy stunt virus and of the ragged stunt virus
³ Vector of the hoja blanca virus

Source:
Table 5.1.2. Relative status of major pest species.

Insects

Distribution Coleoptera or beetles and Lepidoptera or moths constitute about 60% and 6%, respectively, of the nearly a thousand species of insects associated with stored products worldwide. Postharvest conditions Dried milled rice stored in warehouses or village and household granaries and containers/bags; stable environment inside warehouse favors breeding; these stored product pests can breed under low humidity and dry food (2-14% mc); limits.are 14-34oC; 28oC generally optimum with shorter life cycles at higher temperatures. Stage/time of infestation Stored grain in warehouses and small village structures, granaries, containers and bags; bulk stored grain; primary pests attack undamaged grains, complete development therein, and initiate a succession of events in which the grain is gradually consumed by a variety of other insects, fungi and bacteria. Secondary pests feed on already damaged grain. Infestations sources: cross and residual infestations, infested containers, bags and especially jute sacks, mobility by flying or crawling, habitats in uncleaned mills, threshers and combines. Main control Integrated pest management (IPM): integrates methods for effectiveness without undesirable environmental and health effects. IPM concepts: efficient warehouse design, best hygiene, minimum insecticides, complete kill and thorough inspection programme. Biological control - only limited potential due to constraints parasitoids, predators or pathogens, pheromones, host resistance, sterility. Physical control - hygiene, exclusion, drying, refrigeration, aeration, heat, hermitic and controlled atmosphere storage, ionizing radiation, inert dusts, physical shock or disturbance, and light. Chemical control - (see Table 5.2.1) - residual (structural) and space treatment, grain protectants, surface sprays, fumigation.

Table 5.1.2. Relative status of major pest species (continued).

Rodents

Distribution About four percent of stored rice and other grains is damaged by rodents. Adult rats weighing more than 50 g consume an amount equivalent to 10% of their body weight per day and those weighing less than 50 g consume 15%. While feeding, they spill 7.5 times as much as the amount they consume. Secondary losses are caused by fungi because of contamination with rodent hairs, urine and feces. Biology and ecology Have keen sense of smell, touch through whiskers and body guard hairs, hearing (males and newborns emit ultrasonic sound) and taste; movements guided by odor trails; can detect extremely minute quantities of bitter, toxic or unpleasant substances which are significant to rodent control measures. They are good swimmers and can remain underwater for up to 30 seconds, thus, they can swim through water seal in toilet; prolific breeders year round and can restore decimated population easily; a female rat can produce 32 offsprings in the field and 37 in the warehouse because of the favorable conditions in the latter; density controlled by birth, mortality, immigration and emigration factored by quality of environment and food and water availability as well as competition in case of high population density. Feeding behavior of taking food to cover (large particles or pellets or in packets and sachets) is important to consider in baiting. Postharvest conditions Damage is due to consumption, spillage, contamination and hoarding. Main control IPM - combination of any or all of the methods described below. Environmental sanitation -removal of waste grain and other debris; limit access to open water. Biological method - cats, dogs and Salmonella; indirectly by habitat manipulation such as rapid stock turn-over, first-in, first-out stock movements to disturb habitat; Physical method - Proofing by galvanized sheet metal; conical sheet on top of each post in a granary house in villages; Blocking all entry points such as wall gaps, broken windows, air bricks, along cable and through ventilator, weak foundation, up gutter pipes and under eaves, behind sliding doors and overhanging branches; rodents can gnaw almost any material softer than their incisor enamel; Trapping and baiting - traps to be placed in areas with clear signs of rodent activity; leave traps baited but unset for a few days; be wary of the rat's cautious behavior like avoiding new objects; Electric barriers are hazardous and had only limited field applications; Ultrasound devices are not entirely effective and are expensive.

Table 5.1.2. Relative status of major pest species (continued).

Rodents

Distribution About four percent of stored rice and other grains is damaged by rodents. Adult rats weighing more than 50 g consume an amount equivalent to 10% of their body weight per day and those weighing less than 50 g consume 15%. While feeding, they spill 7.5 times as much as the amount they consume. Secondary losses are caused by fungi because of contamination with rodent hairs, urine and feces. Biology and ecology Have keen sense of smell, touch through whiskers and body guard hairs, hearing (males and newborns emit ultrasonic sound) and taste; movements guided by odor trails; can detect extremely minute quantities of bitter, toxic or unpleasant substances which are significant to rodent control measures. They are good swimmers and can remain underwater for up to 30 seconds, thus, they can swim through water seal in toilet; prolific breeders year round and can restore decimated population easily; a female rat can produce 32 offsprings in the field and 37 in the warehouse because of the favorable conditions in the latter; density controlled by birth, mortality, immigration and emigration factored by quality of environment and food and water availability as well as competition in case of high population density. Feeding behavior of taking food to cover (large particles or pellets or in packets and sachets) is important to consider in baiting.

Table 5.1.2. Relative status of major pest species (continued).

Rodents

Postharvest conditions Damage is due to consumption, spillage, contamination and hoarding. Main control IPM - combination of any or all of the methods described below. Environmental sanitation -removal of waste grain and other debris; limit access to open water. Biological method - cats, dogs and Salmonella; indirectly by habitat manipulation such as rapid stock turn-over, first-in, first-out stock movements to disturb habitat; Physical method - Proofing by galvanized sheet metal; conical sheet on top of each post in a granary house in villages; Blocking all entry points such as wall gaps, broken windows, air bricks, along cable and through ventilator, weak foundation, up gutter pipes and under eaves, behind sliding doors and overhanging branches; rodents can gnaw almost any material softer than their incisor enamel; Trapping and baiting - traps to be placed in areas with clear signs of rodent activity; leave traps baited but unset for a few days; be wary of the rat's cautious behavior like avoiding new objects; Electric barriers are hazardous and had only limited field applications; Ultrasound devices are not entirely effective and are expensive. Chemical method - Rodenticides provide cheap and convenient control method, classified as acute (single-dose fast-acting poisons), chronic (multiple-dose or single-dose slow-acting anti-coagulants), fumigants, chemosterilants and chemical repellents. Acute rodenticides are extremely hazardous to man and animals and include acute poisons such as arsenic trioxide, bromothalin, fluoroacetamide, phosacetim, silatrane, sodium fluoroacetate, strychnine and thallium sulfate. The moderately hazardous chemicals include alpha-chloralose, alpha-chlorohydrine, calciferol, zinc phosphide and pyrinuron. The minimally hazardous chemicals include equill and norbormide.

Table 5.1.2. Relative status of major pest species (continued).

Birds

Biology and behavior Major bird pests belong to genera Lonchura (Family Estrildidae) and Passer (Family Plocerdae) Weavers weigh 10 to 30 g and build covered nests. They feed on rice and Echinoloa spp weed seeds, as well as corn tassels, sorghum and certain algae. Feeding times are from dawn to about 10:00 a. m. and from about 3:00 p. m. to dusk. They are abundant during harvest period and population flows the cropping pattern. They were observed to consume 30% of their body weight in rice. Prevention and control Physical method - good warehouse design, maintenance by hygiene, egg collection and pest destruction, mist nets, traps and to a limited degree, foot stickers, noise and ultrasonic disturbances. Biological method - In the field bigger predatory birds and other animals feed on weavers. Rodents and cats may also be considered as predators inside stores. some enterprising persons catch birds at night at their roosting places for food or for trade. Chemical method - Baiting with food attractive to bird species (cake or bread is universal) may be tainted with poison of avicide, but these are potentially hazardous. They should be used only when all physical and biological methods are ineffective and used with utmost care and caution. Pre-baiting for 3 to 4 days brings success. Repellents like methiocarb discourage birds from feeding on seeds. Alpha-chloralose stupefy birds without killing them but can kill at high doses.

Table 5.1.2. Relative status of major pest species (continued).

Fungi

Fungi are multicellular microorganisms having threadlike structure called hypha and sexual and asexual spores. They do not posses chlorophyll and depend on organic matter for nutrition. They are useful in fermentation such as in brewing, production of antibodies and in food processing such as baking, cheese-making and wine fermentation. However, they can cause grain deterioration. They are cosmopolitan in distribution and grow under a wide range of environment. Certain postproduction practices are favorable to fungal invasion. Storage fungi - These include Aspergillus and Penicillium which produce toxic metabolites and cause grain discoloration, produce off odors and off tastes. They are adapted to life without free water and several species invade grains with moisture contents of 13-18% in equilibrium with 70-80% RH. They usually invade seed embryos. Damage caused Decrease in germinability, altered nutritional value, heating, discoloration, caking of grains, and low milling yields. Fortunately, rice is a poor substrate for aflatoxin (level set by WHO is below 20 parts per billion for human consumption of grains and 50 parts per billion for animal consumption) production by Aspergillus flavus and A. parasiticus.

Table 5.1.3. Grain protectants currently in use.

Insecticide	In use since	Application rate (mg per kg)
Bromophos	1968	10
Chlorpyrifos-methly	1978	5-10
Dichlorvos	1966	4-10
Fenitrothion	1977	6-12
Malathion	1960	8-20
Primiphos-methyl	1969	4-8
Bioresmethrin	1975	1.0
Carbaryl	1979	5.0
Deltamethrin	-	1.0
Fenvalerate	-	2.0
Permethrin	-	2.0
d-phenothrin	-	2.0
Pyrethrins	1935	2-3

Source: Snelson, 1985 as cited by Ong, 1992.

Table 5.1.4. Insecticide mixtures in admixture treatment of paddy.

Pesticide mixtures	Application rate (mg per kg)
Pirimiphos-methyl	12
+ Permithrin	1
+ piperonyl butoxide	5
Fenitrothion	20
+ Fenvalerate	0.5
+ Piperonyl butoxide	5
Chlorpyrifos-methyl	10
+ carbaryl	8
Methacrifos	12
+ Permithrin	1
+ Piperonyl butoxide	8
Pirimiphos-methyl	12
+ Bioresmethrin	1
+ Piperonyl butoxide	8
Fenitrothion	20
+ d-Phenothrin	1
+ Piperonyl butoxide	8
Deltamethrin	1
+ Piperonyl butoxide	8

Source: Rahim Muda and Ong , 1992.

Table 5.1.4. Insecticide mixtures in admixture treatment of paddy.

Pesticide mixtures	Application rate (mg per kg)
Pirimiphos-methyl	12
+ Permithrin	1
+ piperonyl butoxide	5
Fenitrothion	20
+ Fenvalerate	0.5
+ Piperonyl butoxide	5
Chlorpyrifos-methyl	10
+ carbaryl	8
Methacrifos	12
+ Permithrin	1
+ Piperonyl butoxide	8
Pirimiphos-methyl	12
+ Bioresmethrin	1
+ Piperonyl butoxide	8
Fenitrothion	20
+ d-Phenothrin	1
+ Piperonyl butoxide	8
Deltamethrin	1
+ Piperonyl butoxide	8

Source: Rahim Muda and Ong , 1992