Pink stem borer

সূচীপত্র

পরিচিতি
ক্লাসিফিকেশন
বণ্টন এবং অবস্থান
শণাক্তকরণ
চিহ্নিতকরণ এবং রোগ শণাক্তকরণঃ
বাসস্থানঃ
জীবনচক্রঃ
ক্ষয়ক্ষতিঃ
সাধারণ লক্ষণ এবং উপসর্গ
ক্ষয়ক্ষতির লক্ষণ
এটি কেনো গুরুত্বপূর্ণ?
ব্যবস্থাপনা
প্রচলিত প্রক্রিয়া
জৈবিক নিয়ন্ত্রণ
রাসায়নিক প্রক্রিয়া
বিধিনিষেধ
জিনোম সিকুয়েন্স
প্রকাশনা
তথ্যসূত্র

পরিচিতি

Pink stem borer; also known as the Asiatic pink stem borer or the purple stem borer. Sesamia inferens, the Asiatic pink stem borer, gramineous stem borer, pink borer, pink rice borer, pink rice stem borer, pink stem borer, purple borer, purple stem borer or purplish stem borer, is a moth of the family Noctuidae. The species was first described by Francis Walker in 1856.[1] It is found from Pakistan, India, Sri Lanka, Myanmar to Japan and the Solomon Islands. It is a polyphagous species and a major pest in many crops worldwide.

English name Pink stem borer

Bangla name গোলাপি মাজরা পোকা

বৈজ্ঞানিক নাম Sesamia inferens

ক্লাসিফিকেশন

Domain: Eukaryota
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Lepidoptera
Superfamily: Noctuoidea
Family: Noctuidae
Genus: Sesamia
Species: S. inferens
Binomial Name: Sesamia inferens (Walker, 1856)

Synonyms:
Leucania inferens Walker, 1856
Leucania proscripta Walker, 1856
Sesamia tranquilaris Butler, 1880
Nonagria gracilis Butler, 1880
Sesamia albicillata Snellen, 1880
Nonagria innocens Butler, 1881
Sesamia creticoides Strand, 1920
Sesamia kosempoana Strand, 1920
Sesamia sokutsuana Strand, 1920
Semasia hirayamae Matsumura, 1929

বণ্টন এবং অবস্থান

It is found from Pakistan, India, Sri Lanka, Myanmar to Japan and the Solomon Islands [1][4]. Southern Asia and northern Oceania [5].

পোষক পরিসীমা
The larvae mostly feed on Gramineae species, including Coix, Echinochloa, Oryza, Panicum, Saccharum, Setaria, Triticum, Zea and Zizania [1]. Rice, maize, millet, sorghum, sugarcane, wheat, and many grasses and some sedges, e.g., Coix lacryma-jobi (Job’s tears), Echinochloa colona (jungle rice), Panicum repens (torpedo grass), Setaria pumila (yellow foxtail), and others.[2]. Rice, millet, sugarcane, sorghum, wheat and maize [5].

শণাক্তকরণ

Egg: Eggs are almost round, creamy-white, later turning pink and black before hatching.
Pupa: Pupae are up to about 18 mm long, brown to yellowish-brown with a wrinkled frontal region of the head and cremaster with four large and two small spines.[6]
Larva: Larva smooth and shiny and lack obvious hairs or markings. Color variable but usually cream white with a distinctive pink suffusion. The head and prothoracic shield are brown. The dorsal part of the last abdominal segment bearing the anus is yellowish brown. Mature larvae are between 30–40 mm long, pink with buff and pink dorsal markings and a brown head. The larva is pale yellow with pale to purple tinge; head reddish brown; length 20-26 mm.
Adult: Its wingspan is about 28 mm. Hindwings with veins 3 and 4 arise from the cell. Antennae of male ciliated and simple in female. Body ochreous. Forewings with a red-brown suffusion along the median nerve and veins 2 to 5. A sub-marginal dark line present. Cilia paler. Hindwings are whitish.[5]. It is a robust moth with pale yellow brown body, head and thorax have a thick brown hair tuft. Wingspan: male, 16-20 mm; female, 20-31 mm.

চিহ্নিতকরণ এবং রোগ শণাক্তকরণঃ

[NO INFORMATION AVAILABLE]

বাসস্থানঃ

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জীবনচক্রঃ

Eggs are laid between the leaf sheaths and stem, up to 100 in rows; they are almost round, creamy-white, later turning pink and black before hatching. Often, the larvae disperse onto nearby tillers after hatching. They are white at first, but when mature deep pink with an orange head, and 25-35 mm long. Pupation occurs in a larval tunnel, but it can occur between leaf sheath and stem. If in a tunnel, the larvae cut an exit hole for the adult. Usually the external opening of the exit hole is covered with a fine web and cannot be easily seen from the outside.
Adults have a pale yellow-brown body, with thick brown tufts of hair over head and thorax. Wingspans of males are from 28 mm male, and females from 35 mm. Forewings are light brown, hindwings are whitish. The antennae differ between the sexes: male antennae are feather-like, females antennae are long and thin. Adults are nocturnal and strong flyers. The life-cycle is about 55 days in tropical countries, and there may be six generations a year.

ক্ষয়ক্ষতিঃ

Pink stem borer Sesamia inferens is a polyphagous pest attacking various graminaceous crops like sorghum, pearl millet, finger millet, wheat, rice, oats, barley, sugarcane and some grasses. It is the serious pest of almost all the cereals by attacking the crops at various stages and causing severe damage and yield losses. Sesamia inferens is considered one of the least destructive of the group that attack rice. Outbreaks in rice are usually late in the crop, and occur when sugarcane and maize are growing nearby and become infested.
In Asia, the most destructive and widely distributed stem borers are the yellow stem borer, Scirpophaga incertulas, the striped stem borer, Chilo suppressalis, the white stem borer, Scirpophaga innotata, the darkheaded stem borer, Chilo polychrysus, and the pink borer, Sesamia inferens. Rice plants can compensate for the damage caused by stem borers up to the stage of maximum tillering; however, infestation during panicle initiation and ear emergence, can cause a loss in yield.

সাধারণ লক্ষণ এবং উপসর্গ

Look for deadhearts and whiteheads at the vegetative and flowering stages, respectively. Look for eggs between leaf sheaths and stems, and frass, larvae and pupae in the stems. It is suggested (CABI) that the presence of eggs would be the most useful to monitor, and all stem borer species should be counted. A threshold of 1-2 egg masses per sq.m. during i) stem elongation, and ii) during panicle extension would warrant action.
Feeding occurs within the rice stem or base of the panicle. When a stem is severed it wilts causing a deadheart. Feeding at the base of the panicles often causes the panicle to be cut leading to a wilted panicle called a whitehead. Exit holes along the tillers may be visible at close inspection. These symptoms are common for most rice stem borers and not unique to S. inferens.

ক্ষয়ক্ষতির লক্ষণ

The caterpillars mainly bore into rice stems or the base of the panicle. After infection, the stem becomes wilted causing deadheart. Panicle attack leads to the panicle to be cut leading to a state called whitehead. Symptoms are mostly similar to other stem borers and hence closer look required to control the attack [1]. The larvae tunnel into the stems towards the base of the plant, causing it to wilt and die, a condition known as ‘deadheart’. The stems are easily pulled out. Feeding at the base of the panicles may prevent emergence, or result in white unfilled grain of those that have emerged, a symptom known as ‘whitehead’.

In a nutshell:
Plants/Inflorescence/wilt
Plants/Stems/dead heart
Plants/Stems/internal feeding
Plants/Stems/wilt
Plants/Whole plant/dead heart

এটি কেনো গুরুত্বপূর্ণ?

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ব্যবস্থাপনা

The community-wide practices act to prevent colonization and build-up, and have the greatest potential to minimize infestation. These include planting cultivars each season with the same maturity class and planting synchronously between fields. Rice cropping intensity is limited to two crops per year over the area and if irrigation allows a third crop it should be a non-host species such as field legume. Harvesting has a devastating effect on stem borers particularly if the straw is destroyed and the remaining stubble ploughed under.
Early planting within a contiguous area such as an irrigation turnout generally escapes damage. Using well timed and optimal levels of nitrogen and balanced fertilizer also aids a crop to compensate from damage even though it may increase the overall stem borer density. Good crop husbandry such as thorough land preparation, prompt weeding, and vigilant water management ensure vigorous crop growth and ability to tolerate stem borer damage. Early planting will usually cause the crop to escape the period of peak population build-up. The traditional and more labour intensive practices used against stem borers (Litsinger, 1994) are not particularly effective against S. inferens.

BIOSECURITY
Countries not yet infested by the pink stem borer should consider all likely pathways for entry, and apply quarantine measures accordingly. Many countries throughout Asia, Africa, the Americas and Oceania are at risk. Pathways of introduction are likely to be via produce contaminated by pieces of stem of the many hosts infected by larvae or pupae.

প্রচলিত প্রক্রিয়া

Cultural practices like crop rotation mechanisms, reducing water levels are also used in controlling. Mechanical controlling using hand picking and pheromone traps are used. Sesamia inferens usually occurs with other rice stem borers, e.g., Chilo and Scirpophaga species and are controlled by the same measures applied to them.

Before planting:
Handpicking is not practical as the eggs are hidden between leaf sheath and stem.
Prepare the land thoroughly ensuring vigorous plant growth when planted, and to destroy larvae and pupae from a previous crop.
Plant at high density to compensate for damage that may occur.
Rotate rice with non-host crops, e.g., legumes।
During growth:
Try to synchronise planting in any area, avoiding overlapping crops and preventing pest populations moving from harvested to standing crops. Additionally, choose varieties with similar times to maturity.
If the crop is seasonal, plant early. Two early-maturing crops have been found to be less damaged than a single late-maturing variety.
If irrigating, raise the level of the water from time to time to submerge the eggs on the lower parts of the plant.
Weed as soon as required to promote good crop growth.
Cut out the stems with deadhearts and remove from the field. Destroy the larvae or burn the stalk. Note, this is labour intensive and not very effective as the pest may already have left.
Apply nitrogen fertilizer in split applications: check local recommendations for rates and timing.
After harvest:
Harvest crops at ground level to remove the larvae in the stubble.
Plough remaining rice stubble into the soil to kill larvae and pupae, and avoid leaving unharvested plants. Alternatively, irrigate the field, if that is possible.
Remove or plough in weeds (grasses and sedges), which may be alternative hosts.

জৈবিক নিয়ন্ত্রণ

Natural enemies such as parasitoides are very effective and nature loving controlling measures. The tachinid fly Sturmiopsis inferens was also once used, but is now not effective due to their low abundance.

NATURAL ENEMIES
There are many predators (e.g. grasshoppers, crickets and ladybird beetles) and parasitoids that attack the pink stem borer. Parasitoids of eggs, larvae and pupae. The egg parasitoids Telenomus, Tetrastichus, and Trichogramma are the most important. Taiwan and the Philippines have introducted the tachnid fly, Stumiopsis inferens. However, CABI’s conclusion is that further introductions are probably not necessary as most countries have sufficient: importantly, the aim should be to conserve those that exist by limiting insecticide use. But note, biocontrol at the egg stage needs to be very high because the moth reproduces rapidly. Every life stage of S. inferens is vulnerable to attack by natural enemies. Once the eggs have been laid behind the leaf sheaths, the factors that will most reduce the stem borer population are natural enemies. Because of their fecundity, S. inferens populations will increase even if 90% of the population dies during the crop season. For a population to decline, more than 99% of the eggs laid must fail to reach the reproductive stage.
Classical biocontrol has been carried out in Taiwan and the Philippines with the introduction of the tachinid parasitoid Sturmiopsis inferens from India (Kamran and Raros, 1971). Even though the species became established, this method has not been highly successful as studies have shown that there are already many natural enemies of S. inferens in paddy fields and the effect of one more, even as effective as Sturmiopsis, will not be noticed against this indigenous pest. Conservation of natural enemies is the most practical tactic. For example, Sturmiopsis populations were hard to establish in areas where prophylactic insecticide applications occurred (Kamran and Raros, 1971).

RESISTANT VARIETIES
Modern rice varieties that are relatively thin-stemmed, short, high tillering, and early maturing, may result in less damage from this moth, and stem borers generally. This aspect is important as well-grown, vigorous crops can withstand 20% deadhearts and 10% whiteheads before yeild is affected.

Breeding programs have screened for resistance to rice stem borers but have not focused on S. inferens. Accessions and cultivars have been screened in the field and a number of lines have been listed by Khan et al. (1991) as being resistant to S. inferens from the results of field evaluations (Pathak, 1971; Bhatt et al., 1984; Garg, 1984). The levels of resistance, however, are only quantitative and high levels of resistance have not been found. Plant type, however, can have a broad effect on all stem borers. Short-stature, high tillering, early-maturing (110-125 days) plant types offer the greatest reduction to population build-up and damage. Short-stature cultivars reduce the highly susceptible periods of tiller and panicle elongation. Deepwater rice cultivars which elongate several meters are therefore highly susceptible. First-instar larvae need to bore into tillers and panicles in order to survive and they have the greatest chance during elongation when silica, the plant’s natural defense, is less densely packed. The longer it takes first-instar larvae to bore into a tiller the more chance natural enemies have in finding it. The larvae may also die of starvation if it cannot enter. First-instar larvae of S. inferens are a little larger than other stem borers and therefore take a shorter time to bore into a tiller. If one panicle is severed, the assimilate can be diverted to other panicles which still have unfilled grains.

Recent advances in biotechnology have raised hopes for the development of a highly resistant transgenic rice variety against stem borers. The incorporation of an insecticidal proteinase inhibitor gene into rice plants has been used for this purpose. The fifth generation of transgenic japonica rice plants containing the potato proteinase inhibitor II gene (pin2) showed increased resistance against S. inferens (Duan et al., 1996). Small scale field tests also showed that transgenic rice plants expressing the cowpea trypsin inhibitor (CPTi) gene had increased resistance against S. inferens and Chilo suppressalis (Xu et al., 1996).

রাসায়নিক প্রক্রিয়া

In chemical control, BHC, DDT, fenthion, fenitrothion, quinalphos, phosphamidon sprays and granules of lindane are used. Eggs can be eliminated by introducing Trichogramma minutum and Telenomeus species. Apanteles flavipes, Bracon chinensis and Sturmiopsis inferens are effective against caterpillars, whereas Xanthopinpla species and Tetrastichus aygari are used in pupal stages. It is unlikely that chemical control would be effective because eggs are laid between the leaf sheaths and stem and difficult to reach. Systemic products might have greater impact, but are likely to be more expensive, and perhaps uneconomic. There is also the risk of destroying natural enemies. If chemicals are needed:
Use abamectin, a natural fermentation product from a bacterium.
In Fiji, diazinon and bifenthrin are recommended for (unspecified) stem borers.
Chlorpyrifos and fipronil, have also been recommended (for all stem borers), but note that chlorpyrifos is an organophosphate insecticide, and is a potent nerve agent; the World Health Organization (WHO) considers chlorpyrifos to be moderately hazardous (Class II). The use of fipronil is under review in Australia by the APVMA because of environmental concerns. A report is expected in 2020. Reviews on the use of chlorpyrifos are on-going in Europe, USA and Australia.
All synthetic products are likely to reduce the impact of natural predators and parasitoids against this moth, and can only be recommended as a last resort.
Due to the variable regulations around (de-)registration of pesticides, we are for the moment not including any specific chemical control recommendations. For further information, we recommend you visit the following resources:
EU pesticides database (http://ec.europa.eu/food/plant/pesticides/eu-pesticides-database/)
PAN pesticide database (www.pesticideinfo.org)
Your national pesticide guide