eChapters

1.0 INTRODUCTION

Among tree spices, nutmeg (Myristica fragrans Houtt) belonging to the family Myristicaceae is the most important, providing two spices, i.e. the nutmeg (dried seed) and the mace (dried aril covering the seed). The latter is more important. Nutmeg is cultivated mostly in the tropical areas of Indonesia and West Indies. The world annual production of nutmeg and mace is around 12000 tonnes and 2000 tonnes, respectively (Krishnamoorthy and Rema, 2001). A native of the Moluccas (The Banda Islands of East Indonesia), nutmeg is presently cultivated in several countries such as Grenada, Malaysia, Papua New Guinea, Sri Lanka, Fiji, some Caribbean Islands, Africa and China including India. Of late, Brazil also started its cultivation. The Indonesian nutmeg known as East Indian nutmeg shares 75% and Grenadian known as West Indian nutmeg shares 25% of world market and they are major suppliers in the world. The East Indian nutmeg is highly aromatic which is preferred by the USA. West Indian type is of mild flavour and is preferred in Europe. The major importers are USA, Canada, Japan and European countries. In USA, the oil is generally preferred whereas the Europeans consume it as whole spice.

1.0 INTRODUCTION

Vanilla is one of the most popular and widely used flavour materials in the world and it is the most expensive spice traded in the global market after Saffron (Crocus sativus L). The major consumers of vanilla beans currently are the developed countries with the US, France and Germany absorbing about 80 per cent of the world imports. Among them, the US imports 50-60 per cent while the latter 10-15 per cent each. They are also main re-exporters of both vanilla beans and processed products. The total area under vanilla cultivation in the world during 2002 was 38,066 ha with the production of around 4956 metric tones and increased to 76,440 ha with a production of 10, 360 tons during 2005 (FAO, 2007). The major vanilla producing countries are Madagascar, Comoros, Indonesia, Mexico and Reunion (Table 1). Area under vanilla in India during 2002-03 was 2545 ha with the production of 92 tonnes. (Spices Board, 2003) and increased to 5370 ha with a production of 196 tonnes during 2004-05.

1.0 INTRODUCTION

Turmeric (Curcuma domestica Val. (syn. C. longa Koenig non L.) is an important spice, a native of India and South East Asia. Chikarmane et al. (2003) by analyzing historical patterns of movement of South Asian and Southeast Asian people known to have used turmeric suggested that turmeric was introduced into Southeast Asia via Indian colonization in the early Christian centuries. An increase in colonization events from South India during this time was because of discoveries in navigational science and desires to expand civilizations, rather than military conquests. The cultural expansion from South India supports the introduction of turmeric cultivation to Southeast Asia via human means. These human migratory patterns are compared to a phylogenetic analysis of DNA sequence data within Curcuma, and suggested that key locations such as the Isthmus of Kra were important not only to human movement but to species evolution in Curcuma (Chikarmane et al., 2003).

1. INTRODUCTION

Ginger (Zingiber officinale Rosc.) is a perennial herb and the economic part is underground stem (rhizome), which is used as a spice. It is native to tropical South-East Asia, introduced into the West Indies, African countries and other tropical belt of the world. The ginger rhizome is harvested between 6 and 12 months after planting and used as spice in the fresh condition,  peeled and split dried or powedered forms. Ginger is utilized widely as a spice, for pickles, candies and as a medicinal herb. The anti-inflammatory and anti-nausea qualities of ginger have applications in the pharmaceutical industry. Ginger and supplements derived from ginger have received attention for the treatment of chronic inflammation. Administration of ginger has resulted in decreased symptoms of rheumatoid arthritis (Srivastava and Mustafa, 1992) and gingerol (a component of ginger) has been reported to have anti-inflammatory actions (Kiuchi et al., 1992; Tjendraputra et al., 2001).

1.0 INTRODUCTION

Plant parasitic nematodes are among the major soil-borne crop pests that cause significant economic losses to a wide variety of crops. They cause an estimated annual crop-yield loss of US$78 billion worldwide which warrants for effective control strategies (Sasser and Freckman, 1987). Nematodes have the greatest impact on crop productivity when they attack the roots of seedlings or young plantlets (Ploeg, 2001). Nematode feeding also creates open wounds that provide entry to a wide variety of plant-pathogenic fungi and bacteria. These microbial infections are often more economically damaging than the direct effects of nematode feeding.

1.0 INTRODUCTION

Cardamom (Elettaria cardamomum Maton.) acclaimed as the ‘Queen of Spices’ is the true cardamom belonging to the family Zingiberaceae. The cardamom of commerce is the dried ripe fruit and is one of the most important valued spices next only to saffron. It is native of evergreen forests of Western Ghats of South India. Cardamom is a shade loving plant (Pseophyte) thriving well in elevations up to 600-1200 m above MSL under an average annual rainfall of 1500-4000 mm and temperature range of 10-350C. India has been the world’s largest producer of cardamom until 1979-80. Later, Guatemala emerged as world’s premier producer and the exporter of cardamom accounting for about 90 per cent of the global trade. Cardamom is also grown lesser extent in Sri Lanka, Papua New Guinea and Tanzania.

1.0 INTRODUCTION

Black pepper popularly known as ‘King of spices’ or ‘Black gold’ is one of the important and earliest known spices produced and exported from India. Its original home is the dense evergreen forests of Western Ghats in south India. The flavour and fragrance of this oriental spice had a magic spell in human civilization and culture since very ancient days. Expeditions in search of pepper led to the discovery of new trade routes.

1.0 INTRODUCTION

The bacteria in the genus Ralstonia, Xanthomonas, Agrobacterium, Xylella, Pantoea, Leifsonia, Curtobacterium, Enterobactor, Pseudomonas, Corynebacterium, Erwinia cause the most important bacterial diseases of crop plants. Few of them are directly responsible for post harvests losses during storage or transit and many of them are known to cause disease in the field. These diseases are economically important due their potential to cause crop failure in crops including spice crops. Among the bacteria genus Ralstonia is very important owing to its broad host range across the plant kingdom. Traditionally bacterial diseases of crops are prevented by the principle of ‘Disease Avoidance’ rather than disease control in the field. Their fast rate of multiplication, selective host and rapid spread in the field makes the disease control one of the challenges in the production system. The organic strategies are very well fit in the disease avoidance in the field. The preemptive strategies works exceedingly well for management of bacterial disease in any crop. Few genus such as Ralstonia, Enterobacter and Xanthomonas have been frequented in spice crops.

1.0 INTRODUCTION

“Biological control is the reduction of the amount of inoculum or disease producing activity of a pathogen  or parasite  in its active or dormant state, by one or more organisms, accomplished naturally or through manipulation of the environment, host or antagonist or by mass introduction of one or more antagonists ” (Baker & Cook 1974). The biological world is a vast interacting network of living organisms in a state of dynamic equilibrium, reflecting changes in their physical environment and their relations to each other. Organisms exhibit many type of interactions in the process of achieving biological balance.  An organism may exert no effect on another or it may stimulate or inhibit the growth or development of the associate, it may stimulate or inhibit the formation of resting spores of the associate or it may enforce dormancy or cause lysis of the associate (Cooke & Baker, 1983).

1.0 INTRODUCTION

Infestation by insect pests is a major factor responsible for the low productivity of spice crops in India. Spice crops such as black pepper (Piper nigrum L.), cardamom (Elettaria cardamomum Maton), ginger (Zingiber officinale Roscoe) and turmeric (Curcuma longa L.) are infested by many species of insect pests, some of which cause severe crop losses. Adoption of integrated pest management (IPM) schedules in which biological control forms a major component is more relevant in these crops since excessive use of insecticides could lead to pesticide residues in the produce and other ecological hazards. Spices are high-value and export-oriented in nature and pesticide residues are the most important non-tariff barriers on trade in these produces. There has been a renewed interest during the past decade in developing environment–friendly crop management schedules in sustainable agriculture including spice crops, reflecting the increasing concern over pesticide misuse.

1.0. INTRODUCTION

The plant nutrient cycling depends on micro organisms that constitute major components of the biosphere. Although less than one per cent is cultured, a tremendous diversity exists in their populations. Transformation of nutrients from soil to plants is brought about by soil microorganisms. Latest molecular techniques enable scientists to understand and appreciate the diversity and help to utilize the beneficial effects of microbial diversity for increased productivity. Among soil organisms intense activity is found in and around rhizosphere of plants because of the presence of the secreted nutrients such as carbohydrates, amino acids and other cellular components present at the growing tip of roots. These root colonizing micro organism form symbiotic, associative, or parasitic relationship with the plants. These organisms have evolved mechanisms to occupy and reside in the specialized niche. These mechanisms are often utilized both for growth enhancement and disease suppression. The host also plays an important role in selecting its own microflora for the rhizosphere similar to the probiotic microflora of human gastrointestinal tract (Haas and Keel 2003).

1.0 INTRODUCTION

Soil fertility can be considered to be a measure of the soil’s ability to sustain satisfactory crop growth, both in the short and longer-term. Organic farming recognizes the soil as being central to a sustainable farming system. It could be argued that organically managed soils require a higher level of baseline fertility because shortfalls cannot be made up by applications of soluble fertilizers. Soil fertility is determined by a set of interactions between the physical and chemical environments of the system and by biological activity. Organic matter is linked intrinsically to soil fertility, because it is important in maintaining good soil physical conditions (e.g. soil structure, aeration and water holding capacity) and is an important nutrient reserve. Organic matter contains most of the soil reserve of N and large proportions of other nutrients such as phosphorus and sulphur.

1.1 Spice – definition and uses

Spice is defined as “a strongly flavoured or aromatic substance of vegetable origin, obtained from tropical plants, commonly used as a condiment”. A spice is a dried seed, fruit, root, rhizome, bark or vegetative substance or flower bud used in nutritionally insignificant quantities as a food additive for the purpose of flavoring. Spices are distinguished from herbs, which are leafy, green plant parts used for flavoring purposes. Herbs, such as basil or oregano, may be used fresh, and are commonly chopped into smaller pieces; spices, however, are dried and usually ground into a powder (http://www.reference.com/browse/wiki/Spice). American Spice Trade Association (ASTA) defines spices as “any dried plant product used primarily for seasoning purposes”. Included are tropical aromatics (pepper, cinnamon, cloves, etc.), leafy herbs (basil, oregano, marjoram, etc.), spice seeds (sesame, poppy, mustard, etc.) and dehydrated vegetables (onions, garlic, etc.) (http://www.astaspice.org/spice/frame_spice.htm). Many spices have other uses like food preservation, medicine, religious rituals, cosmetics, and perfumery or as vegetables.

Reducing insecticide application to the lowest level is the motto of IPM in vegetables. Monitoring for the initial build up and timely mechanical removal of the first population is a must in vegetables. Always remove the first affected plants, by diseases like mosaic, and destroy them by burying or burning. Remove insect eggs, insect affected plant parts and adults and immature stages of insects, and destroy them every day. Do not throw them in the field. They will either come back, or pupate and attack later. During nursery stage, use wood ash, cow dung solution, and plant extracts to deter all pests. Use only low residual insecticides like Dichlorvos 1ml/l, Malathion 2ml/l, Endosulfan 2ml/l or Quinalphos 2ml/l, in spots, at the beginning of attack itself.

Fruit borer: Helicoverpa armigera: Noctuidae

This is a medium sized moth yellowish brown in colour with a wing

span of about 3 cm and a body length up to 1.4 cm. There is a dark speck and a dark area on the outer margin of each forewing. The forewings also have greyish wavy lines and black spots of different sizes on the upper side.

Sciarid(mushroom flies): Bradysia paupera, Lycoriella auripila: Sciaridae

The larvae feed on the mycelial attachments and restrict the growth of the spawn. The maggots also feed on the developing mushrooms or pinheads and thus cause loss in yield. They also bore the developing mushrooms and render them hollow.

Fruit flies: Bactrocera cucurbitae:Tephritidae

This pest is more serious in bitter gourd, snake gourd and to a certain extent on ridge gourd. Other cucurbits are attacked to a lesser level. Damage by this pest causes losing the fruit quality, rotting and fruit drop. The adults lay many eggs inside the fruit sing their big ovipositor that hatch out into worm like apodous maggots. Feeding by the maggots on the pulp of fruits result in rotting, yellowing and fruit drop. The dropped fruits allow pupation by the maggots in the soil from where they emerge out as adults and start egg laying on fresh frits.

The cowpea aphid: Aphis craccivora: Aphididae

Hosts
 
Groundnut, red gram, peas, beans, safflower, lab-lab niger

Symptoms of damage
 
Both nymphs and adults cause the damage by sucking the plant sap from shoot tips, pods and leaves.  Infested pods become malformed and withered.  Severe infestation may result in complete drying of affected pods.  They also act as vector of virus diseases in pea. 

Chilli thrips: Scirtothrips dorsalis, Thrips palmi: Thripidae

The adults of this insect are small brownish black with fringed wings. The nymphs are slender and yellowish straw coloured, later acquiring more brownish hue. They lacerate the tissues and feed on the exuding sap. Leaves become crinkled, curled upward and shed. The attack can be confused with chilli mosaic symptom.  In capsicum and chilli, they also feed beneath calyx of flowers and fruits causing flower/fruit drop and reduction in yield and market value of capsicum. Buds become brittle and drop down. Plants get stunted and bronzed. The fruits if at all formed are crinkled and small.

Diamond back moth: Plutella xylostella: Plutellidae
 
The adults of this moth are small, greyish brown having pale whitish narrow wings and with inner margins yellow. There are three pale whitish triangular markings on hind margins of each forewing. At rest, when both forewings come together, they form a dorsal median patch of three diamond shaped yellowish white spots that give them their name diamond back moth. Hind wings have a fringe of long hairs.

Shoot and fruit borer: Leucinodes orbonalis: Pyraustidae

The pest is active throughout year, but more during monsoon period. Heavy losses up to 60% can occur.

The adult is a greyish brown medium sized moth with white and hyaline wings, having triangular brown and red markings on forewing. A crescent shaped mark facing outside at the apical margin is typical for the species. About 150-250 creamy white eggs are laid singly on leaves, tender shoots, flowers and developing fruits. Egg period is 3-5 days and the hatched larva completes its life in 15 days with 5 instars.

Shoot and fruit borer: Earias vitella (=E.fabia), E. insulana: Noctuidae

This is a pest on cotton, bhendi, hibiscus, holly hock and other malvaceous vegetables. The damage is due to the larva that bores into tender terminal shoots in the vegetative stage and flower buds;  flowers and young fruits in the fruit formation stage.  The damaged shoot drops, wither and dry up.  The infested fruits have bore holes, are deformed and become unfit for consumption.  Bore holes are plugged with excreta.

Amaranthus stem weevil: Hypolixus truncatulus :Curculionidae
 
It is an important pest of amaranthus and is widely distributed in India. It attacks both wild and cultivated amaranthus, especially the leafy varieties with large leaves. Hence, management involves destruction of unwanted, weedy wild amaranthus plants, to reduce the breeding place for the weevil. Adults are ash-grey in colour, with elbowed antennae and brown elytra. Females lay eggs singly in holes made on the stem, branches, petioles or midribs. Eggs are smooth, oval and pale yellow in colour. Incubation period is 3 to 8 days.

Sweet potato weevil: Cylas formicarius: Apionidae

It is a specific pest of sweet potato and the most important one. Adult weevils are ant-like, slender bodied having elongated snout-like bluish-brown head with geniculate antenna, bright red thorax and leg tips and bluish-brown elytra. Females make small cavities on the tubers or stems and lay eggs singly. Each female lays 180-200 eggs. Grubs are elongate, legless, pale-yellowish white in colour with smaller brown head. Pupation takes place in larval tunnels in the tuber. Incubation, grub and pupal stages last for 5 to 8, 14 to 17 and 4 to 5 days respectively. Life cycle is completed in 4-5 weeks and adults live for 95-110 days. The grubs bore into stems, tunnel inside and feed on soft tissues. Grubs and adults bore into tubers both in field and storage godowns. Affected tubers develop dark patches, which later start rotting. Feeding holes and adult emergence holes can be seen on vines and tubers.  In severe infestation the collar region of the plants shows unusual thickening due to proliferation and hypertrophy of tissues causing a characteristic terpenoid odour.  Even the slightly damaged tubers are unsuitable for cooking and consumption.  Hence yield loss in practice may come to 100% in many cases.

Aphids: Myzus persicae, Lipaphis erysimi and Brevicoryne brassicae Aphididae
 
Aphids suck the sap from potato foliage, causing wrinkling, cupping and downward curling of young leaves. The older leaves will become yellow, wilt and fall off.  They also excrete honeydew on which sooty mould develops covering affected parts with a thin superficial black coating that hinders photosynthetic activity of leaves resulting in stunted growth of plants. In addition, they also act as vectors, for transmitting potato leaf roll virus. Major damage by M.persicae and A. gossypii is through transmission of potato leaf roll virus.

Leaf-and shoot folders: Hymenia recurvalis : Pyraustidae

Pycnarmon cribrata;Phostria piasusalis

Cassava scale : Aonidomytilus albus: Diaspididae

White elongated scales appear in colonies on stems. Plants die in the field and under storage.  Stem becomes weak and dry, causing side branching to give bushy appearance.  Viability of planting material is reduced, resulting in poor establishment.

Aphids: Aphis gossypii :Aphididae

The aphids congregate on growing points and suck the sap. Honey dew secreted by the aphids can cause sooty mould in severe infestation. Attack leads to yellowish speckling and curling of leaves.
 
Thrips: Caliothrips indicus: Thripidae

Characteristic silvery white specks with black dots which are mostly faecal pellets, develop on leaves. Consequently, the leaves dry up.

Pollu beetle: Longitarsus nigripennis:Chrysomelidae

This pest is monophagous to pepper and no alternate host has been reported so far.

Nature of Damage

Adult is a shining blue flea beetle with yellow head and thorax and has thick enlarged femur and tibia. The adult beetle is only the size of a pin head.  The infested berries dry up and turn dark in colour. Berries become hollow and crumble when pressed and such hollow berries are called “Pollu” meaning empty. The eggs are laid on the berries @ 1-2 eggs in each hole. Eggs hatch in 5-8 days. The grub period extends for 30-32 days. The emerging grubs feed on the berries of pepper and consume the internal contents.

Thrips: Thrips tabaci: Thripidae

The nymphs and adults of the thrips desap from the narrow spaces between the inner leaf axils. Leaves are faded, with curled tips and shining silver streaks or brown spots.  Many minute yellow or white insects are seen moving, generally near the base or middle of leaves and they suck the sap from the plants.  Plants are faded and the yield is reduced.

Scale insects:Pseudaulacaspis cockerelli, Parasaisettia nigra:Coccidae

Attack Adults and nymphs feed on plant sap and cause wilting and drying of seedlings and young plants.
 
Brown soft scale: Lecanium sp. (=Coccus) hesperidum : Coccidae

Grasshoppers: Mecopoda elongata :Tettigonidae; Oxya velox: Acrididae

These pests occur both in nurseries and plantations. Both adults and nymphs feed on leaves by scrapping and eating outer tissues and margins. The emerging leaves are nibbled and the spot holes appear when the leaf unfurls. In severe conditions the entire leaf is eaten leaving behind only the midrib.

Shoot borer: Conogethes punctiferalis: Pyraustidae

The main damage done by the caterpillar of this pest is to bore holes in the pseudostem and to plug it with excreta, causing dead hearts. Larva is pale greenish with pinkish tinge and dark head and has fine hairs on the body with a pro thoracic shield. Adult is a medium sized moth, pale yellowish with small black spots on the fore and hind wings.

Management involves spraying dimethoate or malathion 1.5 ml/lit or phosphamidon 0.75 ml/lit of water. This is mainly intended to manage the adults flying in the crop canopy and the first instar caterpillars that are seen on the outside of the plants and before thsy enter the pseudostem. The spray has to be given at the very first spotting of dead haearts.

Coriander aphid: Hyadaphis coriandri: Aphididae

Coriander aphids are yellow-green in color, dusted with grayish wax. They have short, dusky, slightly swollen, siphunculi (or cornicles). The Aphids form dense, damaging colonies on leaves, heads, and stems of their host plants.

In its native land, Florida, USA, the life cycle of the coriander aphid is similar to that of other host-alternating aphids. Overwintering eggs occur on other hosts.  A fundatrix (or stem mother) hatches from the egg in the spring. Her offspring are parthenogenetic, and the winged-females are spring migrants. They colonize summer host plants in the family Umbelliferae.

Stem-borer: Sahyadrassus malabaricus: Hepialidae

Presence of the pest is understood when chewed tissue is seen at at the col­lar region. The mouth of the tunnel in which the borer feeds show pieces of bark, wood and frass particles held together by silk. The saplings break off at the point of injury. When the main stem is attacked, there is mat-like frass at basal region of stem. Larvae girdle main stem and bores downward killing the tree.

Adult moth is peculiar and hangs vertically down by the support of two pairs of legs. Egg period is for 7-10 days, and larvae live for about 10 months inside the larval tunnels. They pupate for 3-5 weeks.

Cinnamon butterfly: Chilasa clytia clytia : Papilionidae

Larvae defoliate plants. The larvae are pests on many crop plants and weeds and are common in the plains. The larvae are jet black at hatching. They develop a series of broad white patches. The adult is a common butterfly rich velvety brown, and spotted with white dots. The hind wings have arrow shaped streaks and crescent shaped spots.

Cardamom thrips: Sciothrips cardamomi: Thripidae

Thysanoptera

This thrips attacks other crops like amomum,  tea, colocasia, grapevine, castor, cotton, ginger and turmeric also. The thrips are minute greyish brown insects with fringed wings. They breed on unopened leaves, spindles, leaf sheath, flower bracts and floral tubes .

Scale insect: Lepidosaphes sp.: Diaspididae

The mature scale is elongated and oval in shape and dark grey in colour. They infest the stems, leaves and petioles, causing shriveled leaves due to sucking of the sap. The affected parts wither and dry up. In severe infestation leaves dry up and give sticky look and gradually the vine wilts.

Tea tortrix/flushworm: Homona coffearia:Tortricidae

The tortrix is  an important pest of tea leaves. The larvae make leaf nests by webbing the leaves using silken threads and feed from inside. A single caterpillar makes several cases. Young larvae prefer tender leaves, while the older larvae are seen in mature leaves. The economic produce being the leaves, and since chemical control is not advised, especially during the picking phase, the pest becomes a management problem.

Spindle bug: Carvalhoia arecae :Miridae

Nymphs and adult bugs suck the plant sap from spindle leaf and tender leaves.  Feeding marks are seen as necrotic lesions in the spindle and fully opened leaves.  The pest is seen in the nursery plants round the year but incidence is high during rainy season.

Coffee is an important cash and export crop for small-scale farmers. The crop suffers heavy yield losses due to damage caused by a wide range of insect pests
 
White stem-borer : Xylotrechus quadripes : Cerambycidae

This is one of the important and serious pests of arabica coffee. Other types are also attacked to a slightly lesser extent. The adult is a dark-brown longicorn beetle having several white markings on the elytra and thorax.

Though the coconut palm is subjected to attack by a number of insect and non insect pests although only 8-10 species of insect pests are considered to be important. Others assume importance, once in a while at isolated locations.

Major pests

The major pests of coconut include the rhinoceros beetle, red palm weevil, black headed caterpillar, root grub and the perianth mite.

Cacao Mealy Bug : Planococcus lilacinus : Pseudococcidae

The adult female mealy bug is 3.9 mm in length and 2.25 mm in width. Eggs are laid on the plant parts within a mass of tangled waxy strands, a female laying 50 to 300 eggs. The eggs hatch in less than 6 hours and the nymphs feeding on the plant juice become full-grown in 20-25 days with a mean of 23 days in the case of females and 17 to 20 days for the males. The male nymph assumes a pupal period which lasts for 4 to 6 days and the adult male is winged. They live for 2-3 days while the adult female has longevity of 12 -16 days. The females dominate the population, 67.6 per cent of the crawlers developing into female mealy bugs.

The Tea mosquito bug : Helopeltis antonii : Miridae

The host range of this bug also includes tea, neem, moringa and guava. The attack can cause inflorescence blight, terminal drying of young shoots and heavy yield loss. The adult is a reddish brown bug with black head, red thorax, and black and white abdomen. The easiest identifying character for this pest is a pin like process on the scutellum mid dorsally on the thorax. It is reddish brown, erect and knobbed, and would seem as a pin inserted into the scutellum.

Spindle bug: Carvalhoia arecae :Miridae

Spindle bug is a serious pest multiplying rapidly with the close of monsoon. The adults are red and black and nymphs are greenish in colour with reddish brown patches. Both these stages colonize the top-most leaf axils at the base of the spindle. Adults and nymphs suck the sap from emerging spindle, tender leaves and other tender parts. For feeding they move out and later return to the axils again. At the site of feeding a longitudinal narrow, decolourised zone develops rapidly on either side of the puncture, along the length of the leaf blade. The decolourised patch gradually turns yellowish, then brownish, become stunted, twisted and malformed in a few days and dries up. In this way the tissues may break away and drop off in the wind leaving shot holes on the leaves. In cases of severe infestation the leaves get shred, stand erect and the palms become stunted.

Thrips: Thrips tabaci : Tuberose thrips Franklinella schultzei: Thripidae

These minute insects, preferring hot humid weather, rasp and suck the cell sap, causing bronzing, withering and drying up of leaves and flowers. This is the most serious pest on tuberose. Damage to young plants results in stunted growth.

Hard Red scale: Aonidiella aurantii :Diaspididae

Both adults and young scales suck the sap from the stem and cause spot yellowing and loss of vigour of the plant. Infested shoots bear reddish brown encrustations of the scale and in case of severe damage the shoots dry up.

Biosduval Scale/Orchid scale : Diaspis boisduvalii : Diaspididae

These scales are round flat and yellow in colour. Only the first instar crawlers move. The others are sedentary. The young and mature scales suck the juice from the leaves, petioles and shoots and also inject toxins into the plant. Affected plants turn yellow in patches, lose vigour and get stunted.

Bud caterpillars : Helicoverpa armigera : Noctuidae

Eggs are laid singly on young buds.  Larvae feed on developing flowers by damaging florets. They can also eat the leaves.

Leaf webber : Phycita sp. : Phycitidae

Larvae of Phycita sp. feed on heads of buds and flowers.

Bud-worm : Hendecasis duplifascialis : Pyraustidae

This pest is serious on J.sambac. The larvae are dark green with black head which bores into immature buds.  They make a hole on the buds, and feed inside, leaving behind faecal pellets entangled in few silk strands. Webbing is seen in severe infestation and pupation takes place in soil.