Insect Pests of Vegetable, Tuber and Spice Crops

Exercise: 13 & 14

Exercise: IDENTIFICATION OF INSECT PESTS AND THEIR DAMAGE SYMPTOMS IN SPICES CROPS

INSECT PESTS OF CARDAMOM
1. Banana aphid, Pentalonia nigronervosa (Aphididae: Hemiptera):

• Damage: Both nymphs and adults suck the cell sap from leaf sheath and pseudo stem. The damage caused by direct feeding is little but the pest is of considerable significance being vector of cardamom mosaic (Kattle disease), Amomum mosaic and foorky disease of large cardamom. The aphids are disseminated in cardamom plantation mostly by crawling from plant by the contact of foliage at the tip and along the soil.
• Wingless aphid is dark brown pyriform measuring on an average 1.34 mm in length. Abdomen is dark brown, shining and slightly bulged. The winged form is dark brown elongated and pyriform. They are larger than the wingless with less body width.

2. Cardamom thrips, Sciothrips cardamomi (Thripidae: Thysanoptera):

• This insect is a serious pest of cardamom. It lacerates all aerial parts and feed on oozing sap. Infestation on panicle and flower buds results in stunted growth of panicles, shedding of flower buds and warty growth on the surviving capsules. The infested capsules are light in weight, inferior in quality and fetch very low price in the market. Pest population is high during dry months i.e. December in April.

3. White fly, Dialeurodes cardamom (Aleyrodidae: Hemiptera):

• This whitefly has become a serious threat causing extensive damage to cardamom plants. Damage is caused by the nymphs and adults by sucking the cell sap from leaves. Infested leaves turn yellow. Attack first appear on the lower leaves and gradually progresses to the cupper region. High population of the pest cause extensive damage to foliage which leads to drying up of the whole plant.
• Newly emerged nymphs which are green in colour, crawl for few hours and after finding a suitable place settle down and feed in situ.

Insect pests of large cardamom

• Hairy caterpillars, Clelea plumbisla
• Stem borer, Glyphipteria sp.
• Betles, Chrysomela chlorine
• Cerogria quadrimacuta
• White grubs

4. Castor capsule borer, Dichocrosis punctiferalis (Pyralidae: Lepidoptera):

• The castor capsule borer is a serious pest of nursery plants and young green pods of cardamom. In nursery plants it bores into the stem and cause death of the central shoot. It also eats away the tender seeds of young berries.
• Larvae are reddish brown with black blatches all over the body and a pale stripe on the lateral side.

5. Cardamom hairy caterpillars:

• Lenodera vittata (Lesiocampidae lepidoptera):
• They hairy caterpillars are commonly found feedings on cardamom in South India. The moth is stout, fairly big and densely covered with scales. The larvae are clothed with a dense belt of capitate hairs and measure about 106-110 mm in length.
• Eupterrote cardamomi (Eupterotidae: Lepidoptera)
• It is a sporadic pest of cardamom in South India. The adults are large moths, ocherous in colour, with post medial lines on the wings. They measure 70-80 mm in wing expanse. The larvae are hairy, dark grey in colour with pale brown head, bearing conical tuft of hairs on the dorsal side of the body. When full grown the caterpillar measures 90 mm in length.
  
• The larvae feed on leaves of the shade trees up to the 6th or 7th instar and then they drop down to the cardamom plants growing underneath with the help of silken threads. They start feedings on the leaves voraciously and defoliate the cardamom plants causing heavy reduction in the yield.

• Other hairy caterpillars:
• Eupterote canarica
• E. testacea
• E. fabia

• These hairy caterpillars are sporadic and occasionally cause damage to cardamom plants. The life cycle and habits are similar to above described species.

6. Rhizome weevil, Prodioctes haematicus (Curculionidae: Coleoptera):

• The rhizome weevil is found widely on cardamom plants in different states of south India. The adult is a brown weevil measuring 12 mm in length. Damage is caused by grubs by tunneling and feeding inside the rhizomes resulting in death of entire plumps of the cardamom plants.