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Studies on host specificity
and preference of the Metallic Coloured Tortoise Beetle (Aspidomorpha
miliaris F.), a Medicinal insect
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Research Note - Pankaj Oudhia
© 2001,2002,2003 Pankaj Oudhia - All Rights ReservedINTRODUCTION
lpomoea carnea Jacq., locally known as Beshram, is one of the common obnoxious weeds in Chhattisgarh region (Oudhia and Tripathi, 1998a). Inhibitory allelopathic effects of this weed on germination and seedling vigour of many agricultural crops have been reported (Oudhia and Tripathi, 1998b). During 1997- 98 and 1998-99, heavy infestation of Tortoise beetle, also known as Fool's Gold beetle, was noted on lpomoea carnea and related species. The damage was caused by the adults and grubs feeding on the leaf tissues. Aspidomorpha milliaris F. (Chrysomelidae; Coleoptera) is a serious pest of sweet potato (lpomoea batata) but sweet potato is not under cultivation in Chhattisgarh region. The fact indicates that there is possibilities of utilizing this beetle as bio-agent for lpomoea and related species. Due to non-availability of any information regarding different hosts of this possible bio-agent of lpomoea in Chhattisgarh, the studies on host specificity and preference were conducted using more than 40 test plants including agricultural crops, weeds and ornamental plants.
Table - 1 Studies on host specificity and preference of the metallic coloured Tortoise beetle (Aspidomorpha miliaris E) Test Plant Species Local Name Response of Beetles Remark (+) (-) 1 Cynodon dactylon Doobi - Weed 2 Croton sparsiflorus Vanmirch - Weed 3 Calotropis gigantea Fudhar - Weed 4 Datura stramonium Dhatra - Weed 5 Sida acuta Bariyara - Weed 6 Ipomoea reniformis Muscani ++ - Weed 7 Commelina benghalensis Kauakaini Weed 8 Lantana camara Gotiphool - Weed 9 Parthenium hysterophours Gajargha - Weed 10 Citrus medica Nimbu - Fruit crop 11 Psidium guajava Jam - Fruit crop 12 Mangifera indica Aam - Fruit crop 13 Calliandra haematocephala Lal phool - Ornamental 14 Melia azedarach Bakain + - Ornamental 15 Acalypha hispida Shankarjata - Ornamental 16 Jasminum sambac Mongra - Ornamental 17 Hibiscus rosasinensis Dashmath - Ornamental 18 Saraca indica Ashok - Ornamental 19 Ipomoea aquatica2 Karmatta ++ - Weed 20 Tridax procumbens Bhengra - Weed 21 Euphoribia hirta Duddhi - Weed 22 Phyllanthus niruri Bhuinawla - Weed 23 Catharanthus roseus Sadasuhagan - Ornamental 24 Bougainvilea glabra Kagaj phool - Ornamental 25 Luffa acutangula Torai - Vegetable crop 26 Colacasia sp. Jimikand - Vegetable crop 27 Poinciana regia Gulmohar - Ornamental 28 Codiaeum variegatum Croton - Ornamental 29 Callistemon sp. Bottle-brush - Ornamental 30 Punica granatum Anar - Fruit crop 31 Ficus carica Anjeer - Fruit crop 32 Thevetia nerifolia Kaner - Ornamental 33 Rose indica Gulab - Ornamental 34 Cyperus rotundus Motha - Weed 35 Cassia tora Charota - Weed 36 Typha angustata Hatthighas Weed 37 Achyranthes aspera Chirchita - Weed 38 Eclipta alba Bhengra van - Weed 39 Polyanthus tuberosa Rajanigandha + - Ornamental 40 Jatropha curcas Ratanjot - Medicinal 41 Convolvulus arvensis3 Hirankhuri ++ - Weed 42 Vitis vinifera Angoor - Fruit crop 43 Lagerstroemia sp. Doodh mongra - Ornamental 44 Cassia alata Nakli Sanay - Ornamental 45 Impatiens balsamina Chirya phool - Ornamental 46 Ipomoea palmata4 Panchpatri ++ - Weed 47 Ipomoea carnea1 Beshram +++ - Weed +++ ---> Heavy feeding ++ ----> Medium feeding + ----> Partial feeding - ------> No feeding 12345 - Order of preference
MATERIALS AND METHODS
Host-specificity tests were carried on 47 plant species as described by Oudhia, 1997 and Ramesh, 1996.
NO-CHOICE TEST
A twig of 15-20 cm length of each test plant species was fixed in a 25 ml conical flask containing water with the help of cotton swab. Then the twig was covered with the big plastic jars. In wide-opened mouth of each plastic jar, mosquito net was fitted for aeration. Ten field collected grubs and adults starred for 24 hours were released into the plastic jars. Beetles were allowed to feed on the test plants for 3 days. Every plant species tested had three replicates and whole experiment was repeated twice.
CHOICE TEST
Plant species including lpomoea cornea, lpomoea aquatica, lpomoea palmata, Convolvulus arvensis and lpomoea reniformis were assessed in the following test. The aim of this test was to know the host preference. Sixty field collected grubs and adults were starved for 24 hours and released into big plastic jars having fresh leaves of these plant species. The experiment was repeated for 10 times. Number of beetles settled on each plant species was recorded in 15 minutes interval upto 48 hours.
RESULTS AND DISCUSSIONS
Out of 47 plant species, feeding was observed on 7 plant species. These plant species include lpomoea carnea, lpomoea reniformis, lpomoea palmata, lpomoea aquatica, Convolvulus arvensis (All species belong to Convolvulaceae family), Melia azedarach and Polyanthus tuberosa. Heavy feeding was noted in case of lpomoea cornea whereas medium feeding was noted under other related species. In natural field conditions, similar behaviour of beetle was noted. Partial feeding was noted under laboratory conditions in Polyanthus and Melia leaves but in natural field conditions, the feeding was not observed. Also when some beetles were released on these species in field conditions, they migrated to lpomoea species. All the plant species on which heavy and medium feeding was noted are weeds except lpomoea aquatica. In Chhattisgarh region, some farmers cultivate lpomoea aquatica as vegetable crop. In such situations. Tortoise beetles are considered aspest which damages the economically important parts of 1. aquatica (i.e., leaves). But in general lpomoea acfuatica is known as problematic weed. The study on host preference revealed that beetles preferred lpomoea cornea among all the other plant species. The order of its preference is given in Table 1. Negative response of Tortoise beetles towards agricultural crops like soybean, rice maize, mung, groundnut, sesamum, castor, sorghum, cotton etc. have been reported. (Ramesh, 1996). The study suggested that there is a tremendous possibilities of utilizing this beetle for eco-friendly management of not only lpomoea cornea but also other common problematic weeds like 1. aquatica, 1. reniformis, 1. palmata and convolvulus arvensis.
ACKNOWLEDGEMENTS
Author is thankful to Dr. R. S. Tripathi, Professor and Head, Department of Agronomy, IGAU, Raipur, Dr. Jayalaxmi Ganguli, Scientist and Mr. Muktavan Das, Field Assistant for their kind co-operation during this study.
REFERENCES
Oudhia, P. ( 1997). Evaluation of host specificity of Blumea leaf beetle (Chrysolina sp. nr. madrasae Jackoby). Insect Environment. 3 (3): 80.
Oudhia, P. and Tripathi, R. S. ( 1998a). Medicinal weeds of kharif crops in the plains of Chhattisgarh. Bhartiya Krishi Anusandhan Patrika. 13(1/2): 33-38.
Oudhia, P. and Tripathi, R. S. ( 1998b). Allelopathic potential of lpomoea carnea Jacq. Agril. Biol. Res. 14 (3 & 4): 1-8.
Ramesh, P. ( 1996). Host specificity of the Tortoise beetle Aspidomorpha miliaris and its possible role in the management of lpomoea cornea and lpomoea aquatica. Indian. J. Ent: 58 (2): 140-142.(Originally published in Ecol. Env. & Cons. 6(3) : 2000; pp. (357-359)