Diversity and population dynamics of thrips species on horticultural crops in Punjab

Thrips fauna of Punjab have been poorly studied despite their significance on fruit and ornamental plants. Surveys and surveillances were, therefore, carried out in the six agro-ecological zones of the Indian Punjab since 2004, to study the biodiversity of thrips species on fruit crops and ornamental plants. During these surveys, 12 species of thrips viz., Frankliniella schultzei (Trybom), Haplothrips ganglbaueri Schmutz, Haplothrips sp., Megalurothrips distalis (Karny), Rhipiphorothrips cruentatus Hood, Rhipiphorothrips pulchellus Morgan, Rhipiphorothrips sp., Scirtothrips bispinosus (Bagnall), Scirthothrips dorsalis Hood, Thrips florum Schmutz, Thrips hawaiiensis (Morgan) and Thrips palmi Karny have been recorded in Punjab. Out of these, F. schultzei, M. distalis, R. pulchellus, S. bispinosus and T. hawaiiensis have been recorded for the first time from Punjab. Among fruit crops, Eriobotrya japonica (Thunb) Lindl., Malus sp., Psidium guajava L., Punica granatum L., Pyrus communis L., Syzygium cumini (L.) Skeels. and Vitis vinifera L. have been reported as new host plants for H. ganglbaueri, M. distalis and T. florum, S. bispinosus, Rhipiphorothrips sp., Rhipiphorothrips sp., S. dorsalis., R. cruentatus and R. pulchellus and R. cruentatus and Haplothrips sp., respectively. Mansoa alliacea Gentry., Polianthes tuberosa L., Rosa indica L., Tabernaemontana spp., and Tagetes sp. are here reported as new ornamental host plants to T. florum and T. palmi, F. schultzei, T. palmi, S. dorsalis and T. florum, respectively. Diagnostic features, distribution and host plant data for all the recorded species are given. The number of known species of thrips in Punjab is thus increased to fifty one. The population of thrips on different plant parts in fruit crops ranged from 75.3 to 210.6 in citrus, 40.8 to 78.3 in guava, 25.3 to 40.3 in mango, 80.4 in pear, 80.3 to 100.3 in grapes, 42.3 to 200.3 in pomegranate, 80.4 to 215.6 in loquat, 573.3 in jamun and 76.4 in apple. Among ornamental plants, the population ranged from 105.6 to 280.3 in rose, 1083.4 in marigold, 250.3 in tuberose, 325.3 in garlic creeper, 654.3 in single chandni and 780.3 in double chandni. The percent damage caused by the thrips on different plant parts in fruit crops ranged from 15.3 to 70 % in citrus, 2.7 to 5.3 % in guava, 2.0 to 3.5 % in mango, 3.5 % in pear, 10.3 to 15.6 % in grapes, 2.3 to 5.7 % in pomegranate, 5.6 to 10.3 % in loquat, 3.4 % in jamun and 5 % in apple. Among ornamental plants, the per cent damage ranged from 3.4 to 5.3 % in rose, 15.3 % in marigold, 5.3 % in tuberose, 10.3 % in garlic creeper, 15.4 % in single chandni and 18.3 % in double chandni.