Dynamics of limited neoplastic growth on Pongamia pinnata (L.) (Fabaceae) leaf, induced by Aceria pongamiae (Acari: Eriophyidae).

BACKGROUND: Galls or the neoplastic growth on plants result from a complex type of interaction between the inducers (Acari, Insects, Microbes and Nematodes) and plants. The present study sheds light on the gall inducing habit of a highly host specific eriophyid mite, Aceria pongamiae, on the leaves of Pongamia pinnata leading to the production of abnormal pouch like outgrowths on the adaxial and abaxial surfaces of the foliage. Each leaf gall is a highly complex, irregular massive structure, and the formation of which often leads to complete destruction of leaves, especially during heavy mite infestation, and thereby adversely affecting the physiology and growth of the host plant. RESULTS: The study was carried out by making comparative observations on FE-SEM histological sections of galls representing four different growth stages categorized on the basis of difference in age groups. Apart from variations in cell metaplasia, a dramatic change was observed in the abaxial-adaxial polarity of the laminar surfaces also throughout the developmental sequence of galls, in all the four growth stages. Significant variations could be observed in the anti-oxidative potency as well as elemental composition in the all the four age groups of galls, and also revealed ATR-FTIR pattern of gall formation. CONCLUSION: Being the first attempt to unravel the mystery of gall induction by eriophyids in general and by A. pongamiae in particular, on its host plant P.pinnata, by shedding light on the structural and histological alterations taking place during leaf gall formation under the influence of the mite, the current study is to be treated as the model of plant-animal interactive system.

Macroinvertebrate colonization and breakdown of leaves in an astatic pond in south India.

Macroinvertebrate colonization and breakdown of Pongamia pinnata and Morinda tinctoria leaves were studied in an astatic pond in Madura College, Madurai. Morinda tinctoria leaves broke down fasterthan the leaves of P. pinnata. Breakdown capacities of astatic pond cannot be attributed to colonization of macroinvertebrates. Instead, microbial processing, and abiotic fragmentation are suggested as factors controlling breakdown rates. Tanypus sp (midgelarva) was abundant in leaf bags during the experimental period. This midge-larva appeared to use litter accumulations as a microhabitat that provided shelter and a rich supply of food in the form of organic matter Their abundance and regular occurrence of two leaves suggest that midge larvae enhance leaf fragmentation and possibly mediate the incorporation of organic matter in pond sediments once the plant tissue is sufficiently macerated.

The first record of the genus Tanaostigma (Hymenoptera: Tanaostigmatidae) in the Old World, with the description of a new species from India.

Tanaostigma Howard (Hymenoptera: Tanaostigmatidae) is recorded for the first time in the fauna of the Old World, with T. indica Gupta sp. n.  described and illustrated from southern India, reared from Millettia (=Pongamia) pinnata (Fabaceae).

Epipsylla millettiae sp. nov. (Hemiptera: Psylloidea), a new psyllid from China associated with Millettia pachyloba (Fabaceae) with comments on Epipsylla including the redescription of E. hainanana.

The small genus Epipsylla is diagnosed (adults and immatures), a checklist is given for its constituent species and the phylogenetic relationships of the genus are briefly discussed. E. millettiae sp. nov., associated with Millettia pachyloba from South China is described, diagnosed and illustrated. It differs from other described Epipsylla species in the very narrow paramere. E. hainanana Yang & Li is redescribed, and additional details are provided of the male and female terminalia. Following new synonymies are proposed: Epipsylla guangxiana Yang & Li, 1983, = E. whitfordiodendritis Yang & Li, 1983, syn. nov. and Epipsylla mucunae Yang & Li, 1984, = E. ruiliana Yang & Li, 1984, syn. nov., E. yunnanica Yang & Li, 1984, syn. nov.