The role of some cyclorrhaphan flies as carriers of human helminths in Malaysia

The role of some adult flies (Diptera: Cyclorrhapha) as carriers of helminth parasites of man was studied at four sites in Malaysia: a refuse dump, where no helminth-positive flies were detected, and in three peri-domestic situations where four species of flies carried up to three types of nematodes. The dominant fly species Chrysomya megacephala (Fabricius) carried eggs of the roundworm Ascaris lumbricoides L., the pinworm Trichuris trichiura (L.) and hookworm on the adult external body surface and in the gut lumen, in association with Bukit Lanjan aborigines. Chrysomya rufifacies (Macquart) and Sarcophaga spp. also had Ascaris lumbricoides and Trichurus trichiura eggs in their gut contents. Human helminths were not recovered from Lispe leucospila (Wiedemann), Lucilia cuprina (Wiedemann) or the housefly Musca domestica L. In an urban slum area of Kuala Lumpur city, filariform larvae identified as the hookworm Necator americanus (Stiles) occurred in the intestines of the face-fly Musca sorbens Wiedemann (22 larvae per 100 flies) and of Chrysomya megacephala (4.5 larvae per 100 flies). This concentration of apparently infective N. americanus in M. sorbens, a fly which often breeds in faeces and browses on human skin, could have transmission potential.     

Transfusion Tissue in the Leaves of Thuja orientalis L.

The studies on the development and structure of transfusiontissue in the leaves of Thuja orientalis L. reveal that thetransfusion tissue develops all around the vascular bundle andforms a broad wing-like structure on either side of the midrib,in almost the entire length of the leaf. It extends beyond thevascular strand and reaches the apex where it is reduced considerably. The transfusion tissue in T. orientalis is of complex natureand is composed of living and non-living elements. The formerincludes transfusion parenchyma and albuminous cells while thelatter only the tracheids. Both vary in their size and shapeat various positions within a leaf.     

Relative Sensitivity and Tolerance of some Gladiolus Cultivars to Sulphur Dioxide

Five Gladiolus cultivars, namely ‘Aldebaran’, ‘BrightEye’, ‘Illusion’, ‘Manisha’ and‘Manmohan’, were exposed to 1 and 2 µg l^–1sulphur dioxide to test their relative-sensitivity toleranceto the pollutant Plants were fumigated experimentally for 2h daily Foliar injury symptoms were observed first in ‘Manisha’followed by ‘Aldebaran’ and ‘Illusion’at the higher dose Photosynthetic pigments and leaf extractpH were significantly decreased, particularly in ‘Manisha’and ‘Illusion’ Overall disturbances in the plantmetabolism due to SO₂ treatment led to retarded growth of plants,as evident from decreased shoot length and phytomass valuesThe order of sensitivity of the five Gladiolus cultivars toSO₂ was as follows, with the greatest first Manisha, Illusion,Aldebaran, Bright Eye, Manmohan Cultivars, Gladiolus, sensitivity, sulphur dioxide, tolerance     

Pollination systems in pioneer trees of the genus Macaranga (Euphorbiaceae) in Malaysian rainforests

Many species of Macaranga (Euphorbiacae) are fast‐growing pioneer trees with an important role in early succession in south‐east Asian rainforests. Within the genus, diverse types of ant–plant associations exist and it has therefore been a model system for studying mutualistic interactions. Little information existed up to now, however, on its reproductive biology. Our comparative study in the genus Macaranga in Sundaland revealed specific flower characteristics and uncommon brood‐site pollination systems: enclosed inflorescence morphologies with narrow entrances strongly restrict the set of flower visitors in many species. Thysanoptera were the most abundant insects in 20 of the 26 investigated Macaranga species and, in three species, heteropteran adults and larvae were dominant. Both insect groups used the flower chambers as breeding sites and fed on nectar‐producing trichomes inside the bracteoles. Thrips as well as heteropterans are assumed to contribute to pollination. Different Macaranga sections were associated with different flower visitors, suggesting isolation by different pollinators. Thrips pollination and myrmecophyty often occurred in the same sections. The development of enclosed flowers might have facilitated tight ant–plant interactions and prevent ant–pollinator conflicts. However, the complex ecosystems in which the mutualistic systems evolved are rapidly changed with unknown consequences for these specific interactions. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 103 , 935–953.     

Preparation of Cuticle-free Epidermal Peels for the Demonstration of Primary Pit-fields

Cuticle-free epidermal peels for the demonstration of primarypit-fields (if any) on the outer surface of the epidermal cells,can be prepared by a chemically controlled process, using 5-10per cent NaOH solution as a macerating medium. Such peels canbe obtained from any desired part of the plant within a periodof a week. The process involves allowing the trimmed piecesof the plant material to stand in the NaOH solution at 50–60°C, until all the cuticular depositions on the outer surfaceof the epidermal cells are dissolved and the unwanted tissuesare sufficiently loosened to allow the easy removal of the epidermis.The separation of epidermis is done by giving moderate agitationsin water during washing or by means of a soft-haired brush undera dissecting microscope. The peels so obtained must be washed thoroughly in water andcan then be stained with bismark brown or iron alum hematoxylln.After dehydration in ethanol, they can be mounted permanentlyin Canada balsam.     

A Comparison of Abscission of Rubber (Hevea brasiliensis) Leaves Infected with Microcyclus ulei with Leaf Abscission Induced by Ethylene Treatment, Deblading and Senescence

Studies on the histology and on effects of growth substancesand phenols as well as changes in activities of pectinmethylesterase indicated that the mechanism of abscission of Hevealeaflets infected with Microcyclus ulei differed from the mechanismof abscission of debladed, ethylene treated and senescent leaves.An abscission layer which was formed during abscission of debladed,ethylene-treated and senescent leaves was absent during abscissionof heavily diseased leaves. The ratio of pectinmethyl esteraseactivities in tissues distal to the abscission zone to activitiesin tissues proximal to the zone decreased in debladed and ethylenetreated leaves but such decreases were not detected during abscissionof Hevea leaves infected with M. ulei. Hevea brasiliensis Muell. Arg., rubber, leaf abscission, Microcyclus ulei, ethylene, indol-3-ylacetic acid, kinetin     

Mutants of phospholipase A (pPLA‐I) have a red light and auxin phenotype

pPLA‐I is the evolutionarily oldest patatin‐related phospholipase A (pPLA) in plants, which have previously been implicated to function in auxin and defence signalling. Molecular and physiological analysis of two allelic null mutants for pPLA‐I [ppla‐I‐1 in Wassilewskija (Ws) and ppla‐I‐3 in Columbia (Col) ] revealed pPLA‐I functions in auxin and light signalling. The enzyme is localized in the cytosol and to membranes. After auxin application expression of early auxin‐induced genes is significantly slower compared with wild type and both alleles show a slower gravitropic response of hypocotyls, indicating compromised auxin signalling. Additionally, phytochrome‐modulated responses like abrogation of gravitropism, enhancement of phototropism and growth in far red‐enriched light are decreased in both alleles. While early flowering, root coils and delayed phototropism are only observed in the Ws mutant devoid of phyD, the light‐related phenotypes observed in both alleles point to an involvement of pPLA‐I in phytochrome signalling.