[Aroid-l] leaf beetles on aroids

From: eugene_hoh at yahoo.com.au (Eugene Hoh) on 2008.05.21 at 21:11:30(17600) hi Peter, Christopher & all, At the International Aroid Symposium in Kuching back in 2004 (as some of us on aroid-L will remember) there were some very interesting presentations on animal-plant interactions - and one of these was, indeed, a paper on beetles cutting circular holes in aroids, by entomologist Christopher Darling. Apparently these cuts allow latex (unpalatable to beetles?) to drain from the encircled areas, which are subsequently eaten. Darling's study was conducted in Vietnam - but during the symposium field trip he pointed out similar holes occurring in some local aroids (eg. Alocasia sp. - A. scabriuscula??) which we saw growing near roadsides and streams. All the holes seemed to be about the same size. Here's a link I've found, to a published paper: http://www.eeb.utoronto.ca/system/files/2007_Darling+_Holey_aroids_Biotropica.pdf In case the link doesn't work, the reference is: Biotropica 39(4), 555-558, 2007; and the species studied were the beetle Aplosonyx ancora (Chrysomelidae), Alocasia navicularis and Colocasia gigantea. The paper also mentions that the Philippines is within the range of the genus Aplosonyx, and all the recorded host plants of the genus are aroids (C. esculenta is one). Hope this is useful. cheers Eugene +More --- Christopher Rogers wrote: > Hiyer, Peter! > > > > I would very much like to see you pictures. You > called them leaf beetles. Do > you mean that you think they are chrysomelids? > > > > Happy days, > > Christopher > > > > > > D. Christopher Rogers > > Senior Invertebrate Ecologist/ Taxonomist > > ((,///////////=======< > > > > EcoAnalysts, Inc. > > 1.530.756.4481 > > 1.530. 383.4798 (cell) > > 1307 "L" Street > > Davis, CA 95616 > > USA > > > > ?Invertebrate Taxonomy > > ?Endangered Species > > ?Ecological Studies > > ?Bioassessment > > ?Invasive Species > > ?Plankton > > ?Phycology > > > > Moscow, Idaho ? Bozeman, Montana ? Woodland, > California ? Joplin, Missouri > > Selinsgrove, Pennsylvania > > ecoanalysts.com > > -----Original Message----- > From: aroid-l-bounces at gizmoworks.com > [mailto:aroid-l-bounces at gizmoworks.com] > On Behalf Of Peter Matthews > Sent: Monday, May 19, 2008 6:13 PM > To: Discussion of aroids > Subject: [Aroid-l] leaf beetles on aroids > > > > Dear Aroiders, > > > > I am currently in the Philippines (Luzon) looking > around for wild taros. > > > > Something I have noticed here is the presence of a > large beetle > > (irridescent green back, bright orange head) > frequently feeding on the > > leaves of Colocasia esculenta and very rarely on the > naturalised > > populations of Xanthosoma sagittifolium, and not at > all on the native > > Homolomena philippinensis. Nor on bananas or other > obvious garden plants. > > > > The beetle is large, about 1.5 - 2 cm long, and cuts > a circular line on > > the leaf of taro before eating out the central > portion, leaving an often > > near-perfect circular hole in the leaf. The damage > itself is quite > > beautiful. > > > > Has anyone else seen such beetles on aroids, in the > wild or in > > cultivation, in the Philippines or in other > countries? > > > > I have sme nice photos, but cannot post them until I > get back to Japan. > > > > Peter Matthews (Manila, in transit) > > > Get the name you always wanted with the new y7mail email address. www.yahoo7.com.au/mail

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