Aslamidium semicirculare (Olivier)

Flowers, Wills & Chaboo, Caroline S., 2009, Novel host records of some cassidine leaf beetles from Ecuador (Coleoptera: Chrysomelidae: Cassidinae), Insecta Mundi 2009 (95), pp. 1-8 : 5-6

Aslamidium semicirculare (Olivier) ( Figure 9–13 )

Collecting data. Ecuador, Los Ríos Province, Estación Experimental Tropical Pichilingue, sector La Isla, ex Calathea lutea Schult. (Marantaceae) , 12–VI–2007, 15–VII2007; sector Santa Rita, ex Calathea lutea , 19–VII–2008, 23–VII–2008, 15–VIII–2008, R.W. Flowers, R. Troya, J. Cedeño.

Host plants. Calathea lutea is a very large plant at maturity, with leaves measuring three to four meters high ( Fig. 9 ). It is locally called “bijao” and is used by people in the countryside of western Ecuador for thatching roofs ( Fig. 11 ) and for wrapping food eaten in the field (J. Cabanilla, pers. com.).

This cassidine species was found feeding only on the younger leaves less than a half meter in height. Adults were found on the upper side of leaves growing at heights of 44mm to 160mm. Feeding scars measured 1.5mm wide and from 1.5mm to 28mm long. No Aslamidium individuals or their diagnostic feeding scars were found on the older leaves of the mature plant, which are noticeably thicker than the earlier leaves and are covered with a thick waxy secretion on the undersides. No eggs or larvae were observed, and the number of beetles decreased between the first and last observations, corresponding to the drying out of the habitat.

Aslamidium semicirculare was also found on another species of Calathea , C. majestica (Linden) H. Kenn. ( Fig. 10, 13 ), which was growing in dense shade in a stand of mature second-growth forest at Pichilingue. Leaf scarring and observed behavior of the beetles was similar to those on C. lutea . These are the first host records for this cassidine.

Seasonality. Adults were present throughout the dry season. Numbers on leaves at Pichilingue decreased between July and August, but had somewhat increased again between August and late October 2008. No larvae have been found on either host plant.

Figures

Figure 7–13. Aslamidium and their Marantaceae hosts in Ecuador. 7) Aslamidium capense adult (Body length ca. 6mm). 8) Feeding damage of A. capense. 9) EETP technicians R. Troya and J. Cedeño under a mature Calathea lutea. 10) Calathea majestica (with author R.W. Flowers). 11) Local house with roof made of Calathea and Carludovica leaves. 12) Aslamidium semicirculare adults (Body length ca. 5 mm) feeding on young C. lutea leaf. 13) Underside of leaf of C. majestica damaged by beetle chewing.