Matus ovatus Leech 1941

This specimen of Matus ovatus Leech was collected on June 27, 2000 near Tuskett in Yarmouth County, Nova Scotia, Canada by Jeffrey Ogden. This is the first record of this species from Atlantic Canada. In Canada they are previously known only from southern Ontario and Quebec while in the northeastern USA they have been found north to central Maine.

The specimen is 8.5 mm in length and is a uniform dark rufous in colouration. Note the deeply sulcate prosternum and prosternal process and the broadly emarginate anterior edge of the clypeus which are characteristic of this genus. The mextacoxal plate is micro-reticulate (not really visible in the photograph below) which helps distinguish this species from others in the genus. There are only four species in this genus which is restricted to North America. Only one other species (M. bicarinatus Say) has been recorded in Canada.

Larson et al. (2000) notes that they occur along the margins of rather eutrophic ponds, often amongst Typha (cattails) or decaying deciduous leaves. D. Larson (pers. com.) adds that they are often slow to move and with their brownish color are easily overlooked and consequently are not well collected.

Matus ovatus dorsal habitus	Matus ovatus head	Matus ovatus prosternum & process	Matus ovatus metacoxal plate & process

References

Larson, D.J., Alarie, Y., and Roughley, R.E. 2000. Predaceous Diving Beetles (Coleoptera: Dytiscidae) of the Nearctic Region with emphasis on the fauna of Canada and Alaska. NRC Research Press, Ottawa. 982 pp.

Many thanks to David Larson for assistance with identification and to Jeffrey Ogden for the loan of the specimen.

(c) All rights reserved. Christopher Majka & Empty Mirrors Press