Date of Award

Spring 1984

Document Type


Degree Name

Master of Science (MS)


Biological Sciences



Committee Director

James F. Matta

Committee Member

Raymond W. Alden, III

Committee Member

John R. Holsinger

Call Number for Print

Special Collections LD4331.B46 B53


The Dytiscidae are one of the most distributed families of aquatic Coleoptera. In addition, they comprise one of the largest families in the order. With the exception of some European species, research in the ecology/life history of the Dytiscidae has been limited.

The patterns of appearance and disappearance of Dytiscidae were studied for one growing season, February to June, 1983, in a temporary pool in the Great Dismal Swamp. Fourteen species of larvae and twenty-four species of adults were collected. Definite temporal patterns were evident in larvae of Laccophilus spp., Laccornis difformis, Liodessus affinis, Uvarus granarius, Agabetes acuductus, and Hoperius planatus, and adults of Hydroporus spp., and Liodessus affinis. Larvae of Laccophilus spp., Liodessus affinis, and Uvarus granarius appear to reach maximum numbers in the latter part of the growing season. Emergence of Laccophilus spp. larvae appeared to be coupled with pond drying and seemed to be indicative of opportunistic resource utilization during a period of decline in predator numbers. Temporal partitioning of the habitat is apparent in Laccornis difformis and Hydroporus lobatus, two species which compete for the same food source. The larvae of Laccornis difformis attained peak abundance during early April, followed by a sharp decline. A similar pattern was observed for the larvae of Hoperius planatus in mid-April and Agabetes acuductus during late April. Although believed to be a rare species, the larvae of Hoperius planatus was observed to be the most abundant of the species collected.


In Copyright. URI: This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s).