Collecting larvae of the salt marsh greenhead Tabanus nigrovittatus and related species in New Jersey: comparison of methods.

Mass collections of larvae of Tabanus nigrovittatus Macq. brought to the surface by applications of dilute gamma BHC (lindane) to mowed plots [cf. RAE/B 46, 136] produced over 900 larvae between 1960 and 1963 at Leeds Point, New Jersey. These included T. nigrovittatus, T. lineola F. and a third form here called Tabanus sp. 3, a variant of T. nigrovittatus. These plots near ditch banks and on the open salt marsh yielded up to 20.6 larvae/yd2, but all died. For life-history studies and rearing to adults, drying salt-water cord grass on wire-mesh racks yielded numerous uncontaminated larvae. Larvae of Tabanus sp. 3 were collected by digging with a horticultural hand weeder at rates up to 17 larvae/man-hour in the ditch bank habitat. Collections by a flotation method produced 7 to 11 larvae/yd2 but injury to larvae was evident. Ladder transects across ditch banks onto open salt marsh showed that Tabanus sp. 3 dominated the ditch banks and that typical larvae of T. nigrovittatus are primarily inhabitants of the open, shorter-grass salt marsh [cf. 59, 128].