Prodiplosis morrisi

Prodiplosis morrisi, new species

Adults of a new species of Prodiplosis were reared from larvae found in leaf curl galls on Populus deltoides by R. C. Morris of the Southern Forest Experiment Station in Stoneville, Miss. In the spring the larvae cause a curling of the edges of young, growing leaves of cottonwood to form a green, elongated, roughly cylindrical cell, the interior of which is covered with a mucous substance. The many larvae in each cell drop to the ground to pupate at about the time the leaves are fully grown and leave the damaged leaves behind. The leaves usually are not completely killed; only the affected edges turn brown, and the midrib areas and apex remain green. Larvae in leaf galls were found at several localities in Stoneville (June 17, 1965) and in Beaumont, Texas (May 27, 1965). Six adult males were reared from a Stoneville collection on June 27, 1965. Also, late in July 1965 Morris found the typical damage on cottonwood leaves in Washington, D. C, though the midge larvae were no longer in the leaves. 

Felt (1940) reported apparently this same gall, "marginal, greenish or purplish leaf rolls or folds" in Populus sp., as being formed by Cecidomyia sp. Kieffer (1909) described larvae causing a similar gall on P. tremula L. in Europe as Contarinia tremulae; however, his short description of the larva does not fit that of the new species.

Material Examined.—Holotype: Male; "Stoneville, Miss.: reared 6/28/1965; R. C. Morris; Hopkins 51521; slide 6. USNM Type no. 68761." Paratypes (all with same date and locality as above) : 5 $ on slide numbers 1-5, 1 pupa (9), 3 pupal exuviae and 14 larvae. Other material: several prefinal-instar larvae from Beaumont, Texas; 5/27/1965; R. C. Morris. All specimens deposited in U. S. National Museum collection.

A new species of Prodiplosis (Diptera: Cecidomyiidae) found in leaf curls on Populus deltoides