A review of the species of Eugaurax Malloch (Diptera: Chloropidae) occurring in North America, with the description of a new species mining leaves of floating marshpennywort (Araliaceae: Hydrocotyle ranunculoides L.f.)

Abstract

The species of Eugaurax Malloch (Diptera: Chloropidae) occurring in North America are reviewed, with DNA barcoding data provided for each. Larvae of E. floridensis Malloch mine in leaves and other tissues of arrowheads (Alismataceae: Sagittaria Ruppius ex L. spp.) throughout the eastern USA and southeastern Canada. The subspecies E. floridensis vittatus Sabrosky, new synonym, is no longer considered a distinct form. Previously confused with E. floridensis, E. hydrocotyles Eiseman, new species, is a leaf and stem miner of floating marshpennywort (Araliaceae: Hydrocotyle ranunculoides L.f.), and suspected of being a recentimmigrant from South America. The known distribution of the new species based on examined specimens is limited to the USA, from Florida to Texas north to North Carolina and Ohio, but leaf mines have been documented as far north as New Jersey (USA) and Ontario (Canada). Similar species of uncertain identity occurring in Mexico and South America are discussed. Eugaurax is now known from a total of 11 New World species, four of which belong to the E. quadrilineatus (Williston) complex, which requires further study to resolve species limits. This complex, which is easily distinguished from E. floridensis and E. hydrocotyles, is discussed briefly; it occurs in the southeastern USA (Florida to North Carolina and Louisiana) and Mexico, as well as in Central and South America and the Caribbean. Specimens of the E. quadrilineatus complex were apparently reared from eggplant (Solanaceae: Solanum melongena L.) in Florida nearly a century ago, but its larval biology and host range remain unknown.