Eutreta simplex

Eutreta simplex

The fully developed, mature monothalmous galls of E. simplex consist of short¬ ened and thickened terminals of sessile or short-stalked vegetative shoots formed at or just above the litter or soil surface (Fig. Id). Externally, they are subovoidal, smooth, grey-green tomentose, and bear sessile leaves with expanded, transversely oriented, fish scale-like leaf bases. The leaf blades elongate at the gall apices to form characteristic, flattened rosettes 2-6 cm in diameter (Fig. le). The lengths and widths of 38 galls (collected on Santa Rosa Mountain and containing fully grown larvae or puparia, Fig. If, lg) averaged 12.0 ± 0.4 (8-20) mm and 9.0 ± 0.2 (6-11) mm, respectively, after leaves were removed. The largely buried ped¬ icels measured up to 7.6 cm in length between gall bases and their juncture with the rhizome (Figs. If, lg). The central feeding chambers were clavoidal, open, rounded basally, narrowing apically, and measured 7.0 ± 0.3 (6-9) mm long and 3.0 ± 0.1 (2-4) mm wide (n = 17). The walls of the galls were pitted and covered with frass from larval feeding (Fig. If). The walls of mature galls were thickest basally (4-7 mm), thinner laterally (2-3 mm), and thinnest apically (< 1 mm) at the point of exit for the adult (Figs. If, lg). 

Life history of Eutreta simplex Thomas on Artemisia ludoviciana Nuttall in southern California (Diptera: Tephritidae)