34 PROCEEDINGS OF THE NATIONAL, MUSEUM vol. 79 



Distribution. — Michigan; Illinois (Edgebrook) ; Indiana (I)e 

 Kalb County); Iowa (Ames); Kansas; Texas; Louisiana (Baton 

 Rouge); Mississippi; Alabama (Mobile) ; Florida; South Carolina. 



Food plant. — Prickly-ash, Zanthoxylufii; orange, Citrus auran- 

 tiuni. 



Remarks. — This species has always been considered of the genus 

 Trirhabda, although its specific name called attention to its unusual 

 thoracic shape. LeConte placed it at the end of his species, remark- 

 ing that it was easily known by its very short thorax. Other char- 

 acters unite to make it unlike the other species of Trirhahda., and 

 chief among them the unusual structure of the aedeagus. The spe- 

 cies is not found on composites, but breeds on Zanthoxyluon, and 

 occasionally is a pest to orange, both of the Rutaceae. The larval 

 habits described in the introduction are also unusual as far as is 

 known in the genus Trirhahda. 



2. DEROSPIDEA ORNATA (Schaeffer) 



Plate 2, Figure 24 



Trirrhiibda ornata Schaeffer, Brooklyn Inst. Mus. Sci. Bull., vol. 1, no. 6, 

 p. 137, 1905. 



Description. — Oblong, dull, pale yellow, head without occipital 

 spot, pronotum with very indistinct indication of four spots, elj^tra 

 with Avide basal violet fascia, uniting with sutural vitta. a wide 

 lateral spot from middle nearly to apex, attaining lateral margin. 

 Head somewhat wrinkled on front, occiput glabrous without dark 

 spot. Antennae with third and fifth joints equal. Prothorax fully 

 two and a half times as broad as long, with obtusely angulate sides ; 

 surface densely and coarsely punctate, pale with faint indications of 

 four spots, two lateral, two smaller ones near middle anteriorly. 

 Scutellum entirely pale. Elytra coarsely and densely punctate and 

 covered with dense short pubescence; pale with wide, violet-colored, 

 basal band, uniting with sutural vitta, a wide lateral spot extending 

 to margin but not reaching apex or suture. Body beneath entirely 

 pale, the femora, tibiae, and tarsi darker. Length, 8 mm.: width, 

 3.5 mm. 



Type locality. — Esperanza Ranch, Brownsvdlle, Tex. 



Food plant. — Unknown. 



Reinarks. — This species is very closely related to the Mexican 

 Monocesta cyaneomaculata., which also belongs to the genus Dero- 

 spidea, and until a larger series of both can be examined, their 

 specific distinctness must remain in doubt. The only specimen of 

 cyaneomaculata I have seen has a broader prothorax, and the elytral 

 spots are not so large, although similarly placed. The sculpture 

 and pubescence are similar, however. 



