APHID PESTS OF MAINE. I/I 



sensoria in a row, V with 2 or fewer sensoria besides the termi- 

 nal one. Antennal total length about i mm; III, 0.22; IV, 

 0.175 mm; V, 0.125; VI, base o.i mm; spur, 0.25 mm. Pro- 

 thoracic tubercles present. Wing about 2 mm long. Fig. 311. 

 Cornicle imbricated, 0.2 mm; tarsus, 0.075 mi^J cauda, 0.19 

 mm. Total body length about 1.25 mm. Figs. 289 and 290. 



Apterous viviparous female. A pale green form. Antennae 

 imbricated. No sensoria except usual terminal ones of V and 

 VI. Total antennal length about i mm. Ill, 0.2 mm; IV, 0.15 

 mm; V, 0.15 mm; VI base, o.i mm; spur, 0.26 mm. Fig. 



Figs. 288, 2; 



The pupse of this collection were pale green with pale brown 

 wing pads. The nymphs were pale green. 



Cotypes collected on Alisma Plantago-aquatica. Sept. 14, 

 1910, at Orono, Maine, by W. C. Woods. No. 123-10. 



Rhopalosiphum nymphaeae Linn. Several collections of 

 this semi-aquatic species have been made at Orono from Alisma 

 Plantago-aquatica by W. C. Woods. On July 14, 1909, No. 

 66-09 collection comprised apterous viviparous females, nymphs 

 and pupse from ventral leaf and crowded along blossom stalk. 

 The big apterous viviparous females had very globular abdo- 

 mens, dark olive green and mottled with greenish black. The 

 collection 95-09 made July 20, 1909 contained alate as well as 

 apterous viviparous females. Collection 122-10 taken Sept. 14, 

 1910, comprised alate and apterous viviparous females, nymphs 

 and pupse. These were all dark brownish green, the pupae and 

 apterous forms having a conspicuous white pulverulent bloom 

 on ventral thorax. The alate viviparous form of this collection 

 had a total body length of 2 mm and a wing 3.25 mm long, the 

 cornicle was 0.425 mm long and the tarsus 0.150 mm. The 

 cornicle (Fig. 291) is gently incrassate and the sparse and nar- 

 row imbrications have a fine saw-toothed edge. The prothoracic 

 tubercle is distinct and two pairs of abdominal tubercles can 

 be found as shown by Jackson (1908). The imbricated an- 

 tenna of the alate viviparous female (Fig. 292) has a total 



