20 



m:\v vokk statp: mi'sktm 



our attention last July, by the reception of a number of gladioli 

 bulbs badly infested with plant lice, although they had been pre- 

 viously fumigated with sulfur. The insect must be exceedingly 

 prolific, since one small box containing about a dozen bulbs had the 

 interstices almost filled with exuviae and plant lice. The presence 

 of large numbers of these insects injures the salability of the 

 bulbs, since it weakens them materially and frequently results in 

 a failure to bloom. This species has caused more or less trouble 

 to some of our growers for the past two or three years, particularly 

 in late winter. Examples of this plant louse were submitted to 

 Mr Pergande, through Dr L. O. Howard, ami by him ]-)ronounced 

 to be an unknown species of aphis. 



Description. The very young plaqt louse is about .75 mm long, 

 pale yellowish or whitish transparent with an obscure subapical 

 orange band on the abdomen. The antennae are slightly fuscous 

 apically, the tip of the beak, the distal tarsal segments and the cor- 

 nicles being fuscous ; the eyes are black. The antennal segments 

 in this stage have the following measurements: Third .21 mm, 

 fourth .06 mm, fifth .141 mm. The cornicles are subcylindric. 

 being .09 X .045 mm. 



The partly full grown wingless female has the following anten- 

 nal measurements. Third segment .195 

 mm, fourth A 2 mm, fifth .085 mm, the 

 sixth .415 mm, the cornicles being sub- 

 cylindric. .135 x .06 mm. 



The full grown wingless female is rather 

 stout, a pale yellowish white, the head 

 dorsally, frequently having a distinct yel- 

 lowish cast and tlie subapical abdominal 

 segments a deeper yellowish cast on the 

 venter. The apex of the third, fourth and 

 fifth antennal segments and the apexes of 

 the tibiae, tarsi and the beak arc fuscous. The cornicles are light 

 fuscous and the eyes black. 



]Vingcd female. Length 1.75 mm. This form is dark brown 

 and yellowish, the antennae being mostly a fuscous yellowish, the 

 head fuscous, the pronotal lobes a variable fuscous and separated 

 from the mesonotum by a yellowish or deep orange area. The 

 thorax has the median and two conspicuous submedian lobes 

 fuscous. Scutellum fuscous, postscutellum light fuscous. Abdo- 

 men a variable yellowish orange and with a variable, oval, or sub- 



,f^JiatwiWwU^'| 



Fig. 6 Gladioli aphid, postc' 

 rior extremity of wingless fe 

 male, enlarged. (Original) 



