INSECT NOTES. 2^ 



Achatodcs rjcac (Spindle worm). 



In June the new shoots of the elder may be found to 1 j with- 

 ered and dying- and if the twig be cut open a white cat :r])illar 

 with black spots may be seen feeding- upon the pith. fliis is 

 the spindle worm, the larva of the little moth AchcJodcs aeae. 

 The species, first described by Harris, and well known to sys- 

 tematists, has rarely since been mentioned by economic ento- 

 mologists. Besides the elder, it also is injurious to corn, dahlia, 

 and perhaps other thick-stemmed plants. In the elder twigs 

 the caterpillar when full grown gnaws towards the surface at 

 some point, usually near a twig node, pierces tlie bark or leaves 

 a thin layer unbroken, then pupates within its burrow. The 

 adults emerge in July and August. We have reared specimens 

 at Orono, Maine, bearing the date August 6, and also have 

 specimens from Ithaca, New York, which emerged July 14. 

 According to Forbes the adults in Illinois appear the latter part 

 of June. 



The full grown caterpillar, which is about one inch long, is 

 yellowish white in color with flat blackish tubercles each with 

 a single bristle. On the first and second abdominal segments 

 the tubercles are arranged as follows: one on each side of the 

 mid-dorsal line, a second behind and below this, four grouped 

 around the spiracle of which the third is above and slightly in 

 front of it, the fourth behind, the fifth very small, in front and 

 above, the sixth directly below it ; the seventh to the tenth are 

 on the ventral side of the segment, the eighth being very much 

 smaller, and the seventh of the first segment bears two bristles. 

 In some specimens and on some segments the third and fifth 

 tubercles are nearly or quite fused. The preanal and the anal 

 plates (fig. 26) are contiguous but not fu.sed. The hooks of 

 the abdominal legs are uniform in size, about 22 in number, the 

 circle being widely open outwardly. The palpi of the second 

 maxillae arc short and thick (fig. 24). 



The pupa is reddish brown in color, over half an inch in 

 length, at the head end with two stout rounded tubercles, the 

 posterior end with the stout spines (fig. 27). The adult, which 

 cx])ands over an inch, has rust red fore wings mottled with 

 gray, with orange spots near the tip. and yellowish gra}- hind 

 wings. It is figured by Holland in his Moth Book. 



