U. S. D. A., B. E. Bui. 00, Part HI. Issued August 31, 1007. 



SOME INSECTS INJURIOUS TO TRUCK' CROPS. 



THE CRANBERRY SPANWORM. 



(Vicuni lilt III III iKt rill (Itn'ii. I 



A broAviiish sj)ainv()riii has been obstTVod by the writer during 

 recent years on asparagus in the District of Columbia in such numbers 

 as to indicate that it is especially attached to this crop, at least in 

 this region. In consideration of the fact that so few insects attack 

 asparagus, the accompanAnng account has been prepared. The spe- 

 cies appears to have attracted no attention since 1884," " when it 

 was considered in relation to its appearance in cranberry bogs. 

 From material recently collected, several facts hitherto unrecorded 

 ha\e l)een gained, and there are a number of unpublished notes of 

 the Bureau showing a tendeiic}^ on the part of the species to become 

 omnivorous. At aii}^ rate it is not confined to cranberry, as the 

 name given above would imply, nor to strawberr}', as might be in- 

 ferred from another name, " brown strawberry spanworm," which 

 has also been given it. The list of food plants Avhich will pres- 

 ently be furnished shows a considerable range. Owing to the fact 

 that the insect has not often been observed concentrated on any single 

 crop, little mention of it has been made in literature by economic 

 writers. Cranberry is a favorite food plant, and is sometimes in- 

 jured to a considerable extent, especially in Massachusetts. 



DESCRIPTIVE. 



This insect belongs to the lei)idopterous family (ieometridfo, tlie 

 larva* of which are well known under the common names of span- 

 worms, measuring-worms, inch-Avorms, and loopers. 



Tlte motJi which produces this spanworm is (piite variabk' in color 

 and markings. The average exjianse of wing is from a little less than 

 an inch to iipwai'd of iin inch and a fourth ( "i^-^^"'"' ) • but may 

 exceed this, attaining, according to Dr. A. S. Packard,' a measurement 

 of an inch and a half. The ground color of living specimens is pale 



<»The iiuinljer.s in superior t.vpe refei* to corresi»oniliiis iiumlters in the 

 fippemlod liil»li(>;4r:ii>liy. p. 27. 



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