I'.jTATC) I'LEA-BKETLE. 45 



Professor Forbes in tr.e 2i?t report of the State Entomologist 

 (p. ii7j says "'They are sometimes parasitized by a hymenop- 

 terous insect, probably one of the Braconidae." The other 

 observation is by Dr. Chittenden in Bulletin 19, X. S. Division 

 of Entomolog}', U. S. Department of Agriculture. He writes 

 — -'"The flea beetle fi. e. E. paravula) as well as E. cucumcris, 

 is parasitized while in the adult condition by what is evidently, 

 judging by the larvae, a species of the hymenopterous family 

 Braconidae. Numbers of beetles were collected in order to rear 

 the parasite. Larvae were first observed July 14, but none lived 

 more than a few days after issuing from the beetles. All of 

 the parasitic larvae, as far as could be learned, made their es- 

 cape from an aperture made at the anal orifice of their host." 



Tests of poisons. Tt has been frequently said that flea-bee- 

 tles cannot be poisoned, ^^d^ile this of course is not true, it is 

 well known that potato fields sprayer! in the usual way for the 

 Colorado potato beetle are not exempt from the attacks of the 

 flea-beetle. Observation has shown that the flea-beetle feeds 

 upon the unsprayed portion of the leaf and appears to avoid 

 the poisoned part. If the upper surface of the leaf is wholly 

 covered with the spray the beetle will feed on the underside, 

 where indeed it usually feeds, by preference.* If some poison 

 mixture could be devised that would prove attractive to the 

 insect it would no doubt solve the problem of flea-beetle con- 

 trol. The successful use of sweetened poisoned bait for the 

 combating the Grape Fidia (Fidia viticida) by the ento- 

 mologists at the Xew York Experiment station at Geneva has 

 suggested a trial of this method for the pot-ato flea-beetle. The 



*The peculiar feeding habit of the potato flea-beetle has been sub- 

 ject to field observation by Dr. W. J. Morse for eight or ten years both 

 in Vermont and Maine and we can do ^-!0 better than quote him in 

 this particular: — "The flea-beetles, though they may be present in 

 large numbers and doing much damage, are seldom seen by the potato 

 growers. One reason, of course, is that thej^ are so small. A more 

 important one is that they are almost always found on the under sides 

 of the leaves and eat from the under sides, never clear through the 

 leaf, stopping just short of the upper surface. They eat so nearly 

 through that the tissues above dry awa^' leaving a sm.all hole entirely 

 through the leaf. It is certain that bordeaux mixture would be much 

 more effective as a repellant to flea-beelles if it could be applied to the 

 under side of the leaACS." 



*Q\ 



