BIOLOGIC NOTES ON SPECIES OF DIABROTICA. 83 
were found to have been scraped nearly bare, and in a few cases the 
larve had buried themselves in the main root. All observed were 
nearly mature. One larva made a cell April 17, pupated April 21, 
and the adult developed April 28. Other beetles developed April 30 
and May 1. 
During May beetles were observed, but no injury was noticed or 
reported. ; 
June 10 the beetles were abundant at McAllen, Tex., feeding on 
the foliage and rinds of watermelons and disfiguring some of the 
melons. The foliage in some places was badly riddled, but the crop 
was so far advanced that this caused little damage. Many beetles 
hid during the middle of the day among cabbage and Amaranthus 
leaves for protection from the sun. 
The life history of one generation of this species was worked out 
as follows: 
Record of a single female of Diabrotica vittata placed in confinement April 26, 1909. 
AG Uaoneene see io seesae 4 Elacedain-confinement. 
IE ee ot te a eee BAe win acs as) te 42 eggs deposited. 
Mca pelll feces yerape, Revetape 5 ey scent are = 42 eggs hatched. 
1 Le NER ON es First larvee made cells. 
JSS Wh A First larvee pupated. 
Mary gD see ee een nea Seo First adults developed. 
IC 6 Eee oe so, ee re First adults issued. 
dU ake vS ee ee All adults had issued. 
The stages were as follows: 
Days 
Blcpeetee tC eeee ee eee asics sae fen ator iste eMac ts oo) es « efeiare 8 
TLS SE ISU CN Re ee ee Bin See een a Ry A a 14 
Jeejgall UNC 24 es ore Sea OO a ea et ee a eee eee oe 5 
ANTE 05 tS he rsh eo Gs Cae AT TE a aN AE Pa a Sa 27 
The mature larvee were in the cells three days before pupating and 
the adults remained in the cells from one to four days before issuing. 
The first pair of these beetles mated June 4. and the first eggs, 20 in 
number, were deposited June 11. 
On May 3 another female deposited 58 eggs and the following 
record was obtained: 
Days. 
TDiner Gide Cu eens Lee ee oc ee ot ens ee eee ree ie ceca 7 
bei ctienl sire tes: pee e OPCS Le, = he ean anne Re PE Eh Ee ore 15 
Peifoa lbntace sae een a ey ete eee ci. 2 =. Se dye era en crepene oa 5 
BIR tel sere et ee eee crete cic Saal es ee eee eRe Ae 2 27 
During the first weeks of May, when this species was being reared, 
there was a period of excessive humidity. The larva were supplied 
with sections of cucumber vine as food. The humidity caused this 
food to decay very rapidly and this necessitated frequent renewal, 
and as a result many larve died and only a relatively small propor- 
tion was carried to maturity. The temperature during May, 1909, 
