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. 
MENA Geese teccc- --6s ves -- 0 blaced in confinement. 
1 2 eat OS 42 eggs deposited. 
ISLES I aes eee apa, ene a 42 eggs hatched. 
WIR aye 2 Soo le ores ea Senet ete First larvee made cells. 
Mya ZA aban ese, J eee sf ols First larvee pupated. 
I Ley ACL We Bes ge SR First adults developed. 
WS 57 GL pe le me aa ee le nee First adults issued. 
Suites ese as cris os LIE SSS All adults had issued. 
The stages were as follows: 
Days 
[B/S RIPUS: aie cS es he sere de MN a Sa a ee 8 
J OSTA GTEREED, 02 ene Eee Ceadatrae i set eae ete OU 14 
LETRUS PIL SNE) SAG EN a Be a Ann A a eee aed ee 5 
INGE Cs Rare eae eg Ar at a rae Soe ef eA He a 27 
The mature larve 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 
LES ROG Ee ss Seam aM |G eee ee Ae Ae ea ee ee 7 
TCL STR as a AS ee nor be ge ce ONS ole 15 
1 PCOIPOIDIIL Soyer a, = es dagen ee ea apy eae ee 5 
Potal...-s BPs ae Ree eee ue ec ty ales iain LS So. 2 RU 27 
During the first weeks of May, when this species was being reared, 
there was a period of excessive humidity. The larvae 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 larvee died and only a relatively small propor- 
tion was carried to maturity. The temperature during May, 1909, 
