- 2 - 
Species Responsible for Damage 
Fifteen species of May beetles taken while feeding on pecan in 
Louisiana, 1934-1937, were as follows: 
1 
Phyllophaga bipartita (Horn) 
2 
P. prunina (Lee . ) 
3 
P. praetermissa (Horn) 
4 
P. conerua (Lee . ) 
5 
P. profunda (Horn) 
6 
P. mi cans (Knoch) 
7 
? ■ arkansana ( Sch f . ) 
3 
P. karlsioei (Linell) 
9. 
P 
10. 
P 
11. 
P 
12. 
P 
13. 
P 
14. 
P 
15. 
P 
trist is (F. ) 
calc eat a (Lee . ) 
vehemens (Horn) 
gracilis (Burn ) 
fervida ( F . ) 
f utilis (Lee. ) 
implicita (Horn) 
Observations of feeding and records on the number of specimens taken 
have indicated that the first seven species listed were responsible for most 
of the injury to pecan in Louisiana. Phyll ophaga bipartita (Horn) was more 
abundant on pecan than all the other species combined. 
Apparently, the species responsible for the most damage may vary in 
rent localities of the pecan belt. Langston 2/ listed the pecan as a 
food plant of 33 species of May beetles in Mississippi. 
Other Trees Fed upon in Louisiana 
In addition to the pecan. May beetles were observed to cause partial 
or complete defoliation of hickory, post oak, red oak. persimmon, sweet 
gum, black gum, elm, and willow. Some damage is caused by the beetles in 
feeding on buds of roses before the flov/ers open. 
Feeding Period 
In Louisiana, May beetles usually begin feeding on pecan during 
latter part of March, shortly after the buds begin to open. The dates on 
which May beetles first appeared at Shreveport. La., over a period of 3 
years were: 1935, March 19; 1936, March 24; and 1937, March 22. 
Late in March and early in April the extent of beetle feeding on 
pecan is influenced by the temperatures prevailing at night. The beetles 
feed only on warm nights, and very few smerge from the soil when the temper- 
ature falls below 70° F. at dusk. In 1935 the May beetle damage to pecans 
began on March 26, but practically no feeding occurred during the period 
April 6-14, with prevailing temperatures ranging from 44° to 65° F. In 1937 
the first flight of beetles was observed on March 22. but low tempers 
prevented damage to pecans from that date until April 10. The most exten- 
sive feeding on pecan occurs from April 15 to May 15 and is practically over 
by June 1 in northern Louisiana. Pecan trees defoliated by the be 
begin to recover during the latter part of May. 
2/ Langston. J. U. 1927. Phyllophaga of Mississippi 
Agricultural Experiment Station Technical Bulletin No. 15. 
Missis 
