656 EXPERIMENT STATION BECORD. [Vol.38 



The first 4 larval instars, of wliich there are thought to be 7, were observed to 

 require 5, 6, 6 to 8, and 18 days, respectively. The winter is pa.ssed as a half- 

 grown caterpillar, the majority hibernating after the third molt, though some 

 have been found to hibernate in the fifth, some in the third, and a very few 

 in the second, instars. This often takes place just beneath the leaf buds, but 

 may occur in any well-protected rough or angular spot on the twigs and 

 smaller branches. 



Three hymenopterous parasites have been Obtained from the bud moth In 

 Quebec, namely, Pimpla (Itoplectes) conquisitor, {Microdus) Bnssus earinoides, 

 and Pentarthron minutum. Spraying experiments with lime-sulphur to which 

 lead arsenate was added at the rate of 5 lbs. paste to 100 gal. was found to 

 be most effective when employed as soon as the leaves expanded, and next 

 in effectiveness when applied just before the petals spread. 



The pecan leaf case-bearer, J. B. Gill (V. S. Dept. Agr. Bui. 571 (,1911), pp. 

 28, pis. 3). — This is a report of investigations at a field station at Monticello, 

 Fla., of Acrobasis nehulella, one of the principal insect pests with which the 

 pecan grower has to contend. A brief account of the pest has been given by 

 the author in a publication on pecan insects previously noted (E, S. R., 38, 

 p. 157), as has studies of the pest by Herrick at the Texas Experiment Station 

 reported in 1909 (E. S. R., 22, p. 461). 



The species was first described by Riley in 1872 from a single specimen 

 reared from wild crab (Cratcegus sp.). It is a native insect that is disti'ibuted 

 more or less over the same territory as the hickories which form its preferred 

 hosts, but the author has found it very diflicult to collect the larvae on species 

 other than the pecan, even in sections where it ranks as a pest in pecan 

 orchards. There is said to be an apparent varietal resistance of the pecan to 

 its attack, some being badly infested while others are slightly so ; in general, 

 pecan trees with very small leaves seem less likely to be heavily infested by it. 



The most serious damage to pecans occurs during the early spring, when the 

 larvje feed voraciously upon the unfolding buds and leaves. Just as the buds 

 are bursting, the overwintering larvse gnaw their way out of their hibernacula 

 or winter cases packed around the buds, and migrate immediately to the tips 

 of the swelling buds, upon which they commence to feed. Some larvae have 

 been observed to eat directly through the side of the buds instead of at the tip 

 as is usually the case. The larvse, when in sufficient numbers, are capable of 

 eating the green foliage as rapidly as it appears, and it is not unusual for 

 the trees to remain defoliated for a considerable length of time. On such 

 trees the buds turn brown as a result of the feeding of the larvse and a block 

 of badly infested trees takes on the appearance of blight by fire. When the 

 infestation is less severe the larvse web and tie the tender leaves together 

 into masses, which soon become unsightly due to the wilting of the leaves and 

 the presence of particles of excrement and larval cases with which tliey are 

 united. 



Biological studies at Monticello during 1913, 1914, and 1915 in an open-air 

 insectary are reported upon, much of the data being presented in tabular form. 

 The adults, which may emerge from early May to early August, live from 2 

 to 10 days, with an average of 4.8 days, during which time as many as 182 eggs 

 may be deposited. From 6 to 9 days are required for the incubation of the 

 eggs, which may hatch from the middle of May to the first days in August. 

 the young larvre feed sparingly upon the foliage throughout the summer and 

 early fall for a period of nearly 3 months or even longer in some instance, 

 during which time they hardly attain a length greater than 0.06 in. During 

 the latter part of September they begin to seek hibernating quarters around 

 the buds, where tliey construct small, compactly woven, oval hibernacula and 



