262 JOURNAL OF THE WASHINGTON ACADEMY OF SCIENCES VOL. 13, No. 12 
B. limbatus oviposit in the partly opened pods of Leucaena, Pithecollobium 
and various species of Acacia. No eggs were seen deposited upon the pods. 
The seeds are irregularly pyramidal broadest and flattened at the summit. 
about 4 mm. broad and 5 mm. long with a peculiar scar-like structure at the 
summit. The rest of the surface of the seed is covered with small masses of 
a soft, reddish-orange waxy substance from which the annatto of commerce is 
derived, the source of most commercial cheese and buttercolor and of some 
inferior varnish stains and dyes for silk. The eggs are deposited singly upon 
the seed and a single Bruchus is nourished by a seed. The cotyledonsare 
broad and foliaceous disposed between thick masses of soft brittle albumen 
which is largely consumed by the larva during its development as in the case 
of the Bruchidae attacking the seeds of Hibiscus, Ipomoea and Convolvulus. 
The eggs are nearly hemispherical, but little flattened by the copious cement 
substance and show but little reticulation on the surface. The larvae as 
usual bore directly into the seed when emerging from the egg. 
The present species may be expected to continue breeding indefinitely in 
' the annatto seeds as long as they are kept at a temperature high enough, but 
little injury is done to the seeds so far as the coloring matter is concerned. 
Their presence, however, is undesirable and they would be likely to destroy 
seed designed for planting. The maceration of the seed in boiling water in 
extracting the color would doubtless destroy the insects contained in the seed. 
2. Retarded development in Eurytoma rhois. 
What was believed to be this species was found very commonly by Miss 
Marion Van Horn in the seeds of Rhus glabra and R. typhina during the winter 
of 1921-22 in the vicinity of Washington. The material collected in Jan- 
uary had the larvae full-fed and in a very thin membraneous coccoon lining the 
seed cavity. The material was brought into the laboratory of the Division 
of Stored Product Insects and held for breeding out. Few adults emerged, but 
on the examination of the seeds in February 1923 a considerable part of 
them had transformed and died without emerging probably owing to the 
excessive heat and dryness of the laboratory. There were also in the seeds a 
considerable number of living full-fed larvae. There is then in this species of 
phytophagous chalcid a phenomenon of retarded development such as has 
been recorded for the clover seed chalcid and some of the Opiine Braconidae. 
It is likely that most of the seed chalcids will be found to have the same ability 
to remain dormant in the full-fed larva for extended periods under adverse 
conditions of drought or subnormal temperatures and this will need to be 
guarded against in the control and quarantine of such insects. This phenom- 
enon is doubtless far more common than has been recorded for it is question- 
able if insects in regions with a variable winter climate or those arid regions 
where effective rainfall may be absent for a year or more could survive if com- 
pelled to depend upon steady straightforward development in conformity with 
the calendar. 
The seeds of Ceanothus americanus are infested in this vicinity by a seed 
chaleid not yet bred. As in other cases the seeds often show no external sign 
of infestation. The larva completely destroys the seed leaving only the 
coverings. 
3. Pupae of the walnut hull maggot living two years (Rhagoletis suavis Loew). 
During the fall of 1920 the writer secured many walnut hull maggots in 
and near Glen Echo, Maryland. The puparia from these were brought into 
the laboratory of the Division of Stored Product Insect investigations. 
Emergence of 23 adults was noted on March 8, 1921. From that time 
until June 21 scattering emergence continued, usually not more than one 
