et ie 
weiartee 
: 
Washington, D. C. Vv _ April, 1925 
THE OVIPOSITION RESPONSE OF INSECTS 
By Cuarres H. Ricwarpson, Lntomologist, Fruit Insect Investigations, Bureau 
of Entomology 
CONTENTS 
Page Page 
rat OCT Ct OTe ee Se Ae SE 1 | External influences affecting oviposi- 
Internal physiological conditions af- tion—Continued. 
fectine VOVIpOStiOne 2s ee 2 OUD te aaa VE EALS ate Co ey ee 5 
JOTI OM. a ee 2 Air and water currents________ 6 
PS Jaa Bt aI AS NSS fe igre ane Le ee 2 Suifa'ees elas ee A ae 6 
IGIsullitaypeene Ose ea eS ee eke 2 ie Odorous substances —-_--__-_ = __ 8 
Internal periodicities _________ o Contact with -chemical  sub- 
External influences affecting oviposi- SCAN CES) ay ee ae 2 ee 10 
PLONE Pe CLM NG RS HEAP A ee 3 DIS CUSSTONe sae teu hes Ne, bon 10 
ReMPErAhyne we we eS ie ee 3 COMMISION SS: cet eee he wa ee eae 13 
PUP yee ee RR i 4 PALE La ture iciGedt 214 si aes Rees ea 13 
INTRODUCTION 
Insects are generally attracted to materials for three purposes: 
(1). To obtain food for themselves or their progeny, (2) to lay their 
eggs, or (3) to gather material for their nests. In some instances 
the food of the adult and young is the same, and the eggs are laid 
directly on the substance which the adult eats. But there are many 
insects which show no such relation, in which the adult leads some 
part, often a considerable part, of its life in an environment very dif- 
ferent from that of its immature forms. Furthermore, certain adult 
insects do not feed at all, yet are able, in some manner, to deposit 
their eggs in locations which favor the ready access of the young 
larvee to their acccustomed food. Indeed, there is so much precision 
on the part of many insects in the selection of a place to deposit eggs 
that students were early impressed with the idea that something 
directs the gravid female to, and induces her to oviposit upon, food. 
suitable for her progeny. 
It is the purpose of this bulletin to discuss the various stimuli 
which affect the oviposition reaction of insects. Any treatment of 
the subject at this time must, however, be considered preliminary. 
Few attempts have been made to analyze this response, although 
numerous observations are on record which contribute toward its 
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