

Washington, D. C. 



April, 1925 



THE OVIPOSITION RESPONSE OF INSECTS 



By Charles H. Richardson, Entomologist, Fruit Insect Investigations, Bureau 



of Entomology 



CONTENTS 



Page 



Introduction 



Internal physiological conditions af- 

 fecting oviposition 



Nutrition 



Age : 



Fertility 



Internal periodicities 



External influences affecting oviposi- 



tion 



Temperature 



Humidity 



, Page 

 Internal influences affecting oviposi- 

 tion — Continued. 



Light 5 



Air and water currents 



Surfaces 6 



Odorous substances 8 



Contact with chemical sub- 

 stances id 



Discussion io 



Conclusions 13 



Literature cited jj_> : JUi 



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 

 larvaj 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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