348 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1950 



Jiidd (1950) states that the European mantis is capable of stridu- 

 lating. He refers to the defensive attitude of caged individuals that 

 faced intruders with wings outspread and held vertically above the 

 body, at the same time curling the abdomen upward and swinging it 

 backward and forward, its sides making a rasping sound by rubbing 

 on the veins of the hind wings. 



EGG-LAYING HABITS 



The eggs of mantids are laid in groups of a dozen to 400, or there- 

 abouts. Each ootheca of the Chinese and narrow-winged mantids 

 contains an average of 200 to 300 eggs, according to the studies of 

 Fox (1939b, 1943). The eggs are deposited in layers in the midst of 

 a thick, frothy liquid, which soon hardens and becomes fibrous. Each 

 layer of eggs may consist of two or more rows, one above the other, 

 all leading up to the hatching area and the outside by the same 

 passageway. The protective covering is usually straw-colored or 

 some shade of gray or brown. For the most part, each species of 

 mantis deposits egg masses of a distinctive shape, some being elongate, 

 some globose, others ridged or bearing a peculiar apical spine. Very 

 unusual tropical oothecae, some not yet associated with any named 

 species, have been described. There is one type, for instance, that 

 consists of a chain of eggs laid on a leaf; another is a little cluster 

 of eggs suspended within the empty hollow of a thin parchmentlike 

 bladder attached like a nut to vegetation. (See Chopard, 1938.) 



A female usually deposits 2 to 5 egg masses, as many as 20 in some 

 tropical species, during a period of weeks, and the size varies. Egg 

 masses are usually attached to vegetation, such as grass or weed 

 stems, twigs of shrubs or trees, less often to stones, fence posts, or 

 the walls of buildings. In my experience the majority are within 

 3 feet of the ground, but I have found them in pine trees 8 feet from 

 the gromid. 



The Carolina, Chinese, and narrow-winged mantids apparently al- 

 ways oviposit while standing with the head directed downward. 

 When the oviposition site has been selected, the mantid stands firmly 

 in position, and a whitish material much like toothpaste begins to 

 appear at the end of the abdomen. The three down-curved, paired, 

 fingerlike valves of the ovipositor manipulate the material rapidly, 

 apparently beating it up and introducing air bubbles, while the end 

 of the abdomen steadily moves from side to side and up and down. 

 Eggs, which originate in the paired ovaries within the abdomen, are 

 deposited in this soft matrix, though they are not readily seen during 

 the process. The whitish matrix is the product of accessory glands. 

 Exactly how the parallel chambers through which the hatching 

 nymphs emerge are made so regularly is still difficult to understand. 



