SECTION v.- TRINIDAD FROGIIOPI'ER. G{ 



tube is placed in alcohol the contained niucinoid shrinks and coaTuLites 

 and can be dissected out as a very pale yellowish substance. If this 

 coagulated material is then placed in water it quickly swells and beconi"s 

 viscid, pale bluish, translucent and just as capable of being drawn out 

 into viscid threads as the untreated material fresh from the tubes." 



On the other hand Uriel) (1918 V. p. 28) quotes Gilbeau (American 

 Naturalist 1908) as saying that the mucilaginous substance is secreted 

 by hypodermal glands known as the "Glands of Batelli." 



Some of the froth was submitted to the Government Laboratory Ijy 

 Mr. Kershaw in 1913 and Mr. Shrewsbury reported that "The frofcii 

 held for four days finally, breaking down to about O'l cc. of a clear straw 

 coloured liquid, with a decided earthy odour, which consisted mainly of 

 a solution of sodium and potassium chlorides. A small amount of 

 organic matter was also present, the nature of which has not so far been 

 determined. There is no evidence of the presence of any protein. 

 Numerously active moving protozoa were present in a minute amount of 

 sediment left adhering to the side of the tube. These were mainly of 

 two types, one oval and the other eel-shaped." 



Kershaw (1914 p. 60) states that in addition there are "numbers of 

 crystals, those of calcium oxalate are numerous, uric acid, leucine 

 pellets and urates are also present." 



The froth is of veiy considerable value to the nymph as a protection. 

 Contained in its cavities is sufficient air to supply the Jiymph for some 

 considerable time, vyhich allows it to survive immersion or temporary 

 water logging of the soil, and also makes it immune to destruction by 

 poisonous gases as found by Carinody and Kershaw (Kershaw 1913 C). 

 The covering also keeps the nymph moister in times of drought and 

 excessive heat. It also acts as a protection against contact insecticides, 

 which have to be of very great strength to kill the nymph unless the 

 froth is first removed. 



Perhaps the greatest value of the froth to the nymph is the protection 

 it affords it from the thousands of predaceous insects, particularly ants, 

 that are continually wandering over the ground in a tropical country. 



On one occasion in British Guiana the ants during the night gained 

 access to my laboratory table, entered iny breeding cages and killed all 

 adult frogboppcrs and other insects (including Syrphid flies) that I had 

 there, but the froghoiiper nymphs remained untouched. 



On another occasion in Panama I found a large army of huntinf^ 

 ants spread over a plot of grass which I knew to contain froghopper 

 nymphs. After they had passed, I made close search and found not 

 an insect living except the froghopper nymphs in their protecting froth. 



FOOD PLANTS. 

 The froghopper attacks, so far as is known, any species of grass 

 (Gramineae) and has be*en found on related plants. Foodplants actually 

 recorded are : 



GraminecB 



Sugar cane (SaccJiariun officinale.) 

 Indian corn (Zea Main.) 

 Rice. (Orijza sntiva.) 



Savannah Grass. {Paspalum conjtir/atam and P. compressum,) 

 Para Grass. {Paniciim muticum.) 

 Bamboo Grass. 



Bermuda Grass (Cijnodon dactylon.) 

 Kell}- Grass {Rotthoellia exaltatus.) 

 Cyperacece 



Scleria melaleuca. 



Razor Grass {Scleria reflexa.) 



