271 



NOTES OX A FROOHOPPER ATTACKING SUGAR-CANE AT MARIENBURG 



ESTATE. SURINAM. 



By C. B. Williams, M.A., F.E.S. 



On the 19tli June 191G, I visited for a few hours Marienburg Estate, Surinam, as 

 froghoppers had been previously reported as occurring in sufficient numbers to cause 

 injury. 



The wet season was just commencing, the first heavy rains of the season having 

 fallen the previous day and it rained heavily during part of my visit. 



The froghopper {Tomaspis tristis, F.) was found commonly on two parts of the 

 Estate which Mr. Sheddon, the Manager, pointed out as being most heavily infested 

 last year. It was not in sufficient numbers to be doing any damage at present, but 

 as the wet season is only beginning it will probably increase rapidly during the next 

 few months. 



The adult is much larger than the Trinidad species {Tomaspis saccharina, Dist.) ; 

 the female is very dark brown, with two transverse ii-regular rows of three small orange- 

 yellow spots on each fore wing ; the male is paler brown and has in addition to the 

 spots an orange yellow mark at the base of the \\-ings externally. The adults are 

 found sitting in the characteristic position, head upwards, at the base of the leaves 

 of the cane. At the time of collecting (mid-day) they were sluggi-^h and easily cap- 

 tured with the fingers. Fifteen adults were caught, of which 11 were females and 

 only 4 males. 



Eggs were not found in the wild state, but some were obtained from females in 

 captivity which were given the choice of green leaves and moist dead trash. They 

 were without exception laid in the dead trash. As is usual, they were embedded in the 

 material, but in many cases were inserted more deeply than is usual in T. saccharina. 

 Several eggs that were laid in a dead rolled-up leaf were inserted into the second, 

 third and even fourth layer from the exterior. Seven females (of which one was 

 freshly emerged and probably did not lay) laid over sixty eggs in the course of twenty- 

 four hours. 



The eggs are l-37mm, long by 0-33 mm. broad. They are pale dull yellow in 

 colour, spindle-shaped, slightly less pointed at the [posterior than at the anterior end, 

 wJiich may be visible on the outer surface. 



The young, or nymphs, were found surrounded by their froth, usuall\- under the 

 leaf-sheaths of the cane from near the ground to three or four feet up. One was found 

 in the rolled-up leaves at the top of the cane nearly five feet from the ground. I did 

 not have an opportunity of examining the roots below grouiRl but Mr. Sheddon 

 assured me that he has never seen any nymphs on the roots. This is an important 

 difference inhabit from both the Trinidad froghopper (T. saccharina) and the Demerara 

 species {T.flavilafera, Urich). 



