SECTION V. — TRINIDAD FROGHOPPER. 55- 



Variation. The markings of the wings are of two quite distinct 

 types, a light form and a dark form, each of which is slightly different 

 in each sex. 



Dark Form. (Plate I, Fig. 3 female. Fig. 4 male) (Type form of 

 Distant 1909). The ground colour of the wings is a dark chocolate brown, 

 across which run two narrow pale brown bands. The front band, at 

 about one-third the wing length from the base, is narrowest towards 

 the hind margin of the wing and expands slightly towards the 

 base of the wing near the costa, giving a curved appearance. The 

 second band, at a little more than two-thirds the wing length from the 

 base, is narrower, straighter and also slightly expanded on the costa. 

 The outline of these two bands is more distinct in the male than in the 

 female and the colour is paler cream in the former and a more yellowish 

 brown in the latter. Beyond the outer band the wings are slightly 

 more hyaline. 



Light form. (Plate I, Fig. 1, female and Fig. 2, male) (Varieties 

 A. & B. of Distant 1909 and Var. distanti and var. tricolor oi Lalleniaiid. 

 1912 p. 97.) The ground colour of the wing, and the outer band are 

 similar to the previous form, but the whole basal third of the wing is 

 light with the exception of an oblique brown streak which runs across it 

 along the claval suture. The markings of the male are again more sharply 

 defined and paler than those of the female. The internal light basal 

 portion of the wing {the clavus) of the female of this variety is very 

 distinctly darker than in the male. 



Although each of these two forms is subject to slight variations, 

 they are always readily distinguishable from each other and for some 

 time I suspected that we had to deal with two related species. An 

 examination of the genitalia however failed to show sniy constant 

 difference, and as they were later found to interbreed quite readily they 

 probably repres'ent Mendelian varieties. 



Both forms are found side by side, but the light variety is usually 

 more abundant than the dark form. This excess is in most places slight 

 (up to fJO per cent.) but in the district round Sangre Grande I have 

 alwaj's found a very large excess of the light form, the dark one being 

 quite uncommon. Table III shows the proportions in specimens 

 (Mptnrod afc random by hand or light ti'aps. There is no reason to 

 sui)nose that one variety is more likely to be captured than the othei. 



TABLE III. 



District. 



Northern Sugar Area... 

 Central Sugar Area 

 Southern Sugar Area 

 Sangre Grande 



Observations of specimens seen pairing in the field showed in 20 

 cases both sexes of the same variety and in 16 cases opposite forms. 



Occasionally a variety is found in which the eyes are bright red 

 instead of the normal black. AVithout special search I have seen six 

 such specimens in the course of three years. It is not an immature 

 stage as the insect normally develops the full black of the eyes before 

 leaving the last froth formed by the nymph. 



A similar variety has also been seen in other species e.g., T.Jlavilateru,. 

 T. puhcscens and an unidentified related species in Panama. 



PKOPORTION OF SEXES IN THE FIELD. 



The two sexes appear to be in more or less equal proportion in the field. 



Urich (1913 C. p. 18) says that 51 per cent, of the adults in the fields 

 during the day are males. 



