59 



NOTES ON TWO WEST AFRICAN HEMIPTERA 

 INJURIOUS TO COCOA. 



Br GERALD C. DUDGrEON, Inspector of Agriculture fok 

 British West Africa. 



(Plate YIII.) 



1. The Cocoa Helopeltis/ro^i the Gold Coast. 



The insect o£ which drawings are given here (PI. VIII, figs. 1 & 2) is one 

 belonging to the genus Helopeltis (family Capsid^), which contains a large 

 number of extremely injurious species. The most important of these at 

 present know^n is //. thelvora, Westw., the " Tea Mosquito Blight " of India, 

 which has rendered very large areas of tea-plantations in Northern India 

 unproductive owing to the puncturing of the immature leaves. II. antonii, 

 Sign., has been the cause of similar destruction to tea, cinchona and cocoa 

 in (yeylon, but in the latter plant the puncturings are upon the pod and 

 exactly similar to those produced by the species now figured. Dr. Trimen 

 referred to these in ' Nature/ xxx. p. 631, 188-1. 



The present species, of which I have submitted my specimens to Mr. Distant 

 for examination, are said by him to be in insufficiently good condition for 

 description, but he remarks that the insect is near H. schoutedeni, Reut., which 

 is recorded from the Belgian Congo. 



Fig. 1 represents the immature form, taken at Pekki-Blengo (Anum 

 district), where I found it puncturing the pods of cocoa, and injuring them 

 in such a manner that the small ones were often killed ; and even if a pod 

 reached maturity, the pulp surrounding the seeds had often been attacked by 

 fungoid growths, which had been enabled to penetrate through the decom- 

 posed area around each puncture. 



The puncturing is done with the proboscis, by means of which the insect 

 feeds upon the juices of the plant. It is not in the immature stage only that 

 the damage is done, as the winged forms (fig. 2) are furnished with a similar 

 strong proboscis and attack the fruit-pods in the same manner. 



Fig. 3 shows the upper portion of a pod from the Krobo plantations w^ith a 

 few puncturings, w^hich have only slightly distorted the shape of the pod. 



The immature insect can be recognised by the red antennae and the absence 

 of wings. In colour it is apple-green with scarlet legs, antennae, wing-cases 

 and marks on the dorsal part of the abdomen. The pronotum in all stages 

 bears a ])lunt erect spine which is red-tipped in the immature form. The 

 mature or winged form has the legs dull greenish with bands of red^ and red 

 borders to the wings and thorax. The antennae, head and tip of the thoracic 

 spine are black. 



BULL. ENT. RES. VOL. I. PART I. APRIL I91O. 



