THE EGGPLANT LACE-BUG IN PORTO RICO. 



L'urythaica iiionavha Stal. 

 By E. T. Cotton, Assistant Entomologist, Insnlar Experiment Station. 



The growing of the eggplant Solanwui melongena, is made difficult 

 by the ravages of a great many insect pests, the worst of which is 

 imdoubtedly the lace-bug Corythaica monacha Stal. This bug is 

 Avidespread over the Island and attacks the eggplant wherever it is 

 grown, causing heavy damage when not controlled by spraying. It 

 feeds normally on the so called wild eggplant, Solan um torvum, and 

 it is on this plant that it is able to survive during the intervals 

 between crops. Solanum torvum is one of the most abundant of 

 weeds on the Island, growing luxuriantly in all parts and at all times, 

 and it is undoubtedly owing to this fact that the lace-bug is so abun- 

 dant. If it were dependent solely on the cultivated eggplant for its 

 food supply it would soon die out. but as the eggplant is seldom grown 

 at all times of the year even in the most favorable localities. 



The injury to the plant is occasioned by the feeding of the nymphs 

 and adults, which congregating in hundreds on the undersides of the 

 leaves, suck the vital juices from tlie plant. Their presence on the 

 leaves is first indicated by the appearance of small yellowish-brown 

 patches, which growing in size soon involve the entire leaf causing 

 it to dry up and fall off. It is not an uncommon sight to see a whole 

 patch of eggplant entirely denuded of its leaves. The insect has a 

 very short life cycle and multiplies so i-apidly that once introduced 

 into a field it soon spreads to every plant. 



Life-History. 



Tliis insert hi'eeds continously tlirough tlic year. The iiiatui'<> 

 female lays a large number of small, flask-shaped eggs, wliich she 

 inserts into the tissue of the leaves, until only a little more than the 

 crater-like tops protrude through the epidermis. The eggs are placed 

 singly on the undersurfaees of the leaves and are scattered over the 

 entire area. The length of the egg stage varies from five to seven 

 days with the majority hatching in six days. The following table 

 is an extract from breeding notes taken at various times of the year: 



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