4 U.S. NATIONAL MUSEUM BULLETIN 243 



coating. After hatching and drying, the nymphs begin to feed at once in 

 small clusters near the empty eggshells and adults. If disturbed and scat- 

 tered, they will soon reassemble again in a cluster. 



Metamorphosis is gradual. The growth and development from egg 

 to the unchanging imaginal stage consists of five instars separated from one 

 another by successive moults. Most species in the temperate zones are uni- 

 or bivoltene and overwinter either in the imaginal or egg stage. Not much 

 has been printed concerning the biology and estivation of tingids 

 in the tropical region. 



Many kinds of plants, mostly the terrestrial flowering species, serve as 

 feeding and breeding hosts. All species are rather highly specialized in 

 their food habits, and generation after generation live on the same kind of 

 plant or closely related ones. The life cycle of each species is attuned so 

 that its breeding, egg-laying, and development period parallels in the 

 growing time with that of the unfolding of the foliar (leaf-feeding species) 

 or floral (gall-making species) parts of its host plant. 



Much injury and plasmolysis of the foliage always accompanies the feeding 

 activities. Damage to the foliar tissue increases in severity with the hatch- 

 ing of the eggs and development of the broods. Heavily infested leaves be- 

 come badly discolored, turn yellowish to whitish, wither, and often drop pre- 

 maturely. Serious losses are effected on many cultivated and wild plants of 

 prime importance in agriculture and horticulture. For example, among 

 the useful plants upon which lacebugs breed and obtain their livelihood are 

 maize, sugarcane, cotton, castor bean, pineapple, papaya, avocado, pear, 

 cherry, olive, tea, pepper, coffee, cinnamon, camphor, cacao, banana, coco- 

 nut, cassava, rubber, walnut, oak, hazelnut, azalea, and rhododendron. 



According to preliminary experiments by Nagaraj and Menon (1956), 

 recent field tests by Shanta, et al. (I960), and by Mathen (1960), the lacebug 

 Stephanitis typica (pi. 47) is accused of being a vector of a serious disease of 

 coconut palms in Travancore-Cochin, India. This disease (probably a 

 virus) is called "wilt [root] of coconut palm" and seriously affects each 

 year about one-fourth of the coconut area there under cultivation. S. 

 typica is also a pest of consequence on banana, camphor, and other 

 plants in India and the East Indies. 



As dwellers on the undersides of the leaves, tingids feed, stand, and rest 

 in a topsy-turvy upside-down position. In this inverted posture, the lacy 

 topcoat serves to conceal the body, obliterate its shadow, and thus functions 

 in ways similar to the nets or screens devised by man to hide and camou- 

 flage military installations, equipment, and troops in wartime. Lace 

 curtains hanging over a window provide the same sort of concealment for 

 mankind and objects inside a room. Diaphanous veils are worn to obscure 

 or protect the face. The inherent ability of tingids to stand or "sit" still 

 and then remain motionless for long periods is vital to survival. The least 

 movement by the bug betrays its presence on the leaf. 



