BIOTIC ASSOCIATIONS OF COCKROACHES — ROTH & WILLIS 163 



orchids as well as the aerial roots and flower spikes of Vanda orchids 

 (Rau, 1940a). Wainwright (1898) stated that Periplaneta austra- 

 lasiae had been observed in an orchid house in Perthshire where over 

 a period of three years it had caused a good deal of damage. Skinner 

 (1905) reported that P. australasiae in greenhouses in Pennsylvania 

 showed no preference for any one plant but ate both plants and flowers 

 of orchids, roses, and carnations. Lucas (1918) received specimens 

 of P. australasiae which had played havoc with orchids especially 

 Cattleya and Vanda. Morse (1920) reported that both P. australasiae 

 and Pycnoscelus surinamensis were obnoxious in a conservatory in 

 Massachusetts where they gnawed the tips of the aerial roots of or- 

 chids. Swezey (1945) in Hawaii stated that the following cock- 

 roaches have been reported as occasional minor pests on orchids : 

 Blatta orientalis, Blaberus discoidalis, P. americana, and P. surinam- 

 ensis; he further stated that Graptohlatta notulata had been inter- 

 cepted at Honolulu on orchids from India. 



Watson (1907) stated that Blatta orientalis, Periplaneta americana, 

 and Periplaneta australasiae were injurious in the tropical plant houses 

 at Kew : "at night they come out and run or fly about among the plants, 

 devouring flowers and leaves like rabbits. Such plants as Eucharis, 

 Crinum and Alpinia, when in flower, have little chance in the palm 

 house, where the cockroaches are most abundant ; they also find out 

 the ripening bananas and soon devour them." Raffill (1910) stated 

 that in plant houses in England B. orientalis, P. americana, and P. 

 australasiae commonly, and Nauphoeta cinerea, Nauphoeta flexivitta, 

 and Pycnoscelus surinamensis more rarely, are extremely destructive 

 to plants. Flowers having a strong perfume, such as orchids, Eu- 

 charis, Crinum, and Hedychium, were often attacked while other 

 flowers nearby were left uninjured. 



Plank and Winters (1949) reported that in Puerto Rico the species 

 of Orthoptera most injurious under greenhouse conditions was Peri- 

 planeta americana. Large nymphs destroyed 25 to 30 percent of 

 freshly planted seed of Cinchona pubescens. In Hawaii the host plants 

 of P. americana are blossoms of Canna and Tribulus, and the host 

 plants of Periplaneta australasiae are Pritchardia and Sida (Zimmer- 

 man, 1948). On St. Kitts, B.W.I., young cotton plants were severely 

 attacked by P. australasiae ; this caused loss of the stand on a con- 

 siderable area and necessitated replanting (Ballou, 1916). P. austra- 

 lasiae was reported damaging the Polystichum aristatum Presl 

 [=Lastrea aristata variegata] in a greenhouse (Thilow and Riley, 

 1891). Laing (1946; British Museum [Natural History], 1951) 

 stated that P. australasiae abounds in greenhouses and forcing pits 



