THE CAMPHOR THRIPS. 21 



OCOTEA. 



Another genus closely related to Camphor is Ocotea, which is 

 represented in the southern part of Florida by the lancewood, Ocotea 

 catesbyana (Michx.) Sarg. rrofessor Watson found that efforts to 

 feed camphor thrips on this plant met with negative results. The 

 larvae died in 48 hours and the adults lived only a few days. He 

 also made an extended search of the trees in their natural habitat 

 and found no thrips on them. 



OTHER PLANTS. 



Some thrips were fed on orange and oak branches also. On 

 orange an adult lived 23 days and several larvae from 4 to 12 days. 

 On oak several larvae lived also for 10 or 12 days, and adults for 

 longer, one as long as 24 days. In neither case did they lay any 

 eggs on the plants. These experiments show, however, that life can 

 be maintained for a short time on almost any kind of plant food. 

 Even when fed on dead camphor wood, one adult lived for 21 days, 

 although most of them died in a very few days. When confined in 

 jars without any food the thrips always died in less than a week. 

 Eggs, however, were sometimes laid on the cotton stoppers. Checks 

 w~ere conducted on all these experiments by feeding thrips on live 

 camphor wood under the same conditions, and in every case they 

 were alive when the experiments were terminated. 



NATURAL ENEMIES. 



The camphor thrips is known to be the prey of lady-beetles (family 

 Coccinellidae) and doubtless has other insect enemies, both pre- 

 dacious and parasitic. A lady-beetle larva was found feeding upon 

 the immature thrips on a camphor tree, and when confined in a vial 

 ate both larvae and adults. No specific determination of this predator 

 was possible because the larva died before reaching maturity. An 

 adult of the lacewing fly Crysopa oculata Fab. was found in a cage 

 over a small camphor tree and no doubt had fed on the thrips. 

 Several dead specimens of camphor thrips collected in the field and 

 some found in the breeding jars had been attacked by a fungus, 

 but it is not known whether this fungus was the cause of their death. 

 Two insect enemies of the closely related bay thrips, Cryptothrips 

 laureli, doubtless prey upon the camphor thrips also. These are an 

 internal hymenopterous parasite, Telrastichus sp., and a predacious 

 bug, Anthocoris sp. 



CONTROL MEASURES. 



SPRAYING. 



As the camphor thrips spend the greater part of their life within 

 the cracks and lesions of the bark and in other protected places, it 

 usually is impossible to reach them with any spray material. Even 

 the most thorough application when applied at a high pressure will 

 have no effect on them when in these protected places. As a result 

 a satisfactory control can not be obtained by spraying, although on 

 warm bright sunshiny days, when the adults and larvae are feeding 

 on the buds and young leaves and running about over the trees, it 

 is possible to obtain a fair percentage of mortality by spraying. 



