INSECTS AFFECTING THE ROOTS OR STEMS. 13 



The foregoing arrangement of five categories will be followed in 

 the body of this bulletin. Within these categories the species will 



be treated in the order of their importance. In this place, however, 

 We shall include a list of the principal species arranged as they rank 

 in importance regardless of the parts of the plant a fleeted. 



THE PRINCIPAL INSECTS INJURIOUS TO OPUNTIA IN ORDER OF 

 THEIR IMPORTANCE. 



I. Chelinidea, 3 species. Feeding upon the joints externally. 



-2. Mimorista flavidissimalis (J rote. Attacking joints externally 

 at first but later invading inner portion. 



3. Narnia, 4 species. Feeding on joints externally. 



4. Melitara, 4 species. Feeding within the joints. 



5. Moneilema, 8 species. Feeding within joints and stems. 



6. Dactylopius confusiis Cockerell and D. tomentosus Lamarck. 

 Feeding on surface of joints. 



7. Marmara opuntiella Busck. Forming mines beneath surface of 

 joints. 



8. Asphondylia, 3 species. Feeding on interior of fruit. 



9. Stylopidea picta Uhler. Feeding on surface of joints. 



10. Diaspis echinocacti cacti Comstock. Feeding on surface of 

 joints. 



II. Ozamia lucidalis Walker. Infesting the fruit. 



12. Platynota rostvana Walker. Feeding within the fruit. 



13. Polistes, 3 species. Feeding on the fruit. 



INSECTS AFFECTING THE ROOTS OR STEMS. 



Species of the ,Genus Moneilema. 



Among the insects which affect the roots or stems the most impor- 

 tant forms are eight species of the cerambycid genus Moneilema, to 

 which the common name "Opuntia longicorns " may be applied. 

 These are wingless, robust, shining black beetles, 1 from about 15 to 

 25 mm. in length. (See PI. I.) They are to be found upon the 

 Opuntia plants as adults throughout the season. In the adult stage 

 they do considerable injury by gnawing the edges of the newly 

 formed joints. This injury, however, is insignificant in comparison 

 with that done to the stems and roots by the larva?. 



The most important species of Moneilema in Texas are M. crassmrb 

 Le Conte and 31. ulkei Horn. These are widely distributed in the 

 State. Other species are. included in the list at the end of this bul- 

 letin. 



It is interesting to note that the work of the adult beetle sometimes 

 results in the dissemination of the plant. Frequently the beetles cut 



1 One species, ulkci } is opaque, its surface mottled with whitish. 



