PORTO RICO EXPERIMENT STATION. 447 



cols iiiul ('nil)ry<) fruits thus become veiy liable to the attacks of the 

 pod-rot fuuf^'us, 



Vinsonia steU'ifti'a occurs commonly on the cocoanut {Cocos nnci- 

 f<'i'<(). At Ponce many of these trees are dead or dyinj^ f rorii attacks 

 of Axpidiotus de>itrnci<>i\ This scale is parasitized, however, to some 

 extent b}' a Tineid moth, the larva of which forms a web over the 

 scales on the Avorst-infostod leaflets and yraduallv devours the entire 

 colony, thou*ih not soon enouij;li to save the life of the leaflet; attempts 

 to rear this interestiiiii' insect have been unsuccessful thus far and but 

 one imago was seen in situ. 



MISCELLANEOUS INSECT ENEMIES. 



A cricket {Gr-yllodeis muticus) has proved a serious pest in the sta- 

 tion's nurseries and seed beds, many valuable plants having l)een cut 

 ott' just above the ground. Tn one case freshly cut leaves were found 

 in the burrow of this insect, which had thus adopted one of the chan- 

 ga's {Scapterisem didactylua) clever habits. A cricket, presumabl}' 

 this species, was reported as doing considerable damage in the cofl'ee 

 seed beds at the cofi^ee sul)station. 



A small fly {LoiicJiwa cJialyhco)^ previously known from Brazil, has 

 caused uuich damage in the larval stage by boring into the terminjil 

 buds (rarely petioles) of cRsnava {Manihot utflissima and 3L jjalmafa 

 aipi)\ hand picking is the onh' remedy since the openings to the bur- 

 rows ar(^ closed by a granular, gummy secretion; the brittle terminal 

 bud is l)i-okeii otf and dropped on the ground where the immediate 

 ""bleeding" and withering of the bud imprisons and kills the young 

 maggots. Mature cassava plants are usually attacked by a small bug 

 of the Tingitidie (Athea.s- nigrk'ornis ?); the under surface of the full- 

 sized leaf is the only part attacked and, therefore, successfid spraying 

 is ex<-eedingly diflicult, especially since the insect is possessed of great 

 \itality. A l)rownish mite also causes injuiy to the young cassava 

 l(>af ; the epidermis of the under surface of the basal portion of the 

 l)lade is the usual point of attack. Lecaniwn hemisphsericum and an 

 undi'termined white scale have been noted on stems of cassava. 



Practically no insect enemy of the yautia {XantJiomvui sp.) has 

 been observed yet; however, a ])lack aphid was found on a plant pur- 

 chased as AJor<fi<i(t rnarxJiaUii^ ])ut believed to l)e a Xanthosoma, and a 

 mite was noted on the upper surface of the leaf blade of a i)lant l)ought 

 for Alocdsia Ixitarensis^ but which appears identical with the connnon 

 yautia known as "Guayanu^ra." 



The malanga {(^olocwiia antupuyr\nn ('Hcxdent\i}ii) is occasionally 

 attacked by an aphid which is usually parasitized by a whitish fimgus 

 and a hymen()})ter. 



A scale (Dactylopius '.) attacks tlu> "heads" of Guinea yams at 



