August, ’24] HAMLIN: PRICKLY-PEAR CONTROL 459 
Gerstaeckeria spp. Tex. 4 2077 
Scavenging flies.Tex. & Fla. 10 Very large number 
A few insects sent have not been included in the above table. One 
of these was referred to in reports as Melitara (<dentata ?), but was 
later identified by Doctor H. G. Dyar of the United States National 
Museum as Melitara prodenialis Walker. I have not included this 
insect in the table because it was sent only once and later died out. 
Disonycha varicornis Horn was also sent in small numbers but it was not 
reared because it feeds on a different type of cactus from any of the 
Australian ones. 
Pathogenic Organisms Sent 
The pathogenic organisms sent from Florida include the following: 
(1) a bacterial soft-rot, (2) common anthracnose ( Gloeosporium lun- 
atum), (3) zone spot anthracnose ( Gloeosporium cactorum), (4) Colletot- 
richum sp., (5) Phyllosticta concava, (6) “pseudo-Hendersonia,” (7) 
Phoma sp., and (8) Perisporium wrightii. 
Those sent from Texas are: (1) Gloeosporium lunatum, (2) Hender- 
sonia opuntiae, (3) “white scab,” and (4) Perisporium wrightii. 
Adequate provision for the efficient carrying out of the pathological 
phase of the prickly-pear project has not been possible in connection 
with the entomological work. This field is, however, full of promise 
and deserves the attention of an expert phytopathologist. 
Accomplishments 
The insects selected for introduction from the United States include 
16 species which feed upon healthy pear, and 7 scavenging species which 
assist the plant feeders by extending the initial injury. All of these 
insects have reached Australia alive. 
None of the scavenging flies have been established due to inability 
of both Australian and American laboratories to rear them in captivity. 
Several Australian flies promise to fill the place of the American scaveng¬ 
ing flies in the cactus-insect complex. At any rate, an attempt to 
establish the American scavenging flies should be made subsequent to 
the establishment in the Australian field of the primary cactus insects.. 
Of the 16 primary cactus feeders, the midge ( Asphondylia ) and 
the fruit-worm ( Noctuelia) have failed to breed in captivity. The four 
Gerstaeckeria weevils have been eliminated on account of their unim¬ 
portant injury. The available effectives were further reduced by the 
failure of one cochineal (Dactylopius confusus Ckll.) to feed upon the 
