363 



FuLLAWAY (D. T.). Report of the Entomologist. — Rept.HaivanAgric. 

 Expt. Sta., 1914, Washington, D.C., 20th February 1915, pp. 43-50. 



The three principal pests of crucifers in Hawaii are the imported 

 cabbage worm, Pieris {Pontia) rapae, the cabbage webworm, Uellula 

 midalis, and the diamond-backed cabbage motli, Phitella maculipennis ; 

 the cabbage aphids, Aphis brassicae and Myzus jmsicae, are also very 

 injm-ious. The serpentine leaf-miner [Agromyza p^isilla], cutworms, 

 grasshoppers and thrips, are of minor importance. P. rapae is a 

 serious pest of cabbage grown under field conditions. It was first 

 noticed in Hawaii in 1898. The time to deal with these caterpillars 

 is before thev are half-grown ; if the plants can be started in 

 frames under partial cover, so that the butterfly is unable to oviposit 

 on them, they have a good chance of beginning to produce heads with 

 little or no infection. Arsenic sprays are recommended (arsenate of 

 lead or Paris green and Hme), apphed on both sides of the leaf. The 

 Tachinid, Frontina archippivora, undoubtedly does much to check 

 the larvae ; Chalcis obscurata has been bred from the pupa, while 

 a bacterial disease is common in this species. 



Hellula midalis is equally injurious to cabbage and related crops. 

 This pest was introduced into Hawaii between 1892 and 1895. The 

 larvae frequently destroy seedlings, older plants becoming stunted 

 or deformed. According to H. 0. Marsh, screening the seed-beds 

 and clean culture are the best remedies. The Braconid, Chelonus 

 blacJcburni, is a common parasite of this species. 



Phitella maculipennis was an early inti'oduction into Hawaii. The 

 damage to the plants results from the destruction of the leaves by the 

 larvae. Arsenic, kerosene emulsion, and hot-water sprays are recom- 

 mended against it. Multiphcation is checked by the Ichneumon, 

 Limnerium blacJcburni. The above three species are confined to 

 crucifers ; P. rapae attacks turnips and cauliflower in addition to 

 cabbage ; the larva of P. maculipennis is most injurious to thin-leaved 

 plants and seedlings ; H. undalis damages root crops, such as radishes 

 and turnips, by eating out the bud, and destroys the foliage of thin- 

 leaved plants. 



Among other pests of crucifers in Hawaii, is the Aphid, Myzus 

 persicae, which is more common than Aphis brassicae. Both species 

 are generally controlled by a Braconid, Aj)hidius (Diaeretus) rapae, 

 but the pecuUar weather conditions in Hawaii sometimes favour the 

 rapid multiplication of these pests. Such infestations may be remedied 

 by spraying with, whale-oil soap (1 lb. to 5 U.S. gals, of water), 

 biackleaf 40 (1 fluid oz. with 3 oz. of whale-oil soap and 4 gals, of 

 water), or miscible oils. 



Agromyza pusilla attacks thin-leaved crucifers, such as turnips, 

 but is of no great importance as a crop pest. The same insect under 

 different names has been found in geranium, nasturtium and beet, in 

 addition to many other cruciferous and leguminous plants. Tliis 

 pest is checked by Hymenopterous parasites belonging to the genera 

 Derostenns, Diaidinus, and Chrysockaris. Several species of thrips 

 are common, especially the onion thrips, Thrips tabaci. Cutworms, 

 including Agrotis ypsilon, A. crinigcra, and Laphijgma {Caradrinu) 

 exigua , Zinckenia {Hymenia) fascialis, Phylomelra {Plusia) chalcites, 

 as well as the grasshopper, Actractomorpha crenaticeps, have been 



