27 



Cirphis unipuncta, Haw. (sugar-cane army worm) causes considerable 

 damage to young crops, the caterpillars being most abundant during 

 the cooler months ; the damage in Fiji has never yet been serious. The 

 caterpillars feed at dusk on the tips of the leaves, feeding at first on 

 tender grasses until they are able to attack the harder tissues of cane 

 leaves. The larval stage lasts three weeks, pupation occurring in the 

 soil and lasting 10 or 11 days. Enemies include the minah bird, a 

 hornet, Polistes macaensis, F., a Tachinid, Sturmia himaculata, Htg., 

 a Braconid, Apanteles sp., and certain Carabids. These enemies 

 generally hold the pest in check, but, if necessary, poison-sprays 

 could be used with good effect. Cirphis loreiji, Dup., is occasionally 

 destructive to cane, but its attacks are seldom serious. Prodenia 

 lihira, F. (Mauritius-bean army-worm) is present in most plantations, 

 Mauritius beans being used as a covering crop about once in four 

 years, and ploughed in as green manure. The usual food is tobacco 

 [R.A.E., A, vi, 379]. Remedial measures are seldom necessary, 

 enemies, including the brown ant, Pheidole megacephala, F., destroying 

 large numbers of the eggs. Drachyphtijs pacificus, Dall. (Mauritius 

 bean bug) is another pest of Mauritius beans and the weeds of cane- 

 fields and is largely controlled by an egg-parasite, Ooencyrtus jMcificus, 

 and a species of Isaria fungas. Trachycentra cUorogramma, Me}T., is 

 chiefly injurious in the low-lying reclaimed swamps which frequently 

 contain a considerable proportion of sickly canes ; apparently healthy 

 stalks of Badila cane are also attacked. The damage by this moth 

 is similar to that caused by R. obscura, but the tunnels are wider and 

 shorter, and are frequently abandoned and a new one begun in the 

 same or another stalk. The larva drags about with it a case in which 

 it can quickly seek protection and pupation occurs in a very tough 

 case made of cane fibre, generally within the larval tunnel. The 

 burning of trash after harvesting and the exposure of tunnelled stalks 

 to the heat of the sun will largely check the increase of this insect. 



A new species of Cosmopteryx (cane leaf-miner) tunnels in the 

 mid-ribs of cane, especially in young plants. It is kept down to a 

 considerable extent by parasites. 



A leaf-hopper, Perkinsiella vitiensis, Kirk., in its young stages feeds 

 on the cane, sucking the sap and excreting honey-dew, on which a 

 black fungus grows ; the injury is, however, shght, the hoppers being 

 controlled by the egg-parasites, Ootetrasticlms, Paranagrus, and 

 Anagrus. A Stylopid, Elenchus tenuicornis, Curt., also attacks both 

 the young and adult stages. Aleurodes comata, Mask., is occasionally 

 very numerous on the under-surface of cane leaves, but is never an 

 important pest and is largely controlled by a Syrphid larva which 

 feeds on all stages, and is an unidentified species of Xanthogr anuria. 

 Pseudococcus bromeliae, Bch. (cane mealy-bug) is a minor pest of cane. 

 The locusts, Locusta danica, L., and CyrtacantJiacris guttulosa, Wlk., 

 are sometimes numerous along the edges of cane-fields where they strip 

 the cane leaves to the mid-ribs. The minah bird is a very effective 

 check on these locusts, which constitute its chief food. 



The hornet, Polistes macaensis, F., has only occurred in Fiji for the 

 last 15 years or so, but is already one of the commonest insects in the 

 islands. The fertilised females, after hibernating durmg August and 

 September, begin nest-building in October. The first generation 



