THE ANIMAL LIFE OF THE GROUP. 389 



been imported, however, as they bear no resemblance to the great order of 

 true bugs *'' that occur in the forests. The one previously mentioned, in which 

 the wings do not touch each other down the back, and the corn leaf-hopper,-"' 

 having the wings folded closely together on the back, are the important forms. 

 A gray sugar-cane mealy-bug,'*^ a pink sugar-cane mealy-bug,*** and a plant- 

 louse known as the sugar-cane aphis *'■' are also members of the same great 

 order.^" They are injurious locally, and though their relatives are more or less 

 readily kej^t in check on other vegetation, the latter species, when it occurs on 

 cane, hides at the base of the leaves and is almost inaccessible. 



It will be seen that some of these pests bore into the stem of the cane, 

 some eat or cut the underground roots or stems, some eat the leaves, some suck 

 the juice from the leaves and stems, and some feed on the parts left after other 

 species have had their fill. Yet in spite of the formidable list of enemies and 

 the diverse lines of attack which they pursue, some of the best and most favor- 

 ably located plantations are able to harvest as much as thirteen tons of raw 

 sugar of tlie finest quality from an acre of this seemingly pest-ridden plant. 



Apjiids or Plant-Lice. 



The sugar-cane aphis,"'' since it probalily occurs throughout the islands 

 where cane is grown, may well be taken as the type of its family."'- Tlie 

 aphids are minute insects with more than twenty species already known in tlie 

 islands, all of which have been introduced. 



Most of the species of plant-lice or aphids in Hawaii occur on well-knuwn 

 or imported plants, and were doubtless iin])ortfd with their host plants. Tliey 

 are inconspicuous but are very injurious on account of their numbers and 

 their juice-sucking habits. They make uj) in numbers for what they lack in 

 size, and must be recognized as among the greatest pests with which the 

 farmer, gardener and horticulturist has to contend. 



The plant-lice and aphids are minute, soft, pulpy little creatures with 

 rather long antennas and conspicuoi;s round ej^es ; they are commonly seen 

 crowded together on the ends of stems, the under side of leaves, in buds and 

 flowers, in clefts in the bark and sometimes even on the roots of plants. Their 

 fore wings are longer than the hind pair and repose roof-like over the hind 

 part of the body. While the majority of them are green in color, they vary 

 greatly, being brown, black, red, yellow, and variegated. They are usually 

 named after the plant on which they occur most abundantly. As a rule, thougli 

 not always, they confine their attacks to a single species of plant. Among 

 the more noticeable species in Hawaii we find the banana aphis.'"' the fern 

 aphis, •''^ the palm aphis,^^ the rose aphis."'" tlie corn aphis,-5' the violet aphis."'** 

 the orange aphis "'^ on citrus fruit generally, tlie chrysanthemum aphis,"" the 



'-- Uimililtra. *'' Peregrinug mnidis. '• Vs.u.l , „.< ,v„, ■,/,,; ,,n-;,;. *" Pseudocnrrus sarcliari. 



'" A/ihis mcchari. ^o Bemiptera. '■'' A phis sa,-,l,i,i , '■- A j:hi,l<r_ '-^ Pentalotiia ingronerrosa. 



■'' Idioiiterus nephrolepidis. ^^ Ceratniih ix hiut.mi.t '■'' M„,i <.si plnim roaic. " Aphis maidis. 



'-<' Rhnpalosiplium Holte. ^« Mi/ziia cihi.iil i,s_ ■" U.,, ■,..,.,,,/,„,„ siuibonii. 



