2 LIFE-HISTORY AND METAMORPHOSES. 



Again, certain plants are much more productive 

 than others : thus the oak and the hawthorn (Gratxgua 

 oxyacantka) each supports five species; the ash, willow 

 (Salix, spp.), and rose (Rosa, spp.) two. Indigenous 

 ferns are quite immune, which is remarkable, and all 

 the more so as many cultivated species are subject to, 

 and not a few are difficult to cultivate owing to, the 

 ravages of these pests. 



Many Coccids found under glass confine their attacks 

 to one or two species of plants, or a single group of 

 plants ; and others, such as the " mealy bugs " (Dartt/- 

 lopius, spp.) are very general feeders, but give prefer- 

 ence to Stephanotis, Euphorbia, Lantana, Ahntiloii, 

 various palms, crotons, cucumbers, melons, vines, etc. 



The favourite localities for indigenous species are at 

 the margins or openings in woods, also trees in hedge- 

 rows and in parks and fields; while a mixed hedgerow 

 of hawthorn, sloe, bramble, wild roses, and coarse 

 grasses, having a sunny aspect, affords the best shelter 

 for several species. Certain species, however, occur in 

 the most exposed situations, and seem to endure cold 

 and wet with equanimity. Thus Riperaiti xnhti'mint'ii, 

 Newst., and Lecanopsi* formicarum, Newst., live on 

 the roots of grasses in ants' nests on the sea-shore 

 just above high water mark. I have also found <h-- 

 thezia urticx, Linn., in abundance on the salt marshes 

 at Heacham, Norfolk a most remarkable habitat, afl 

 in winter parts of the locality would be occasion all v 

 inundated. It was in the month of August when first 

 I discovered this interesting colony of Orihezia ; they 

 were then swarming over the low plants, and in some 

 instances the young insects completely covered the 

 tender shoots of Glanx maritima. We meet with the 

 same insect upon heather-clad moors far removed from 

 the sea, which latter habitat 0. cataphracta, Shaw, also 

 shares; while 0. floccosn, De Gr., loves a heather-clad 

 spot in the open wood, or a grass-covered sunny bank. 



Coccids are lovers of the sunshine, and seem to 

 thrive and multiply best in warm sheltered situations 



