138 Transact tons. 



produced do not always find a dead sheep on which to lay their eggs, and 

 therefore they are urgently attracted to any place where there is the faintest 

 scent of animal matter. I have seen C. quadrimaculata so violently impelled 

 to lay her eggs somewhere that she has done so on a bicycle-tire where it 

 had just been pressed with a perspiring hand. 



After nightfall the swarms of moths are as insistent as are the blow- 

 flies by day. These night-flying honey-suckers are represented by about 

 twenty species, and, as these were obtained chiefly round the lamp in the 

 living-room of the station, definite search would probably double the number 

 of species. Now, the day-flying honey-suckers number only eight species, 

 and the disproportion in individuals is much greater. The entomophilous 

 flowers of the neighbourhood, therefore, must depend chiefly upon night- 

 flying insects, and the colours of their flowers should be most commonly 

 white, or some pale tint, rather than the darker colours of red, blue, or deep 

 yellow. 



An examination was made of the list of plants near the station as given 

 by Cockayne and Foweraker, and the colours of such of them as produce 

 nectar were taken from Cheeseman's Manual of the New Zealand Flora. The 

 examination showed that fifty-one native plants were described as having 

 flowers either white, rosy white, or pale blue or white, while only sixteen 

 were described as yellow, red, blue, or brown. Dr. Cockayne has pointed 

 out to me the undeniable fact that, to the human eye at least, white 

 flowers are much more conspicuous even by day than those of any other 

 colour, so that it would probably be quite incorrect to regard every white 

 flower as cross-fertilized by night-flying insects. At the same time, given 

 the nocturnal or crepuscular honey-suckers, it would obviously be advan- 

 tageous for the plant to have white flowers : abundance of such flowers 

 would encourage the multiplication of the insects that depend on them 

 for their food; so that the large excess of plants bearing white or pale 

 flowers is here regarded as an important factor in the character of the 

 insect population. 



B. The Insect-associations. 



The above term has been used to indicate that, as the plants of the area 

 are grouped into definite associations depending on environmental con- 

 ditions, so the insects are grouped together according to their environment, 

 of which, of course, the plant-covering is the most important factor. The 

 insect-associations have been named more or less closely after the plant- 

 associations, partly to avoid multiplication of names, and partly because 

 the plant-covering is more conspicuous and forms the determining factor 

 in the character of the insect-association. The range of species in an insect- 

 association is, of course, not so clear-cut as in the plant-associations ; for, 

 while one may be able to say to a yard where tussock ends and swamp 

 begins, the insects proper to one kind of environment may be found flying 

 over the plants of another — as, for instance, when dragon-flies or sand- 

 flies are found on the tussock. Again, insects that feed on the plants of 

 one association may take shelter in another, as in the case of numerous 

 moths which probably feed on the flowers of the shrub-land, but shelter 

 by day in the forest, or may be attracted by night to a light on the 

 tussock. The variety of plant-associations in close proximity to the 

 station is a great advantage from most points of view, but in the present 

 instance may lead to some errors in assigning certain insects to their proper 

 associations. 



