HYMENOPTERA 277 



There seemed to be no plausible reason for the decline. I am inclined to 

 think that the falling-off was due to a series of unfavourable seasons closely- 

 following each other, unusually heavy rainfalls will cause great destruc- 

 tion by flooding their nests. 



This, however, is only a surmise, and I do not think any exact 

 observations have been made in support of the statement. I have 

 elsewhere shown that in many parts of New Zealand humble-bees 

 do not hibernate at all, and it is just possible oviing to this that they 

 frequently succumb to the rapid falls of temperature which are so 

 common in our insular climate. Even in Otago where the winters 

 are often fairly severe — ^the mean winter temperature being 41° P., 

 and the mean winter minimum for the same months being 35° F. — 

 I have seen and recorded the bees in every month of the year. In 

 Taranaki, W. W. Smith says : " Queens of the three forms naturalised 

 in the North Island may be seen on the wing almost every day of 

 warm sunshine in the public park at New Plymouth throughout 

 winter months." 



The males appear in Otago about November, which is somewhat 

 earlier than occurs in the corresponding season in Britain. 



Mr J. Attwood of Northern Wairoa stated in 1914 that all the 

 varieties of humble-bees were common in the district, and that ten 

 years ago he noticed the large jet-black bees (either B. terrestris or 

 B. ruderatus). 



Mr W. Hone of Waverley (1914) says that more than 40 years 

 ago, Mr J. Dickie, Senr., sowed red clover on a part of his land near 

 Waverley, from which he obtained a large crop of very fertile seed. 



Mr W. W. Smith states that hive-bees occasionally fertilise red 

 clover in the shorter flowers of the heads. 



Mr Philpott informed me in 1917 that the most common species 

 in Southland is B. terrestris, var. virginalis. B. ruderatus also occurs, 

 but the other introduced species are not found in the south. 



I have not found the humble-bees visiting many of the indigenous 

 flowers either for nectar or pollen. They are very fond of the flowers 

 of Fuchsia excorticata, and frequently suck out the nectar left by 

 honey-birds or tuis, through the portions of the tube torn open by 

 •the birds. They have also been recorded on Veronica elliptica, many 

 large hybrid veronicas, Myoporum latum and Muehlenbeckia australis. 



Mr A.Philpott informs me (February, 1917) that he found humble- 

 bees not uncommon on the Celmisia blossoms on the Hunter Moun- 

 tains, at a height of 4500 ft. To get to the upland open country from 

 the Monowai flats the insects would have to traverse or pass through 

 about six miles of Nothofagus forest. 



The following species of plants which have been introduced into 



