ooo 



NATURE 



[July 8, 1920 



tinental side the middle section is the \v(fttest. More- 

 over, taking the divisions in pairs, there is a marked 

 difference in the comparison. In the northern and 

 central paire the "continental" section is the drier, 

 while in the remaining pair the difference is greater 

 and also reversed in sign. Prof. Terada connects this 

 anomalv with a possible "centre of action " controlled 

 by the position of the Korean promontory, but it 

 seems to be quite possible that he has overlooked the 

 probable effect of the contour of the land itself. A 

 glance at the map will show that his southernmost 

 "ocean" division is practically outside the main 

 island, which includes the northern and central divi- 

 sions and the greater part of the continental southern 

 division, so that we should naturally expect some sort 

 of anomaly in that region, apart from the fact that 

 the vertebral line of division, which is not far from 

 a meridian in the north, tends to become more nearly 

 a oarallel in the south. 



The author has adopted a good plan in using per- 

 centages instead of totals to prevent undue emphasis 

 being placed on the wettest periods and places. 



W. VV. B. 



Economic Entomology in the Philippines.^ 



ACONSIDER.\BLE portion of the Bulletin before 

 us is the outcome of work undertaken with the 

 definitely economic object of procuring and trans- 

 porting to the battlefield natural enemies of the beetle 

 Anotmda orientalis, which, by reason of the havoc 

 wrought in the larval stage on the roots of the sugar- 

 cane, is a serious pest in the plantations, and was 

 causing heavy losses in the Island of Oahu, Hawaii. 

 It is gratifying to learn that the quest of the entomo. 

 legists was' entirely successful, and that through their 

 labours the foe appears to have been vanquished, and 

 thereby all mankind benefited in the saving of large 

 quantities of one of our most valuable articles of food. 

 The ally which the entomological staff summoned to 

 the aid of the sugar-planters was the "wasp " Scolia 

 manilae. It is perhaps prudent here to indicate that 

 the term "wasp studies" must not be understood to 

 apply solely to the true Diplopterous wasps, the 

 Vespidae ; it is used in this publication as a con- 

 venient term including many families of aculeate 

 Hvmenoptera other than the bees. 



'Scolia manilae is a small black and yellow wasp 

 that occurs abundantly in the Philippines. The 

 females possess the power of detecting the presence of 

 certain subterranean beetle grubs, and, having located 

 their victim, dig down to it and deposit on its ventral 

 surface an egg from which there soon emerges a larva 

 that devours the beetle grub. The plan of campaign 

 was simple. At Los Banos quantities of females of 

 Scolia manilae were captured and placed in suitable 

 vessels in which had been placed beetle grubs of 

 appropriate age, and a sprig of foliage moistened with 

 water and honev for the personal benefit of the wasps. 

 Most of the grubs duly" received an egg; those so 

 favoured were olaced in clay cells which were packed 

 in soil in a tightly closed can, and then shipped to 

 Oahu. Here the' Scoliae of the next generation 

 emerged and were liberated. They established them- 

 selves with such success and increased so rapidly 

 that thev are now more abundant near Honolulu than 

 at their native place, Los Banos, while the pest 



1 " Philippine Wasp .Studies." Part !., DesTripfon of New Specie^. Py 

 S. A. Rohwer. Part ii., Descriptions o*" New .Species and Life-historv 

 Studies. By F. X. Williams. Report of Work of the Experiment Slat-on 

 of the H.awaian Sugar Planters' Association. F,ntomolo2:ical Series. 

 Bulletin No. 14. Pp. 186+106 figs. (Honolulu, December, 1Q19.) 



NO. 2645, VOL. 105] 



Anomala orientalis is vanishing so satisfactorily as to 

 cause wonder how the wasp maintains itself. 



The authors describe and figure twenty-six new 

 species belonging to several different families of 

 "wasps"; and the bionomics of these and others are 

 narrated with great detail by Dr. Williams. His 

 observations show that many species of these " wasps " 

 are of economic importance in keeping in check the 

 numbers of harmful insects, and suggest that an 

 important line of research is here open to the field- 

 naturalist. From the purely scientific point of view, 

 perhaps the most interesting feature of the Bulletin 

 is the frequency with which instincts and behaviour 

 that are characteristic of the most highly developed 

 social wasps manifest themselves sporadically and in 

 an incipient fashion among these solitary species. So 

 much is this the case that it becomes almost possible 

 to construct a gradually ascending series from the 

 simplest to the most highly specialised. Commencing 

 with species that differ but little in habits from the 

 Ichneumonidae, stinging and only temporarily para- 

 lysing their victim in order the better to attach their 

 egg, but constructing no nest or burrow of anv 

 description, we may pass on to those that dig burrow's 

 or build nests either unaided or in company with a 

 few other individuals, and reach the climax in the 

 elaborate dornestic arrangements and architecture of 

 our familiar social wasps and hornets. O. H. L. 



Climate of the Netherlands. 



nr HE Royal Netherlands Meteorological Insti- 

 -^ tute has recently issued, as publication 

 No. 102, "The Climate of the Netherlands with 

 Respect to Air Temperature," by Dr. Ch. M. A. 

 Hartman. Many years have elapsed since anv 

 previous discussion of air temperature in the 

 Netherlands was undertaken. The stations yield- 

 ing observations only for recent years have been 

 compared with the stations available for longer 

 periods, by which, together with the aid of stations 

 affording hourly observations, special corrections have 

 been f^und for each month and for each station 

 required to secure the true temperature from observa- 

 tions at the hours of 8, 2, and 7. At Zwanenburg, 

 situated midway between Amsterdam and Haarlem, 

 there is a series of observations from 1743 to i860, 

 and at De Bilt observations are available from 1849 

 to 19 17. The annual variation is given for twenty-four 

 years from 1894 to 1917 inclusive at twelve stations; 

 the range of temperature varies with latitude and with 

 I an increased distance from the sea. Diurnal varia- 

 I tion is much affected by the influence of the sea, 

 j which suggests the difficulty of obtaining a true mean 

 } temperature from a combination of, say, three hours, 

 I 8, 2, and 7, and of maintaining the same hours in 

 I winter and in summer, but a change of hours is 

 I recognised as not practicable. The highest tempera- 

 j tures observed are 99° F. and 97° F. at Maestricht 

 respectively on August 4, 1857, and July 28, iqii, 

 and 97° F. at Oudenbosch on June 8, 1915. The 

 lowest readings are -8° F. at Winterswijk on 

 February 7, 1895, and at Katwijk-on-Rhine on 

 February 14, 1895. Frequency of different tempera- 

 tures is given for several stations and for all months, 

 and the occurrences of diurnal variations of tempera- 

 ture for each degree Centigrade are tabulated, also 

 thei diurnal range for each of the twenty-four hours. 

 One of the many tables shows the temperatures which 

 occur each month, with the different directions of 

 the wind. 



