429 



a parasite of the gipsy moth [Porthetria dispar] and the brown-tail 

 moth [Nygmia phaeorrhoea], in the control of which it has now become 

 one of the chief factors. The history of importation and colonisation 

 of this parasite, as well as the method of handling and life-history 

 under laboratory conditions are reviewed. C. concinnata has a very 

 wide distribution in Europe and attacks 58 different species of 

 Lepidoptera, a list of which is given. In America, where this parasite 

 is comparatively new, the number of hosts has increased to 33. 

 Reproduction in the laboratory was studied on Callosamia fromdhea, 

 Bomhyx mori, Hemerocampa leucostigma and Pieris (Pontia) rapae. 

 Under laboratory conditions temperature exercises very little effect 

 on the larvae, of which each female is capable of producing from 

 90 to 100, but the length of the adult stage varies greatly according 

 to the temperature and method of handling. The mode of larviposition 

 and subsequent development i^ discussed [see this Review, Ser. A, 

 ii, p. 136]. All attempts to prove parthenogenesis in this parasite 

 have failed. The extreme dates of collection of adults of this insect 

 recorded in the field are 1st May and 29th October, those for puparia 

 are 16th June and 30th September. The life-cycle occupies about 

 28-30 days, thus allowing the completion of 3 full generations during 

 the season. Full details as to hibernation have not yet been worked 

 out, but it is definitely recorded as taking place in PapiUo polyxenes, 

 F., Diacrisia virginica,, F., Deilephila galii, Rott., Deidamia inscriptum, 

 Harr., Callosamia promethea, Drury, and an unidentified Geometrid 

 from which larvae of C. concinnata emerged for pupation in the 

 spring. A single case of hibernation in Pieris rapae is recorded. 

 Attempts to carry the parasite through the winter in the adult and 

 pupal stages were not successful. Secondary parasites are known to 

 attack the larvae and puparia of C. concinnata, but only when these 

 are found above-ground. Supernumerary parasitism has also been 

 noticed in Nygmia j}haeorrhoea, from larvae of which examples of 

 C. concinnata have been observed to emerge after the Hymenopterous 

 parasite, Meteorus versicolor, Vier., had already done so. 



Since the establishment of this parasite in the United States, 

 Hemerocampa leucostigma, which was formerly a serious pest in New 

 England, has practically disappeared ; the Saturniid, Callosamia 

 promethea, has become rare ; Pieris rapae, though stUl a serious pest, 

 has been materially reduced in numbers in some areas ; the celery 

 caterpillar, Papilio polyxenes, is less common ; and the fall webworm, 

 Hyphantria ciinea, which was abundant in Eastern Massachusetts 

 in 1910, is now scarcely noticeable. Though it is not claimed that 

 this parasite is the sole cause of this reduction, its value in this respect 

 has been considerable, apart from its beneficial effect on the outbreaks 

 of gipsy and brown-tail moths. 



Clemens (W. A.). The Pine Bark Beetle {Ips pini, Say). — Cornell 

 Univ. Agric. Expt. Sta., Ithaca, N.Y., Bull. no. 383, October 

 1916, pp. 385-398, 2 plates, 4 figs. [Received 15th August 

 1919.] 



All stages of Ips pini, Say, are described and the history and 

 synonomy are reviewed. The distribution of this bark-beetle 



