148 



Marcucci (E). Osservazioni sulla Forma estema e suUa Biologia. 



della Larva di ^^ Acanthoscelides ohtcciiis, Say." [Observations 

 on the External Structure and Biology of the Larva of Bruchns 

 obtectusA—Arch. Zool., Naples, ix, no. 2, 1920, pp. 237-262, 

 19 figs. ' [Received 18th January 1922.] 



The work hitherto done has been chiefly directed to the injury caused 

 bv, and the remedies against, Bruchus {Acanthoscelides) obtectus, Say. 

 The lar\'a does not infest beans only, many other seeds being attacked, 

 provided they are quite mature. Seeds with an oil content are injurious 

 to the larv^a, though apparently it cannot distinguish between suitable 

 and unsuitable varieties, merely preferring those that are easy to 

 penetrate. Within the bean the larva moults three times and then builds 

 the pupal cell. After remaining in the cell for some time the larva, 

 moults for the fourth time and transforms into the pupa. 



Six annual generations are possible in the region around Naples. 

 The first adults of the winter generation appear at the end of April 

 and oviposit, thus giving rise to the first generation, the development 

 of which occupies about 45 days. Towards the end of July the adults 

 of the second generation are ovipositing. The third generation, which 

 develops very rapidly, is the one that attacks mature beans still on 

 the plants, and is introduced with them into the store-rooms. At the; 

 end of August the first larvae of the fourth generation may be observed. 

 This generation develops more slowly than the preceding one, so that 

 some late pupae are present in mid-October. The adults of the fifth 

 generation begin to appear at the end of November and emergence 

 is very slow, continuing up to January. Many larvae and adults die 

 o\\ing to the low temperature at this time. Only the adults that 

 first emerge deposit eggs, and many of these do not hatch, while the 

 larvae hatched last are incapable of perforating beans. The adults 

 of the sixth generation do not appear until the end of April. 



The author's observations as to the number of generations do not 

 agree with those of other observers, but the difference is certainly 

 due to cHmatic conditions, the number being greatest in a warm 

 climate. In the hot months the adult lives about 10 days, whereas 

 in cooler months it may survive for 20 days. The adult of the fifth 

 generation, however, can remain alive for two or three months. 



Tragardh (L). Skogsinsektemas Skadegorelse under Ar 1918. 



[The Injuries caused by Insects to Swedish Eorests in 1918.J — 

 Medd. Stat. Skogsforsoksanst., Stockholm, xviii, no. 6-9, 1921, 

 pp. 281-314, 15 figs. (With a Summary in German.) 



Much damage was done by Pissodes pini, L., in Schonen, and this 

 was found to be due to the fact that thinning had been neglected 

 at the proper time, thus providing increased breeding facilities. Timely 

 thinning is therefore a preventive against this beetle. A study of 

 P. notatus, F., showed the correctness of Lagerberg's view that only 

 dying or dead trees are attacked. Only 5 per cent, of the dead trees 

 were infested, which is here explained as probably due to only these 

 being in a suitable condition in July and August, when P. notatus is 

 breeding. The infested trees had been previously attacked by a 

 fungus, Dasyscyphafuscosanguinea, and as P. ;io^a^//s breeds in unhealthy 

 trees only, its occurrence is a consequence of the attack by the fungus, 

 which it may, however, spread in the course of feeding. Magdalis 



