433 



Other silkworms recorded from East Africa belonging to this genus 

 are A. panda, Boisd., which is probably only a \'ariety of A. infracta ; 

 A. reticulata, Wlk. ; A. ambrizia, Butl., which according to Schultze 

 is a synonym of A. reticulata, Wlk. ; A. venata, Butl., found on a 

 fruit tree {Syzygium owariensc) and Bridelia sp. ; and A . dempnvlffi , 

 Strand. Diapalpus congregarius, Strand, occurs on nearly all trees, 

 especially acacias, Ficus spp. and Miombo trees, only the young trees 

 of Cassia florida being free from nests. As many as 20 nests may be 

 found on large trees. The feeding period of this species apparently 

 coincides with the rainy season. There is only one generation in the 

 year. Oscinara signicosta, Strand, occurs on mulberry and Ficus 

 warburgii. The silk obtained from this species is considered to be 

 nearly as valuable as that obtained from the true silkworm [Bombyx 

 mori]. Other species recorded are the Saturniids, Epiphora lugardi, 

 Kirbv, and Argema mimosae, Boisd. 



Brues (C. T.). Correlation of Taxonomic Affinities with Food Habits 

 in Hymenoptera with Special Reference to Parasitism. — A^ner. 

 Naturalist Lancaster, Pa., Iv, no. 637, March-April 1921 

 pp. 134-164. 



The various phases of parasitism as studied in the parasitic 

 Hymenoptera are discussed, as is also the evolution of the characteristics 

 of the various groups, due probably to natural selection and environ- 

 mental factors. 



Certain taxonomic groups of hosts are commonly attacked by 

 ■certain distinct groups of closely related parasites ; thus Alysiids are 

 restricted to Dipterous larvae, Trigonalids to Vespids, Polygnotus spp. 

 to Cecidomyiid larvae, and Coccophagus spp. to soft scales ; but this 

 order is not reversible. It would be difficult to find examples of 

 groups of related hosts that are affected only by certain groups of 

 parasites. This restriction of parasites to certain hosts is probably 

 due to their failure to sur^'ive in any others rather than to an unvarying 

 instinct of the adult. 



As secondary parasitism is naturally dependent upon the primary 

 form it must certainly be derived from the latter. The generally 

 secluded and protected environment of the parasites probably acts 

 regularly to make hyperparasitism an easily acquired characteristic. 

 Numerous examples are quoted to explain the various theories pro- 

 pounded and an extensive bibliograph}- is appended. 



This abstract only deals with a small part of the original paper, 

 which should be consulted by those interested in the sui3Ject. 



Weiss (H. B.). A Few Insects Injurious to Ornamental Plants.— 



New Jersey Dept. Agric, Bur. Statistics & Inspection, Trenton 

 Circ. 36, May 1921, 16 pp., 8 figs. 



A brief account is here given of miscellaneous insects recently 

 found in nurseries and greenhouses in Ne\v' Jersey-. 



Chrysanthemum plants were considerabl}- damaged b\' Diarthrono- 

 myia hypogaea, F. Loew (chr\-santhemum midge), the life-history 

 and control of which have already been noticed [R.A.E., A, viii, 

 342, 364], and bav trees were attacked by Trioza a/acris. Flor 

 (bay flea-louse) [R.A.E., A, viii, 431. 



(4023) 2 H 



