301 



Meerill (J. H.). & Melchees (L. E.). Insects and Plant Diseases 

 attacking Garden Crops. — Kansas Slate Agric. Expt. Sta., Man- 

 halt an, Circ. no. 65, April 1918, 12 pp. 



This circular gives in tabular form the various times and materials 

 to be used for the control of insect pests of garden crops and 

 recommends several sprays, solutions for seed treatment and other 

 mixtures. 



d'Emmerez de Charmoy (D.). Report on the Importation of Scoliid 

 Wasps from Madagascar. — Dept. Agric. ^ Mauritius, December 

 1917, 5 pp. [Received 17th May 1918.] 



In certain parts of Mauritius for some time past considerable damage 

 has been done to growing sugar-cane by Orydes tarandus. Owing to 

 the successful parasitisation of the larvae of Orydes spp. in Madagascar 

 by Scoliids, the experimental importation of these was undertaken 

 in the hope that the partial control of 0. tarandus might thereby be 

 effected. 



Numerous individuals of Scolia orydophaga captured in the province 

 of Tamatave, Madagascar, were liberated in Mauritius where they 

 successfully parasitised 0. tarandus. Both sexes of this wasp live 

 exclusively on nectar and can reproduce themselves only in locahties 

 that afford a supply of blossoms continuously during six to eight 

 months of the year, especially from May to November, this being 

 the period during which the insects occur in the adult form and 

 reproduce. For this reason an adequate supply of suitable nectar- 

 bearing plants should be established on the borders and in the vicinity 

 of cane fields in the districts where it is desired to introduce the 

 parasite. The best plants for this purpose are Cordia interrupta and 

 Urena tomentosa. 



One female wasp is capable of parasitising about 30 larvae of the 

 beetle, the oviposition period extending over about 2 months. The 

 egg hatches in about 5 days and the small larva attaches itself by the 

 mouth-parts to its host. Pupation takes place in a reddish grey 

 cocoon, the adult emerging 6 to 8 weeks later. The male cocoon is 

 much the smaller. The adult insect is very strong on the wing, being 

 capable of covering long distances without fatigue in search of the 

 particular kind of food that suits it. 



The Scoliids themselves are attacked by several parasites, the most 

 important of which are Coleoptera belonging to the family Rhipi- 

 phoridae, which attack the Scoliid larvae when spinning their cocoon. 

 Their eggs are also subject to attacks by the Gamasid mites that some- 

 times infest the larvae of 0. tarandus. 



Orydes in damp locahties in Madagascar is attacked by a 

 fungus, which has been introduced into Mauritius and seems capable 

 of assuming a highly infectious character under widely different 

 conditions. 



In addition to S. oryctophaga other Scoliid wasps introduced from 

 Madagascar were : — S. cajfra, S. iridicolor and Elis roma^idi, probable 

 parasites of 0. tarandus ; Elis pfeifferi, a probable parasite of LacJino- 

 sterna ; and Elis thoracica, a probable parasite of Adoretus versutus. 



