403 



of the egg varies from three to four days in summer and from 10 to 12 

 days in winter. Injury to cotton by the early generations of larvae is 

 of necessity confined to the terminal shoots, but these are deserted for 

 the flower buds and bolls when they appear. The duration of the 

 larval period in summer is about two weeks. Pupation takes place 

 in folds of the involucre or between the side of the capsule and the 

 involucre ; occasionally the cocoons are found attached to the stem 

 or leaves. The length of this stage varies in summer from 10 to 14 

 days and in winter from 35 to 52 days. It is estimated that only 

 10 per cent, of the eggs of the first generation reach maturity, while 

 of the succeeding broods about 50 per cent, give rise to adults. 



Insect enemies of E. insulana include a Lepidopterous larva, perhaps 

 Cryptoblabes gnidiella, Mill, the Braconid, Rhogas Jcitcheneri, Dudgeon, 

 and an Ichneumon, possibly Pimpla roborator, Nees. The last-named 

 species is also known to attack Gelechia gossypiella, Saund. (pink boll 

 worm). 



The findings of the Cotton-worm and Boll-worm Commission of 1912 

 indicate that the most efficient control measures are those which have 

 as their object the destruction of larvae and pupae on waste cotton 

 wood, etc., before January, Regulations for the uprooting or deep 

 cutting of plants of cotton and Hibiscus spp. before 15th December of 

 each year have had a marked effect in decreasing the numbers of 

 E. insulana. 



GouGH (L. H.). Note on Rhogas Jcitcheneri, Dudgeon and Gough.— 

 Reprint from Trans. 3rd International Congress Trop. Agric, 

 London, 1916, pp. 35-36. [Received 26th July 1916.] 



Rhogas hitcheneri is a parasite of the larvae of Earias insulana and 

 Ephestia cautella in Egypt. The number of larvae in one host varies 

 from 1 to 11, The death of the host occurs one or two weeks before 

 the emergence of the parasite for pupation. During the winter the 

 duration of the pupal stage is four or five weeks. The length of the 

 adult stage exceeds 37 days. 



Cockayne (A. H.) & Waters (R,). The Chaff-mite : Methods of 

 control. — Jl. Agriculture, Wellington, N.Z., xii, no. 5, 20th May 

 1916, pp. 372-379, 2 figs. 



During August 1915 a very severe attack of Tyroglyphus longior 

 occurred in fodder stored at Welhngton, the pest being present in 

 enormous numbers. Chaff and bran were mainly attacked ; hay and 

 oats did not appear to be damaged to the same extent, owing to their 

 offering the mites less facilities for securing food. As very Uttle was 

 known with regard to the control of mites, a series of experiments was 

 carried out. 



Investigations regarding the penetrative power of heat through 

 infested material showed the difficulty of raising a sack of chafi to a suffi- 

 cient temperature by covering it with tarpauhns and then introducing 

 into it a continuous and large supply of hot, dry air. The mites, 

 however, showed very little resistance to heat, and individuals subjected 

 to a temperature of 140° F. all died in five minutes. Mites exposed 

 for one hour to the direct rays of the sun (80° F.) all died, but the 

 effect of Ught may be important in this case. As the mites succumb at 



