324 



Pink Bollworm Notes. — Agric. News, Barbados, xx, no. 494, 2nd April 

 1921, p. 106. 

 Reports from Montserrat, where the pink bollworm {Platyedra 

 gossypiella) has lately been discovered, indicate that in that island 

 this moth also breeds in okra [Hibiscus esculentus] ; attempts are 

 consequently being made to provide a close season for this plant to 

 coincide with that for cotton. The pink bollworm has now appeared 

 also in Nevis and St. Croix. 



VAN DER GooT (P.). De Invoer op Java van een nieuw en nuttig 

 Lieveheersbeestje {Cryptolaemus nionirouzieri) . [The Introduction 

 into Java of a new and beneficial Coccinellid, C. montrottzieri.] 

 ■ — Tevsmannia, Batavia, xxxi, nos. 10, 11-12, 1920, pp. 456-473, 

 493-510, 2 plates. [Received 27th April 1921.] 



The introductory part of this paper deals with the biological method 

 of controlling insect pests in general, and its practical application in 

 Hawaii. A brief notice is given of some attempts in this direction in 

 the Dutch East Indies, and of the work done with Cryptolaemus 

 montrouzieri in California and Hawaii. 



In 1918 the author introduced this Coccinellid from Hawaii into 

 Java in order to combat the dangerous lamtoro scale, Pseudococcus 

 virgatus, Ckll. Honey-water was used for feeding during the forty 

 days journey from Honolulu to Java, where 200 individuals 

 of C. montrouzieri, 10 of Rhizobius ventralis, and 5 of Scymnus 

 biguttatus arrived alive. The last two species died without reproducing 

 themselves, but during June, July and August 1918, C. montrouzieri 

 was bred in numbers. 



The various stages of this Coccinellid are described. The larvae^ 

 especially those of the later instars, are very voracious, and imder 

 natural conditions they rapidly clear up Pseudococcus crotonis on the 

 leaves of Castilloa. The total length of the larval stage ranges from 

 13 to 23 days, with an average of 20. The pupal stage usually requires 

 6-9 days. The entire life-cycle from egg to imago requires 22-35 

 days, with an average of 30. The adults feed before mating, which 

 occurs 5-8 days after emergence. Thus a new generation is present 

 in 4-7 weeks, so that from 7 to 13 generations a year are possible. 

 The number of eggs obtained from a female varied from 64 to 176. 

 The food of the adults is similar to that of the larvae. In the labora- 

 tory Pseudococcus virgatus, P. crotonis and P. citri were freely taken. 

 Though well able to fly, the adults show Httle disposition to spread 

 by this means ; this is a disadvantage as regards the speedy control 

 of an outbreak of scales. 



In the breeding-cages portions of plants infested with P. crotonis 

 were placed as food. The green fruit of Anona mnricata (custard 

 apple) proved especially suitable after the black ants present had 

 been removed ; other material used included cacao twigs infested 

 with the same scale, and cassava stalks with P. virgatus. 



In June 1918 the first liberations were effected, and observations 

 made since then show that C. montrouzieri has been able to breed 

 naturally in Java for two years. Only small numbers have been 

 seen, however, and this seems to be due to the period when food is scarce 

 owing to the decrease of scales during the rainy season. It appears 

 necessary to keep a stock of the Coccinellid ready for immediate 

 increase and liberation at the beginning of the dry season in places 

 where scales are abundant. Without this artificial assistance C. man- 



