67 



was bred from a Eugenia at Bangalore. Two other species of fruit- 

 flies, D. caudatus, breeding in fruits of Cucurbitaceae, and an 

 unidentified species, were captured by means of eugenol and an 

 amylvanillin solution respectively. No substance attractive to the 

 males of D. cucurhitae was found. 



The original view of the author that these odours were direct sexual 

 guides emitted by the females is as yet unproved. Crushed females 

 proved quite unattractive to the males. On the other hand, the scent 

 may not be emitted by the female, but may be termed an indirect 

 sexual guide to the plants where the females normally breed. It may 

 also be associated with food, but this would involve the assumption 

 that the feeding-habits of the males difEered from those of the females. 



Waterston (J.). Ooencyrtus pacificus, a new egg parasite from Fiji 

 {Kym.).— Bull. Entom. Research, London, vi, no. 3, December 

 1915, pp. 307-310, 1 fig. 

 A description is given of Ooencyrtus pacificus, sp. n., bred from the 



eggs of BrachypJatys pacificus, Dall. (bean bug), in Fiji. 



WooDwoRTH (C. W.). Theory of Toxicity.— J/. Econ. Entom., Concord, 

 viii, no. 6, December 1915, pp. 509-512, 1 plate. 



A study of the theory and practice of fumigation has led to certain 

 results which are represented graphically. Each curve indicates the 

 percentages of the insect eggs which failed to hatch after treatment 

 in a certain density of gas for varying intervals of time. Seven 

 theoretical curves are drawn which correspond closely with the experi- 

 mental data and show that complex relationships exist. The toxic 

 phases are represented by the following curves :— (1) the preliimnary 

 curve, in which the toxicity is directly proportional to an increasing 

 geometric series of time intervals ; (2) the deviation line or centre of a 

 zone in which the toxicity curves diverge, inversely proportional to 

 the toxicity during the preliminary period; (3) the acute curve, 

 representing a difierent physiological action of the cyamde, possibly 

 directly on the nerve centres ; (4) the compromise curve, lying almost 

 midway between the acute and stimulation curves ; (5) the stimulation 

 curve, indicating the benign effect of cyanide ; (6) the critical line, 

 representing a second physiological crisis, measuring the culnunation 

 of the violent effect of the poison and the beginning of recovery. 



The theory of toxicity put forward by this study includes the 

 following propositions :— (1) there are three separate effects produced 

 by a poison, depending on its concentration ; (2) a line of deviation 

 exists beyond which their characteristics become most evident ; (3) 

 acute poisoning reaches a maximum after which the death-rate rapidly 

 declines ; (4) these phenomena exhibit a series of definite mathematical 

 relationships. 



Craighead (F. C). A New Mixture for controlling Wood-boring 

 Insects— Sodium Arsenate-Kerosene Emulsion,— J I. Econ. Entom., 

 Concord, viii, no. 6, December 1915, p. 513. 

 During the summer of 1915, a mixture of kerosene emulsion and 

 sodium arsenate was tested to ascertain its value in controlling wood- 

 boring insects such as the Longicorn beetles. Goes sp. and Cyllene picta 



