192 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Arthropoda. 

 a. Insecta. 



Study of Ammophila heydeni. — E. Rabaud {Bidl. Soc. Zooh 

 France, 19] 9, 44, 52-63). Description of the behaviour of this digger- 

 wasp. In beginning to burrow the insect holds firmly with the second 

 and third pairs of legs, uses her head and fore-legs, and vibrates her 

 wings rapidly. The earth is carried out in the mandibles, sometimes by 

 flight, sometimes afoot. There is considerable elasticity. After deposit- 

 ins: a paralysed caterpillar, the wasp lays an Qgg on the side of the victim ; 

 and then another caterpillar may be brought in and no o^gg laid. 

 Sometimes five or six caterpillars were collected. There is more 

 plasticity than some observers have admitted. The position of the 

 burrow is found after a flight by motor-memory ; but when the mouth 

 of the furrow was concealed the wasp w^as sometimes baffled. Though 

 she returned to the situation (by motor-memory), she could not always 

 find the disguised doorway. This points to a sensory memory. With 

 few exceptions the wasp kept to the same species of caterpillar. This 

 involved extra hunting, and its utility is not obvious, for Fabre showed 

 that the wasp-grubs can thrive on various sorts of food. The use of 

 the paralysing is not very clear, for the wasp-gmbs can thrive on dead 

 caterpillars, and they do often die. The results of putrefaction seem to 

 be trivial. J. A. T. 



Reactions of Bees to Light. — Dwight E. Minnich (Journ. Exper. 

 Zool, 1919, 29, 313-425, 17 figs.). Light exerts a kinetic influence in 

 honey-bees ; it tends to induce activity. In its absence activity is 

 greatly reduced or is entirely lacking. Isolated worker-bees, in an 

 active condition, exhibit strong positive phototropism when flying or 

 creeping. Temporary suppressions of this response may occur, however. 

 Normal bees creeping in non-directive light often move asymmetrically, 

 probably for internal reasons, for the same occurs in darkness. Bees 

 with one eye blackened usually loop towards the functional eye as they 

 creep toward a source of light. In non-directive light they generally 

 circle toward the functional eye ; this is more marked in more intense 

 illumination. The cause is the continuous unilateral stimulation. 

 Variability of response may be accounted for in many Avays. Photic 

 orientation in the normal honey-bee is eff^ected through the continuous 

 action of light on both photo-receptors. Orientation to light in 

 Arthropods generally is effected through the continuous action of the 

 stimulus rather than through intermittent changes of its intensity. 



J. A. T. 



American Insect Galls. — E. P. Felt (Bull N. Y. State Museum, 

 191S, 200, l-olO, IG pis., 250 figs.). A very useful finely illustrated 

 key to American Insect Galls and Mite Galls, arranged under the plants 

 on which they occur. No fewer than 1,441 insects are included, 682 

 being gall midges and 445 gall wasps. Besides these there are other 

 Diptera and Hymenoptera, besides various Coleoptera and Hemiptera. 



