64 



Predators of the larvae of this moth include several species of birds, 

 a wasp. Odynerus catskillensis, an unidentified Carabid beetle, a species 

 of Triphhjjs and a mite, Ancystis agilis, Banks. Hymenopterous 

 parasites mclude :—Pimph. {ttoplectis) conquisitor, Say, Microdus 

 (Bassus) earinoides, Cress., and Trichogramma (Pentarthron) minutum, 

 Riley, the last-named not having been previously recorded as a 

 parasite of the egg of the bud-moth. 



Where the usual spray calendar is followed, there should be little 

 difficulty in keeping this insect in check, as is shown by the results 

 of experiments given in this paper. The advisability of applying 

 a summer spray depends upon the conditions ; in a severe attack, when 

 the spring sprav has failed to control this pest, the application of this 

 spray at the end of June is strongly advised. When a spray is being 

 used for apple scab at this time, the addition of lead arsenate to the 

 spray is recommended in order to control this moth. Dormant sprays 

 have been tried against the hibernating larvae in February and March, 

 but were not successful, 



Moore (W.). Studies in Greenhouse Fumigation with Hydrocyanic 

 Acid. I. Temperature and Moisture as Factors Influencing the 

 Injury of Plants during Fumigation.— 7(5^/i Rept. Minnesota State 

 Entomologist for 1915-1916, St. Anthony Park, 1st December 1916, 

 pp. 93-108, 5 figs, 



Moore (W.) & Willaman (J, J.). II. Physiological Effects on the 

 Plant. — Jl. Agric. Besearch, Washington, B.C., xi, no, 7, 12th 

 November, 1917, pp, 319-338, 2 plates, 11 figs. 



During the process of fumigation hydrocyanic acid gas penetrates 

 the tissues of the plant either through the stomata or directly through 

 the cuticle, the amount of gas passing through the cuticle being 

 dependent on its thickness. Moisture on the leaves aids the gas to 

 penetrate, but is not a very important factor when the plants have 

 thick cuticles. High humidity aids penetration and after fumigation 

 tends to prevent evaporation of the acid in the cuticle ; low 

 temperature during and after fumigation has the same effect as high 

 humidity. High temperature quickly causes injury to become e\^dent, 

 but the final damage will be much less than with a low temperature. 



Investigations to determine the action of the gas on the tissues of 

 the plant show that the immediate effect is a reduction in respiratory 

 activity. Another result is an increase in the permeability of the leaf 

 septa, which causes less rapid intake of water from the stems and more 

 rapid cuticular transpiration. In cases of mild fumigation this results 

 merely in a temporary wilting ; in more severe fumigations the wilting 

 is followed by disintegration and death of the tissues. This increased 

 permeabihty is no doubt due to the reduced respiratory activity. 

 Within a few hours after fumigation the oxidase activity has returned 

 to normal, while the catalase and the respiratory activities have 

 exceeded the normal. The recovery of photosynthetic action, which 

 has been temporarily suspended, then becomes apparent, though 

 complete recovery requires two or three days. Respiration remains 

 above normal for several days. If the increase in permeabihty is not 

 so severe as to cause death of the tissues, recovery is followed in many 

 cases, as in the tomato, by a rate of growth in excess of normal. 



