450 FUNGUS-INSECT INTERRELATIONSHIPS 



ivebberi is so effective in controlling white fly in low-lying ham- 

 mock groves that artificial measures are unnecessary. 



Aspergillus parasiticus has been found effective against various 

 mealy bugs in Hawaii [Speare (1912)], Puerto Rico [Johnston 

 (1910)1, and California [Smith and Armitage (1931)]. 



Species of Entomophthora are not easily cultivated in pure 

 culture but, if artificially disseminated, may aid in bringing epi- 

 demics of plant lice under control. Entomophthora sphaero- 

 spervia, for example, caused considerable reduction in the popu- 

 lation of apple sucker, Psyllia mali [Sweetman (1936), p. 71], 

 in Nova Scotia and in parts of Europe. Another species, E. 

 clorojiiaphidis, was found very destructive to walnut aphis, Chro- 

 viaphis juglandicola, in California. In some seasons in Florida E. 

 fresemi becomes an important factor in the control of Aphis 

 spiraecola, especially on tangerines. 



Metarrhiziwn anisopliae, when artificially applied in some lo- 

 calities to corn leaves, has been found very destructive to corn 

 borer [Sweetman (1936), p. 75]. 



It becomes apparent to anyone who critically reads accounts 

 dealing with attempts to use fungi to control insect pests that the 

 results are not always in accord, and the conclusions are often con- 

 tradictory. Petch (1921) summarized his pertinent experiences as 

 follows: "The problem which has yet to be solved by those who 

 wish to control insects by means of fungi is to create an epidemic 

 at a time when such an epidemic would not occur naturally." On 

 the basis of the relatively few cases in which outstanding control 

 has been accomplished Fawcett (1944) suggests that more atten- 

 tion should be given to the artificial spreading of entomogenous 

 fumn and to more efficient ways of increasing their use. 



INSECTS IX RELATION TO REPRODUCTION OF FUNGI 



It has long been known that insects carry pollen and that the 

 setting of seed and the development of certain fruits, for example, 

 clovers, apples, and peaches, is conditioned by insect pollination. 

 Similarly insects disperse reproductive elements (spermatia) 

 among fungi. In support of this conclusion, Brodie (1931 ) found 

 that flies are agents of diploidization of Coprimts lagopi/s, a hetero- 

 thallic species. The fruit bodies of this mushroom do not form 

 unless oidia from the plus mycelium are transported to the minus 



