16 



beginning of July ; these were soon joined by hosts of undeveloped 

 specimens which had eaten up all the available food in the neighbour- 

 hood and were seeking other feeding grounds. They were to be found 

 everywhere and seemed to have a preference for travelling along the 

 railways, causing much delay and expense, and were even a source 

 of great danger. The railway authorities at McCloud at first stationed 

 men with brooms on the fronts of the engines ; this was fairly successful 

 at first, but later was less so, as many of the caterpillars were inevitably 

 crushed in the process. Cresol sprinkled along the sides of the road 

 bed only retarded the migrating hosts for a few moments. Ditches 

 dug about camps kept out the pests, but could not, owing to expense, 

 be used by the railroad. At last an attachment was devised whereby 

 steam could be conducted from the engine through tubes and blown 

 forward along the track, ahead of the train. This was very successful 

 because it cleared the rails without crushing the caterpillars and at the 

 same time stunned or killed them so that they could not return. 



Though primarily feeding on the two species of Ceanothus, the cater- 

 pillars, when once they had consumed all their normal food, attacked 

 almost anything, though no coniferous trees seem to have been touched. 

 By the second week of July the caterpillars were commencing to 

 spin their cocoons ; from cocoons collected in the bush, moths emerged 

 between the 2'ith and 30tli July. Many of the caterpillars had been 

 parasitised by various Tachinids which could be seen in infested areas, 

 but they made but little impression on the numbers. From thirty- 

 eight cocoons collected twenty moths and three Ichneumonids were 

 reared, and several Tachinid puparia obtained. The predaceous 

 beetles, Calosoma semilaeva, Lee, and C. luxatum, Say, var. zimmer- 

 manni, Lee, were fairly numerous in the field and a Sphegid and a 

 large species of Psatnmophila were observed carrying off full-grown 

 caterpillars. Neither birds not ants attacked the living caterpillars, 

 although many dead specimens were carried off by the latter. 



Insect Notes. — Mtlilij. Bull. Cal. State Cotnmiss. Hortic, Sacramento, 

 iii, no. 9, September 1914, p. 378. 



The Sphingid, Phohis achemon, has been doing considerable damage 

 to grapes, entire defoliation of about 40 acres and serious damage over 

 a much larger area being reported. A number of the Braconid, 

 Apanteles glomeratus, has been introduced into cabbage fields infested 

 with the caterpillars of Pieris rapae. Numerous adults of the California 

 grape-root worm, Adoxus obscurus, L., were found feeding on Saxifraga 

 feltata, which occurs very abundantly along streams in the Sierra 

 Nevadas. Adults of the large wood-boring beetle, Priomis californicus, 

 have been collected, and the pine scales, Aspidiotus californica and 

 Chionaspis pinifoliae, were numerous on pines. The mealy plum louse, 

 Hyaloptenis arundinis, has been found feeding on reed grass, Phrag- 

 tnites communis, this being the first record of any food-plant other 

 than the plum in California. H. arundinis has been known to leave 

 plum and prune trees as soon as it becomes winged, but whither it 

 migrated was unknown. In Colorado, Gillette discovered its habit 

 of going from the plum to the reed grass some years ago, but as this 

 grass is not plentiful in California it would appear that this Aphid 

 must also have some other alternate host. 



