258 EXPERIMENT STATION RECORD. 



that time, is said to have appeared in June, 1909, as a pest in experimental 

 wheat plats at the station. During the season of 1910, it appeared in slightly in- 

 creased numbers, but during 1912, only an occasional mined leaf was to be 

 found- 



During the larval stage this insect is a true miner, feeding upon the mesophyll 

 of the leaf. So far as has been observed the upper leaves only are affected and 

 the larva as a rule confines its operations to the outer half of the leaf, the 

 tendency of the pest being to inhabit the distal portion. After the leaf is 

 mined the dermis on both sides becomes brown and dry, thus resulting in the 

 injured area becoming functionless. At present the insect is not a serious 

 pest, as not over 15 to 20 per cent of the plants are affected, even during those 

 years when it has been most plentiful. 



The eggs are deposited in tunnel-like incisions extending lengthwise of the 

 leaf. On June 13, the earliest date uiwn which egg laying was observed, a 

 few mines were found which contained partially grown larvae. Under normal 

 field conditions 4 dnys are required for the incubation of the egg. Upon hatch- 

 ing out the larvae at once begin feeding and continue mining in an almost 

 straight line toward the tip of the leaf, gradually enlarging the tunnel laterally 

 as the increasing size of its body demands. From 7 to 9 days are required 

 for the development of the larvae. Upon completion of its growth the larvae 

 bursts a slit in the upper leaf surface, and, escaping, falls to the ground, and 

 burrows down to a depth of about 2 in., where the puparium is soon formed. 

 It is thought quite probable that there are 2 annual broods. 



In addition to occurring in wheat, the author has observed the insect ovi- 

 positing in timothy leaves and also has found rye and barley leaves bearing 

 the characteristic mines and larvfe. 



Chilocorus similis and its relation to scale insects in Japan, S. Nabl&.yama 

 (Mo. Bui. Com. Hort. Cal., 1 {1912), No. 13, pp' 932-936, fig. i).— There are 2 

 generations of this beetle each year. A few days after emerging from hiberna- 

 tion, which is passed under dead leaves or in the cracks of bark, eggs are de- 

 posited under scales. Usually one is laid under each scale, but there may be 

 often 2 and sometimes H under a single scale. The eggs are also deposited 

 under bark or between cracks, wherever a suitable place is found. Records of 

 4 lady beetles show 14, 16, 17, and 18 eggs, respectively, to have been deposited 

 within a period of less than one month. The larvae molt 3 times before pupat- 

 ing. The adult lady beetle feeds upon scales by lifting the scale and pulling 

 out the body; the larva makes a hole in the scale, and then pulls the body 

 out through the hole, or pushes the head into it. 



The principal food of this lady beetle consists of scale insects, especially 

 the young; it very seldom feeds on aphids. In Japan it feeds upon the San 

 Jose scale, Pseudaonidia duplex, P. pwonice, the West Indian peach scale, and 

 Parlatoria proteus, the West Indian peach scale being preferred, with the San 

 Jos6 scale second. In the first stage the larva consumes but a few scales, on an 

 average 1 or 2 young scale insects, but in the fourth stage, it may eat more 

 than 50 scales a day. Most of the larvae eat from 700 to 800 scales during the 

 total larval period, and the adult lady beetle eats from 800 to 900, averaging 

 from 20 to 40 scales daUy. The length of life of the adult is said to be about 

 35 or 36 days. 



Potato flea beetle (Epitrix cucumeris), O. A- Johannsen {Maine Sta. Bui, 

 211, pp. 37-56, pi. 1, figs. 4). — Next to the Ck>lorado potato beetle, E. cucumeris 

 is the most destructive of the amiually recurring insects on the foliage of the 

 potato In Maine. In addition to Its direct injury, it is thought to be an active 

 agent In spreading early blight through carrying the spores from plant to plant 

 on its body. 



