474 



The average duration of the incubation period in summer is about 

 15 days, and that of the larval period during the same season about 

 13 days. The duration of the pupal stage of the worker in the summer 

 averages 13 days and that of the male 22 days. 



Heavy rains and floods, in addition to acting as factors in dispersal 

 in that they cause the floating of logs, etc., containing nests, act to a 

 certain degree as controlling agencies, especially during cold weather, 

 when the ants are in a more or less dormant condition. Artificial 

 barriers for outdoor use take the form of sticky bands round trees, 

 beehive stands, etc. The addition of 5 per cent, of carbolised oil to the 

 substance ordinarily used for coating flypapers prevents the growth of 

 moulds on the surface of the band in wet weather. The addition of 

 bichloride of mercury or nicotine sulphate prolongs the effectiveness 

 of the adhesive. In infested houses, tables, refrigerators, etc., may be 

 protected by placing the legs in saucers filled with naphthaline or coal 

 oil, or by banding the legs with tape saturated with bichloride of 

 mercury. An attractive poisoned bait, which has proved satisfactory, 

 consists of : — 15 lb. granulated sugar, 8 pts. water, | oz, tartaric acid, 

 f oz. sodium arsenite, 1| lb. honey. This bait proved attractive at 

 all seasons of the year. When placed in suitable containers outside 

 houses, ants ceased to invade the latter and were found in large 

 numbers visiting the bait. Parafiin-covered paper bags containing 

 a small quantity of the syrup and a piece of sponge were found very 

 satisfactory for using on trees. The extended use of this poison is 

 recommended. Hibernating ants in rural districts may be attracted 

 to trap boxes filled with decaying vegetation, which can then be 

 fumigated with carbon bisulphide. 



Ehrhorn (E. M.). Division of Entomology : Annual Report for 1915. 



— Hawaiian Forester and Agriculturist, Honolulu, xiii, no. 7, 

 July 1916, pp. 240-242. [Received 19th September 1916.] 



The work of the division included the inspection of imported plants, 

 fruits, etc., and the breeding and hberation of parasites of important 

 insect pests. The following parasites of the fruit-fly were liberated : — 

 Opius humilis, Diachasma fullawayi, D. tryoni, Tetrastichus giffardi, 

 Dirhinus gijfardi and Galesus silvestrii. Parasites of the horn-fly, 

 stable-fly and house-fly which were Hberated, included Muscidifurax 

 vorax, an undetermined African Spalangia, an undetermined Philippine 

 Spalangia, and an undetermined Philippine Pteromahd. Efforts were 

 made to obtain parasites of Dacus cucurbitae (melon fly). 



Paralipsa modesta (rice moth) was observed on a few occasions in 

 beans from Japan. 



Ehrhorn (E. M ). Report of the Division of Entomology for June.— 



Hawaiian Forester and Agriculturist, Honolulu, xiii, no. 7, July 

 1916, pp. 243-246. [Received 19th September 1916.] 



The following pests were intercepted : — Red spider on hydrangea ; 

 Aphids on roses and hydrangea from California ; red spider on roses 

 from California ; Aphids on bulbs of gladiolus. 



Parasites of Ceratitis capitata and Opius Jletcheri, a parasite of the 

 melon fly [Dacus cucurbitae], were liberated. 



