180 



in-lir.e operation. Each process, except shearing, is performed at the rate of 

 ca. 300 trays/h. The yield of weevils averages between 30 and 40 percent of 



eggs ti'.at hatch when placed on the diet at the rates of 200 to 300 eggs/300 



2 

 cm . In 1 h of operation, the machine replaces $93.75 worth of plastic petri 



dishes for $21.25, thus reducing the cost of rearing containers by ca. 75 per- 

 cent. Substantial additional savings may be expected because the need for 

 separate functions to fill the trays with diet, egging, and sanding was eliminated. 



348. Harris, F. A.; Lloyd, E. P.; and Baker, D. N. 1966. Effects of the fall 

 environment on the boll weevil in northeast Mississippi. J. Econ. 

 ■ Entomol. 59: 1327-1330. 

 Limited studies of the preoviposition and developmental periods of the 

 boll weevil, Anthonomus g randis Boheman, were made in the field in the fall 

 of 1964. More extensive studies were made with simulated fall temperatures 

 and day lengths in the laboratory during the winter 1964-65. Both field 

 and laboratory data indicated that with the cooler temperatures of the fall, 

 the preoviposition period of emerging boll weevils was generally longer 

 than that of weevils emerging earlier in the season, though some individual 

 females had a preoviposition period shorter than 1 week until night tempera- 

 tures dropped to 50"? or lower. Each developmental stage of the boll weevil 

 was considerably longer, with cooler temperatures and shorter photoperiods. 

 The total developmental period from egg to adult was as short as 24 days 

 when eggs were laid in squares early in September and as long as 60 days 

 when eggs were laid in bolls in mid-September. The time to emergence of 

 adult boll weevils from eggs deposited on a given date in the fall showed 

 a wide range. The data indicated that an egg laid on or after October 1 

 would not contribute to the overwintered population of weevils. 



