183 



active throughout the year, and there are usually about seven full 

 generations annually ; six from April to November, and one from 

 December to March. Hibernation does not occur. The life-cycle 

 from egg to adult averages 28 days. The adults appear on maize 

 in the field as soon as it reaches the roasting-ear Stage. When the 

 grain has become firm, eggs are deposited in all parts of it accessible 

 to the weevil. In shelled maize the majority of eggs are deposited 

 in the soft germ ; in the field damaged or poorly developed shucks 

 are preferred. In warm weather about 8 to 10 eggs are laid per day. 

 The rate of oviposition decreases in cold weather, and as the weevils 

 get older. The maximum number laid by one female was 576 during 

 149 days. The eggs hatch in from three to five days, but all stages 

 are prolonged in cold weather. There are four larval instars, each 

 lasting on an average four days. Pupation lasts five days, but during 

 the winter the adults may remain a month in the grain before emerging. 

 The average length of life of the adults is from three to six months. 

 The predaceous mite, Pedicidoides ventricosus, Newp., attacks all 

 immature stages of C. oryzae, which is also parasitised by the 

 Hymenoptera, Cercocephala elegans, Westw., Aplastomorpha vandinei, 

 Tuck. {Neocatolaccus australiensis, Gir.), Catolaccus incertus, Ashm., 

 Meraporus requisitus, Tuck., M. calandrae. How., and M. ntibilis. 

 Tuck., the last two being stated by Gahan to be identical with 

 Lariophagus distinguendus, Foerst. 



WiLLARD (H. F.). Opius fietcheri as a Parasite of the Melon Fly in 

 Hawaii. — Jl. Agric. Res., Washington, D.C., xx, no. 6, 15th 

 December 1920, pp. 423-438, 13 figs. 



The activities of Opius fietcheri, Silv., since its introduction into 

 Hawaii as a parasite of Dacus {Bactrocera) cucurbitae, Coq., in 1916, 

 are recorded [R. A.E., A, v, 2 ; viii, 347, etc.], and the biology of the 

 parasite is described. The physiology and anatomy of the various 

 stages are extensively dealt with. 



Cotton (R. T.). Tamarind Pod Borer, Sitophilus linearis (Hbst.). — 

 Jl. Agric. Res., Washington, D.C., xx, no. 6, 15th December 

 1920, pp. 439-446, 1 plate. 



The immature stages of Calandra {Sitophilus) linearis, Hbst., are 

 described. This Curculionid is very abundant in southern Florida, 

 and undoubtedly occurs wherever the tamarind ( Tamarindus indica) 

 is grown. As the food-plant grows only in tropical or sub-tropical 

 climates, the activities of the insect are not interrupted by winter. 

 The injury is confined to the seed pods. The adults enter the pod 

 at the stem end, in which cracks commonly occur owing to the swaying 

 of the pod. They then bore through the pulp into the seed, making 

 a cylindrical cavity in which from 1 2 to 50 eggs are laid. This operation 

 requires from one to two weeks, and as the eggs hatch in three days, 

 the first larvae appear before the last egg is laid. The oviposition 

 period lasts about 84 days, during which time about 180 eggs may be 

 deposited. The larvae begin at once to feed and bore in the seed. 

 The burrows radiate from the egg-cavity to all parts of the seed, 

 but the shell is never broken through. There are four larval stages, 

 covering from 12 to 14 days. Tire prepupal stage lasts one day, 

 and pupation about seven days. The adults remain within the seed, 



