ENTOMOLOGY 129 



evident after harvesting the crop, to dip young plants in an insecti- 

 cide before planting, and to produce the maximum vigor and health 

 of the plants by thorough cultivation and fertilization. In the 

 question of the control of the insect pests and diseases of plants, no 

 one point is more important than vigorous and clean cultivation and 

 the proper supply of plant food and moisture. It is an accepted 

 fact in applied entomology that a healthy growing plant is capable 

 of offering resistance to the attack of an insect pest. (Press Bui. 10, 

 Hawaii Agr. Exp. Sta.) 



The Mango Weevil. The destructive work of the mango weevil 

 in the seeds of mangoes was noted in Hawaii for the first time last 

 year. The nature of the insect and its injury point it out to all 

 persons interested in the culture of the mango as a serious pest. 



As a beetle, the mango weevil has a thick pair of wing-covers 

 which, when folded together at rest, give the body the appearance of 

 a shell. The wing-covers are much rounded and extremely hard. 

 As a weevil, the head is prolonged in front into a beak or rostrum, 

 bearing the antennaB on Us sides and the modified mouth-parts at the 

 extreme end. The mouth-parts are formed for gnawing. In the 

 mango weevil, the beak is short and thick and when at rest is turned 

 back beneath the thorax in a groove terminating between the first 

 pair of legs. The adult weevil varied from % of an inch to 5-16 

 of an inch in length in the specimens measured. When newly de- 

 veloped, the adult is a whitish pink in color, but soon changes to a 

 dark brown with yellowish markings. 



The beetle feigns death on being disturbed and drops to the 

 ground with the head drawn well under the thorax and the legs 

 folded beneath the body. Its protective resemblance to coarse earth 

 and debris is particularly noticeable. Nothing has been observed 

 in regard to the food habits of the adult. 



The eggs of the mango weevil were found on mangoes from 

 one-half to three-fourths fully grown, situated alongside a slight 

 incision on the rind. The writer has not observed egg-laying or 

 carefully noted the habits of the weevil as regards oviposition, but 

 is inclined to think that the eggs in the instances seen were probably 

 placed within the incision or cavity and later forced out by the exuda- 

 tion of juice, an amount of which in a dried condition enveloped 

 them. 



The larvae in appearance are, generally speaking, like the sugar- 

 cane borer, that is, footless, "fleshy" grubs, light in color, with a 

 dark head. The entire development after hatching from the egg is 

 undergone within the seed. When fully developed, the larva con- 

 structs a pupal cell, surrounded simply by the excrement, within the 

 tunnel formed by feeding, and transforms to the pupa. The inac- 

 tive pupa is perfectly white in color with the developing head, legs, 

 wings and body-parts plainly indicated. 



Since the mango weevil is a special feeder on the seed of the 

 mango, its numbers in any particular season are in direct propor- 

 tion to the size of the mango crop for that season. That is, when 

 the mangoes are abundant, the brood of weevils arising from the 



