1900] BEAN AND PEA- SEED BEETLES. 27 



very similai*,''' and the following short notes of method of attack of the 

 Bean-seed Beetle, B. rufimanus, though well known, may save trouble 

 in reference. 



The method of attack is for the beetle (which is furnished with ample 

 wings) to fly to the blossoming Beans, and to lay its eggs on the 

 young seed-vessel in the centre of the flower whilst it is still so small 

 that it can hardly be called a pod. From these eggs the little maggots 

 soon hatch and make their way into the growing seed in the young 

 pods. Each maggot gnaws a gallery into the seed, and possibly there 

 may be more than one tunnel ; but in its tunnel each maggot (in the 

 dirt and rubbish consequent on its feeding during its own growth up 

 to maturity in the growing Broad Bean) turns to chrysalis, and from 

 this to the beetle state (see figs. 3-7, p. 21). But before it changes 

 from the active maggot condition to that of the quiet chrysalis, it 

 (customarily) gnaws its gallery right up to the skin of the Bean, but 

 not through it, so that the circular bit of skin remains at the end of 

 the burrow uudetached, but just sinking in a little from the substance 

 of the Bean having been removed behind it ; and when the tenant has 

 passed to beetle state, and it is time for it to go forth from the full- 

 grown ripened seed and fly abroad, it has only to press out the door, 

 so to call it, of its burrow, and become free. 



The maygots are fleshy, wrinkled across, and with a small horny, 

 rusty-coloured head, and so far as I am aware, in the case of this kind, 

 always legless. 



With the larvae of the Pea-seed Weevil, B. pisonim, L., the case is 

 somewhat different, in respect of it possessing three pairs of " false 

 legs " on the fore part of the body in its quite early life — that is, one 

 pair on each of the three segments next to the head ; and also, if cir- 

 cumstances should not suit the maggot for boring into the Pea seed 

 immediately on hatching, that it sometimes lives as a miner for a 

 while in the inside of the pod. 



A description of these six " post-embryonic " legs, with much 

 magnified figure showing them in the case of the larva of B./abce, Eiley, 

 which may be taken as showing this peculiar structure also m the case 

 of the larvcB of B.pisorum, will be found in ' Insect Life." f And at p. 392 

 of the same work will be found mentioned that the newly-hatched larvae 

 of B. pisi ( = pisorum) have almost the same characteristics as those 

 described in this case (see reference in note), that is, of the Bean-seed 

 Beetle of America, | excepting that the three pairs of legs of the Pea- 

 seed grubs are somewhat shorter and stouter. In both cases the small 



* A slight difference in structure of the larva of B. pisorum in its early condition 

 has been found to exist. (See above.) 



t See ' Insect Life,' vol. iv. pp. 300, 301. 



\ B. fahcE, Eiley, now known as B. obtectus, Say. 



