1889 



GLEANINGS IN BEE CULTURE. 



84? 



APHID^E-EQQS AND NO EGGS. 



ABE THEHE ANY INSECTS WHICH REPRODUCE 



THEIK SPECIES WITHOUT EGGS ? 



TN Gleanings of April 1st, page 265, Prof. Cook 

 iff has a short article on house-flies. In it he 

 W says; " House Hies do not breed in winter, and 

 "*■ all insects come from eggs." And, again, at 

 the close of the article he reiterates the latter 

 statement: "All insects come from eggs," and 

 adds: "Any observations that seem to contradict 

 these statements need to be repeated." 



I agree with him in regard to what he say s about 

 house-flies; but when he says that " M insects come 

 from eggs " it seems to me that that statement is a 

 little " too sweeping." I always had the idea that 

 they all came from eggs, until within the last year 

 or two, when my own personal observation forced 

 me to come to the conclusion that there must be 

 some exceptions to that rule. In studying the sub- 

 ject to find out what others thought, I found some 

 items which I think might prove as interesting to 

 others as they have to me. 



Here is an extract from Zell's Cyclopedia, in re- 

 gard to the particular family of insects which I 

 was studying. 



APHID.E. 



A family of hemipterous insects which have the 

 body short, and furnished at the hind extremity 

 with two little tubes, or pores, from which exude 

 minute drops of a very sweet fluid, called honey- 

 dew, which is eagerly sought after by ants. The 

 genus Aphis, or plant-lice, inhabit all kinds of 

 plants, the leaves and softer portions being often 

 completely covered with them. The Aphis hamuli, 

 or hop-fly. is in some years very destructive to the 

 crop; and it is to this cause that the variations of 

 the hop-crop, from year to year, are mainly due. 

 The young are hatched in the spring, and soon 

 come to maturity; and, what is remarkable, the 

 whole brood consists of wingless females; and, 

 what is still more remarkable, these females bring- 

 forth living- young, each female producing 15 or 20 

 in a day. These young are also wingless females, 

 and at maturity bring forth living young, which 

 are also all wingless females; and in this way brood 

 after brood is produced, even to the 14th genera- 

 tion, in a single season, and this without the ap- 

 pearance of a male. But the last brood in autumn 

 contains both males and females, which at length 

 have wings, pair, stock the plants with eggs, and 

 then perish. Reaumur has proved that a single 

 aphis, in five generations, may become the primo- 

 genitor of about six thousand millions of descend- 

 ants." 



Reaumur was a French philosopher, a member of 

 the Academy of Sciences, a distinguished inventor, 

 and the author of " Memoirs Illustrating the Histo- 

 ry of Insects." He died in 1757. According to this 

 account of the aphis, these insects are produced 

 from eggs, and also produce young in a living state ; 

 the latter more than the former, and in multitudes. 

 Those of us who have plants, and know from per- 

 sonal experience what a pest these " little var- 

 mints " are; how rapidly they increase, and how al- 

 most impossible it is to get rid of them, are quite 

 willing to believe that they do not wait to be hatch- 

 ed, but come in battalions, ready for work. You 

 can take a clean plant, one that you know is not in- 

 fested, and place half a dozen of these wingless fe- 

 males on it; then set it away where it will not come 

 in contact with other plants, and do not disturb it 

 for a few days. If you examine it in two or three 

 days I think you will be surprised at the swarms of 

 aphis, of various sizes, which you will find. If you 

 have the same experience we have had, you will 

 And them ranging in size from the smallest speci- 

 men imaginable, up to those fully grown. Look at 



your plant daily, and you will find young insects 

 the first day, and every day. 

 Ipava, 111. Anna B Quil-lin. 



The above was sent to Prof. Cook, who 

 replies as follows : 



At. I, INSECTS COME FROM EGGS. 



I have read Miss A. B. Quillin's interesting com- 

 munication, with no small interest. The tints 

 which she gives are indeed facts, but they do not 

 warrant her conclusions, as I will show. It will be 

 profitable right here to describe not only the three 

 kinds of sexual reproduction, but also the three 

 kinds of reproduction. 



The first kind of reproduction, called reproduc- 

 tion by fission, is simply division. The animal 

 breaks apart, and, presto! there are two animals in 

 lieu of one. This is the only reproduction in the 

 lowest branch of animals, like the curious amoeba 

 —the one-celled animals, or the protozoa. R« pro- 

 duction by fission is al60 confined to the lower 

 branches of the animal kingdom, though in all but 

 the protozoa it is attended with other kinds or 

 modes of increase. Thus, the beautiful fresh-water 

 hydra, though it reproduces by both the other 

 styles of reproduction, yet if, even byaccidetit.it 

 be cut in two, or even sliced up, each part becomes 

 a perfect animal. 



The second kind of reproduction is by gemma- 

 tion, or budding. A bud develops on the side of 

 the animal, finally drops off, and there is a second 

 animal. Gemmation is also confined to the lower 

 branches of animals. It is well illustrated in coral 

 animals, or polyps. It is always attended with 

 sexual reproduction, and sometimes with ti;sion. 



Sexual reproduction is reproduction from eggs. 

 Sometimes these eggs develop with no outside viv- 

 ifying influence. This is parthen< genesis, or aga- 

 mic reproduction — reproduction without males. 

 Usually the eggs must receive si erm-cells— must 

 be impregnated, or they come to naught. The eggs 

 are produced in special organs — ovaries — and the 

 sperm-cells in other special organs known as testes. 

 In some cases these two kinds of organs exist in 

 the same animal, and we call such an animal monoe- 

 cious, or a hermaphrodite. Usually— always among 

 insects and vertebrates — the sex organs are in dis- 

 tinct individuals, and we call such animals bisexu- 

 al, or dioecious. Even animals as high as snails 

 and angleworms are hermaphrodites. Often the 

 highest animals like some insects appear to be both 

 male and female. This, however, is only superfi- 

 cial. The animal is really either male or female. 



Now, while all higher life, even to man, comes 

 from eggs, this appears not to be the case; and it is 

 not strange that our good friend thought I had 

 overstated the matter. There are three kinds of 

 sexual animals. First, the oviparous. These ani- 

 mals lay eggs which develop outside the mother 

 animal, from nutriment contained mainly in the 

 egg substance. Most insects, fish, reptiles, and all 

 birds, are oviparous. 



Second, the ovoviviparous. These animals differ 

 from the oviparous only in that the eggs hatch in- 

 side the mother, and so the young are brought 

 forth alive, and not as eggs. The nutriment, us be- 

 fore, comes from the substance stored in the egg. 

 Here we find the plant-lice referred to, which are 

 also agamic, the sheep-ticks, several two-winged 

 Hies, sharks, and some snakes. 



Lastly we have viviparous animals, which in- 

 clude man and nearly all mammals— there are two 



