44 HITINO AN'I) NOXIOl'S INSKCTS OTHER THAN MOSQUITOES 



The Lmly-binis — Coccinelliilir — live on Apliiils ami (!occiils, an<l tliemsi'lvcs iiicrefise to 

 such an extent as to lie in many years a conspicuous part of the insect wurjil. Crowds of 

 the hirvui of lleiiu-roliiiilit antl Si/r/i/iith are constantly engageil in spearing and sucking the 

 Aphides. Hence tlx- old naturalist RoniU't said that, "just as we sow grain for oiir lienefit, 

 Nature has sown Aphids for the henetit of multitudes of ditVerent insects. " He might have 

 adijcd that these difierent insects are for the benefit of iiimu, it being clear that without them 

 the population nf tile world must rapidly decrease." A short and simpler account given by 

 Theobald* may also be i|Uoted. He says: "They" (the Aphidie) "live entirelv upon the 

 sap of plants, which they draw from the leaves, stem, and even roots." After mentioning the 

 "cornicles "or "honey-tubes" and the waxy substance on the skin, he continues: — "Winged 

 and wingless females occur, the males being also often winged. I'artheuogenetic reproduction 

 takes place ; both ovii)arous and viviparous females arc found in all .sjieeies. The wingless 

 forms are generally asexual, and so are the summer winged females. Ova are usually laiil 

 only in the autumn bv the oviparous female after fertilization by the male. , . The 



reproductive powers of these insects are enormous as well as ptiuliar. The wingless 

 female, starting in the spring, produces with great rajiidity living young without the 

 agency of a male; these asexually-produced young or lice, soon grow sulKeiently to start 

 reproducing again, and so on for eight or nine generations. As a rule, a plant becomes 

 smothered by these wingless forms; and in the summer sume send out little bud-like growths 

 from the thorax, rudinu'iifary wings, a pupal stage, and fiom these active pupie come forth 

 winged females, which Hy off' to other plants. These winged females are also viviparous, 

 and produce again asexually living young, and so on until the autumn when a third kind of 

 female appears — the oviparous female, and alsci a male. After the male has fertilized the 

 female aphis, she deposits a few eggs upon tiie plants, which remain over the winter. These 

 eggs mostly hatch out in the spring, Eut many also hibernate as (jueen or mother females 

 and commence to reproduce at once on the return of warm weather. There is often not much 

 difference between the young (larvu;) or lice, as they are called, and the viviparous female. 

 but larvie, pupa, and adult may generally be distinguished by variations in colour." 



In the light of these notes one must confess that very little is known about the Smlan 

 Dura Aphis. We are acquainted with the aiitnnnnil forms, and in the spring one has found 

 eggs and wingeil forms, but we do not know what hajipens to the insect when it leaves the 

 Dura plants. To tind out, careful field work would be reijuired, continued over a long 

 period. An iiphis has been found on melon plants, but I believe this to be a different species, 

 I have also found a very curious aphis on cotton, mounted specimens of which were submitted 



Apliis of to jIj. Theobald. It is totally different from tlic A/'/iis sDnjIii. I am inclined to agree with 



Major Dickinson that the cotton jdaiit is not liable to infestation by the latter. 



Another eonnnon but much less deadly enemy of the dura is a red //I'liiiji/cnm or plant 

 bug which attacks the grain seeds. Specimens of this pest have also been sent to 

 Mr. Theobald ((•(>//• p. 95). No doubt it reijuires the same treatment as does . I. vy/om/oyn/* 

 viilitfiliix, the bug of melons {viilc First Rcjiort). Some cotton pests have come under 

 notice, amongst them certain of the Ccrcop'ulai or Frog-hoppers and a tiny beetle. 



Both Mrs. Broun and myself bred out a Dipteron from certain larvje which caused 



A Melon Fly great damage to melons and were sent us by Mr. Durant. The fly could not be identiiied 

 here, but specimens of larvie, pupa?, and adult insects were sent to England, and Afr. Theobald 

 describes it fully on p. 93. 



* Agricultural Zoology, 1899, p. 237. 



