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TWENTY-EIGHTH FRUIT -GROWERS' CONVENTION. 



exhibit more or less of some species of these lilliputs. Again, they are 

 very long and slim, and many — most, when mature — have very long, 

 slender, fringed wings. When not in use these wings lie flat on the 

 back of the insect, so that the slender form is still maintained. The 

 first stage, or larva, is quite like the last, or imago, except there are no 

 wings. The pupa looks like both the larva and the imago, but curiously 

 enough is inactive. The head is nearly square; sometimes longer than 

 broad, and in other species the reverse is true. The compound eyes are 

 as usual, and the three usually placed ocelli are often present. The 

 antennae are prominent, and from six to nine jointed in the adults, 

 though fewer jointed in the larva. Our species, which the authorities 

 at Washington pronounce Euthrips tritici, but which to me seems nearer 

 E. occidentalism if the two are not varieties of the same species, shows 

 eight joints in the adult and only four in the larva. The relative 

 lengths of the joints and the hairs on them are of specific importance. 



The mouth organs, while structurally mandibulate, that is, fitted for 

 biting, are functionally suctatorial, or haustellate, that is, fitted to pierce 

 and suck. We see, then, why the wound to the orange peel is so slight. 

 The insect is very tiny, the mouth organs exceedingly diminutive, and 

 so in their puncture and sucking the merest trace of injury is wrought. 

 No wonder the wound is so obscure. No wonder that it heals entirely 

 when the fruit remains on the tree. 



The thorax is not especially peculiar, though its appendages, the legs 

 and wings, are greatly different from the same in all other insects. The 

 six feet all end in a sort of bladder, or sack, which functions, in lieu of 

 the usual claws, to hold the insect to leaf or twig. These sacks can be 

 drawn in or pushed out by blood pressure, which is always done as the 

 foot is set down for use. This fact gives rise to the name Physopoda, 

 which is sometimes applied to these insects. The word means bladder- 

 foot. The wings are equally peculiar. They are long, slender, with 

 very few veins, and beautifully fringed. The fringe gives added spread 

 with little added weight. The form, veins, and extent of fringe of the 

 wings aid to determine the separate families, of which there are three. 

 The abdomen shows ten joints. Its form, the hairs which it bears, and 

 the presence or absence of ovipositor are of value in classification. 



Order Thysanoptera. — The great Linnaeus placed all these insects in 

 the genus Thrips, hence this word is singular as well as plural, and 

 always refers to this peculiar type of insect. We still have the genus 

 Thrips, family Thripidse, and the word thrips with various prefixes, to 

 designate several genera. Linnaeus placed these with the bugs, lice ? 

 aphids, scale insects, etc., in the order Hemiptera. True they are 

 sucking insects, but the wings, the mouth organs, and transformation 

 are all utterly different from the same in all the great bug group. For 

 this reason, all entomologists now wisely separate them from the 



