CATALOGUE OF INSECTS. 11 



the middle. The omnipresent potato beetle may serve as an example 

 of this order, and also as an indication that the larval as well as 

 adult stages of the Coleoptera may be and usually are injurious. 

 The transformation is complete. 



The third and last of the mandibulate series is that in which all the 

 thoracic rings are joined together, the first segment or prothorax 

 becoming much reduced in size. The head is now free from the 

 thorax and united to it only by a slender neck. A fly, a bee or a 

 butterfly will at once show what this neck is like, if only casually 

 examined. 



The ancestry of this series began in aquatic forms passing the larval 

 stages under water, and the Ephemerida or day flies are probably the 

 earliest of the types. These insects pass their larval life under water 

 in the mud, in immense numbers, and when full-grown change to a 

 frail, gossamer-winged creature that is called a day fly because of its 

 very brief or ephemeral life. It appears in the early evening, seeks a 

 mate, deposits its eggs if a female, and dies before morning. Most 

 of the species have slender anal filaments, and when at rest hold the 

 wings upright like butterflies. The metamorphosis is incomplete and 

 the insects are of no importance to the farmer. 



The Odonata or dragon flies are also aquatic in the larval stage, 

 and in their day were very numerous and well developed. Among 

 our fossil species are some in which the wings expanded from 15 to 

 18 inches or even more, and there was at that time a reason why 

 primitive man should fear the ' ' devil's darning-needles. ' ' They have 

 two pairs of similar wings which are net- veined and they are predatory 

 in habit. The larvae live in the mud in ponds and among water 

 plants, feeding upon any soft-bodied creature that comes in their way. 

 The transformations are incomplete and the order is a peculiar one, 

 forming the end of a line which has no descendants. 



The Ephemerida, however, did develop in two ways— one to a 

 caterpillar-like larva living in mud and moist places generally, the 

 other toward a caterpillar-like larva living in the water and building 

 a tube or case for protection. The latter are the Trichoptera or 

 " caddice flies," the wings of the adults covered with hair, the 

 hinder pair folded under the anterior. The larvae are predatory in 

 some cases, vegetarians in others ; but in neither instance important 

 to the agriculturist. Their cases are made of sticks, stones or other 

 fragments and some of them are beautifully done, resembling shells 

 so closely as to deceive even collectors at first sight. The adults 

 usually fly at night, are attracted to light and have very long, slender 

 antennae. 



