CHAPTER IV 

 MOTH GALLS 



GALLS caused by the presence of the larvae of lepidop- 

 terous insects are not common. The order Lepi- 

 doptera contains two sections — the Rhopaloura, or Butter- 

 flies (antennae clubbed, hind-wings without a frenulum), 

 and the Heterocera, or Moths (antennae variously shaped ; 

 rarely clubbed, but when they are, the frenulum is present). 

 No butterflies give rise to galls, and but few moths cause 

 what may be considered true galls. The life-cycle consists 

 of four stages — egg, larva, pupa, and imago. The eggs are 

 laid on the plants on which the larvae feed. The larvae — 

 usually spoken of as caterpillars — are worm-like creatures 

 with a head and thirteen segments. The first three seg- 

 ments are thoracic, and each carries a pair of short limbs. 

 Two, three, or more of the abdominal segments adjacent to 

 the thoracic are legless, but some of the posterior ones have 

 abdominal feet. The termination of the body carries a pair 

 of thick legs, of somewhat different shape to the abdominal 

 feet, known as " claspers." The larvae are mostly vegetable 

 feeders, deriving nourishment from the fluid part of the 

 plant, the solid part passing from the alimentary canal in dry 

 (usually) pellets, called " frass," Prolonged larval state, so 

 frequently seen in the Coleoptera, is rare amongst the 

 Lepidoptera, but the pupal state frequently lasts nine months. 

 The pupa or chrysalis is remarkable in its outer skin form- 

 ing a hard chitinous shell. 



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