LFST OF ILLUSTRATIONS. 



100. 

 101. 



103. 



104. 

 105. 



106. 



107. 



lOS. 



109. 

 110. 



111. 



1 1 •_'. 



Markings of Scolytus de- 

 ■striir/oi- in bark of Eng- 

 lish elm . . . 'J4 

 Showing exit-holes of same 94 

 Scolytus destructor . . 95 

 Markings of Scolytus pruni 



in branch of apple . 96 

 Markings of Scolytusmulti- 



striatus in bark of elm . 96 

 Markings of Scolytus intri- 



catus on oak pole . 97 



Scolytus intricatus . . 97 



Markings of Hylasles pal- 



liafus .... 100 

 Hylastes pcdliatiis . .100 



Markings of Hylvsinus 



crenatus . . .102 



Hylesinus crenatus . .103 



Markings of Hyltsiiius 



fraxini . . .104 



Hylesinus fraxini . .105 



Markings of Hylesinus 



oleiperda . . .105 



Hyhslnus oleiperda . . 106 



Markings of Hylesinus 



rittcdtis . . .106 



Hylesinus vittatus . .107 



Shoot of Scots pine show- 

 ing the entrance-hole 

 and boring of a pine 

 beetle. . . .108 



Showing mother and larval 

 galleries in process of 

 formation . . .108 



Portion of bark of Scots 

 pine, showing two 

 mother - galleries and 

 larval workings of pine 

 beetle. . . .109 



Hylmrjus piniperda . 110 



SAavkmgsoiP/daophthorus 



7'hododacfylus on gorse . 113 

 M arkings oi Phkeophthoriis 



rhododactylus on broom 113 

 Phkvophthorus rhododac- 

 tylus . . ... 1 1 4 

 Markings of Cryphalus 



abietis . . .117 



Cryphalus ahietis . . 117 



Showing "exit-holes" of 



Cryphalus tilue . . 118 



Markings of CryphalnK 



tilia; on lime . . 118 



Maikingsof Cryphalusfa(ji 118 



113. 

 114. 



115. 

 116. 

 117. 

 118. 



120. 



121. 

 122. 



124. 

 125. 



126. 



127. 

 128. 



Xylocleptes bispinus . 

 Mother -gallery of JJryo- 



ca4es villosus 

 Dryocd'-tes villosus . 

 Dryocoites alni 

 Tomicus sexdentatus 

 Markings of Tomicus acu- 



minatus 

 Markings of Pityo(jenes 



hidentatns (initial stage) 

 Fully developed markings 



of Pityogenes bidentatus 

 Pityogenes bidentatus 

 Block of wood shown in 



perspective to illustrate 



the workings of the 



genus Trypodendron 

 Workings of Trypodendron 



lineatum 

 Trypodendron lineatum . 

 Markings of Trypodendron 



do^neslicwm . 

 Xylehorus dispar (male) . 

 Xyleborus dispar (female) 

 Burrows of Xyleborus 



dispar 



120 

 120 

 121 

 121 



122 



123 



123 

 124 



125 



126 

 126 



127 

 128 

 128 



HYMENOPTERA (Oak-Galls) 



