Coleoptera 221 



tinguish the present group, most of whose members are oval and 

 convex in form, of moderate or small size, usually highly coloured 

 and often metallic. Both the beetles and their grubs feed on leaves. 

 The grubs are fleshy and stout, with distinct head and legs and 

 swollen abdomen which often has an adhesive sucker-foot at the 

 tail-end (see fig. 69). They often cause great damage to farm-crops. 

 The family is distributed in all parts of the world. 



Tenebrionidss. — The Tenehrlonidie are a large family of beetles 

 varying much in shape. The feelers, inserted beneath the sides 

 of the head, with eleven segments, are thickened towards the tip, 

 or slightly saw-shaped. The mandibles are stout with a basal 

 tooth, and the first maxillz have four-segmented palps. The elytra 

 cover the hind-body w^hich has five visible sternites. The legs are 

 variable in form, but the front haunches are small and globular, 

 and their cavities closed behind ; the hind-feet have only four 

 segments, while the front and middle feet have five. The larvz 

 are elongate, hard-skinned, cylindrical grubs with short legs and 

 two prominences on the hindmost segment which serve as 

 additional feet. The "mealworn" or grub of Tenebrio molitor is well- 

 known for its ravages on stored flour. The beetles of this family 

 (see fig. 85) live usually in fungi, rotting wood, and such hidden 

 situations. One of the best known members is the true " black 

 beetle " — Blaps mucronata — often found in cellars. The family ranges 

 throughout the world. 



Lagriidae. —The LagriiJa are a small family related to the 

 Tenebrionid^ but differing in having the feelers threadlike, the 

 front haunches conical and prominent, and the last segment but 

 one of each foot bilobed with a dense hairy coating beneath. The 

 legs are long and slender, and the number of foot-segments is as 

 in the Tenebrionidz. The beetles of this family have a short 

 hairy (pilose) coating. The larvz have comparatively long legs, 

 and their segments often bear tufts of hairs. The family is 

 generally distributed, but scarce in cooler regions ; only one species 

 occurs in the British Isles. 



Cistelidae. — The CistdiJa: are another small family related to 

 the Tenebrionids ; they differ from that family, as also from the 

 Lagriidz, in having the foot-claws toothed, while they agree with 

 both the preceding families in their front coxal cavities being 

 closed. The family is distributed in all parts of the world. 



Melandryidae. — The Mdandryld^ are a large family, agreeing 

 with the three preceding in the number of tarsal segments, but 

 differing from them in having the front coxal cavities open behind. 

 The head, which is not narrowed behind, is hidden by the thorax 

 as far forward as the eyes. The pronotum is as broad, or nearly as 

 broad, as the elytra, which cover the hind-body with its five 

 visible sternites. The legs are usually long and slender, the front 

 haunches globular. The larvse are elongate and cylindrical, with 

 chitinised head, thorax, and tail-segment, the rest of the body 



