296 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 104 



by Schreiner climbing shrubs and trees, where thej'- cut off the buds 

 or leaves and then carried them down the tree into their burrow. 



References to the peculiar habits of these beetles are scattered 

 throughout the European literature because then* promiscuous 

 pruning occasionally is done on crops, causing some damage. Schreiner 

 (1906, pp. 197-208) lists Euphorbia, Artemisia, Plantago, flax, turnip, 

 wheat, buckwheat, young sunflowers, rape, hemp, dill, dahlias, nar- 

 cissus, tulips, peonies, and shoots of fruit and forest trees among the 

 plants pruned by Lethrus apterus. Other species seem to have 

 similar habits. Reymond (1933, pp. 209-211) has discussed the 

 adult habits of Lethrus potanini, which he found in one place pruning a 

 species of Ephedra. The ravages of Lethrus cephalotes have been 

 briefly mentioned by Shipley (1887, p. 335) and Schwarz (1891, p. 484). 



According to the references cited above, adult activity, which is 

 often diurnal, occurs in March, April, and May. Each cylindrical 

 burrow made by the beetles is marked by a push-up and is about 15 

 to 30 cm. deep. Each burrow is occupied by a pair of beetles, the male 

 doing most of the above-ground foraging, bringing the cut leaves to 

 the burrow. According to Schreiner, Lethrus apterus packs the leaves 

 into the cell after the egg is laid. The egg is not deposited in the cell, 

 but is placed in a small cavity just beyond its termination. A dia- 

 gram of the burrow and the shape and position of the 6 or 8 oval 

 cells can be found in a recent booklet by von Lengerken (1952, opposite 

 p. 45). The habit of placing the egg in a cavity beyond the food 

 ceU not only occurs in the genus Lethrus but has been accredited to 

 Typhoeus (Minotaurus) by Fabre (1922, p. 93) and to Bolboceras by 

 the present writer. 



After the egg of Lethrus hatches, development was observed by 

 Schreiner to be very rapid. The larva became third instar in 3 to 3)2 

 weeks and emerged as an adult in another 3)2 to 4 weeks. This rapid 

 development seemed to me to be more typical of some of the Bolbo- 

 ceratini than it did of the Geotrupini. 



The habit of using living leaves is almost unique. Dawson (1922, 

 p. 196) noted a rather similar case in Geotrupes splendidus miarophagus 

 using fresh cut grass to provision the larval cells, and I have found 

 G. splendidus and Peltotrupes youngi using dead leaves for larval food. 

 However, the habit of Lethrus of climbing vegetation to procure its 

 larval food is not found in other groups. The oddly shaped asym- 

 metrical mandibles that the males use for their pruning are likewise 

 very characteristic. 



BIOLOGY OF THE BOLBOCERATINI 



The next tribe considered, the Bolboceratini, should perhaps 

 precede the Lethrini on a phylogenetic basis, but when considered on 

 a behavioristic basis its position is not important. The tribe varies 



