300 Fiftieth Eeport. ox the State Museum 



Leptodesmus sp. ? 

 Thfliijand-leggcd Worm Infesting Green-houses. 

 (Class Myriapoda : Ord. Chilognatha : Fam. Polydesmid^.) 



A gentleman in charge of some private greenhouses in Kansas City 

 made complaint of " a pestiferous, repulsive pest" which is proving very 

 injurious, and which it has not been possible to control. Accompanying 

 the specimens sent he has written : 



We have used ammonia — one tablespoonful to four quarts of water, 

 soapsuds, and slacked lime. We have taken off the pots from the benches 

 in this particular house and covered them with powdered lime — then 

 put on two inches of cinders and replaced the pots, and still the worms 

 come, lying under each pot on top of the cinders. The benches were also 

 cleaned and flooded with boihng water, and even steamed with a hose 

 attachmeat. Can you tell me what the species is and how to eradicate 

 it ? One of the greenhouses contains three beds of earth that was mixed 

 with sheep manure from stock yards here, by a florist employed. They 

 are eve'-ywhere \\\ this house, and nearly everything planted in beds is 

 dead or dying; but begonias, geraniums, colias, heliotrope, etc., in pots, 

 are doing well in spite of the pests sticking to the bottom of the pots." 



The greenhouse pest of the above communication proves to be, upon 

 examination of the specimens sent, one of the numerous species of " thous- 

 and-legged worms" that occur in the United States. Those that usually 

 come under observation have rounded, cylindrical bodies, as seen in the 

 family fulidas. Those received, are flattened and spreading out at the 

 sides, wliere the numerous short legs with which they are furnished have 

 so lie whit the appearance of a fringe (PI. XV, fig. i). 



Description of the Millepeds. 

 Most of them are about three-quarters of an inch long, of a reddish- 

 broivn color, and are apparently full-grown, while others are about one- 

 half inch in length and whitish. The head bears six-jointed attennae 

 sparsely clothed with coarse setae (PI. XV, fig. 3), and the body of the 

 male 30 pairs of legs, — a pair on the first, second, fourth, and seventh, 

 and two pairs on the fifth, sixth, and eighth to the eighteenth segments 

 inclusive ; the last two segments legless (apodal); the female has 31 pairs 

 of legs, there being two pairs on the seventh segment ; the hinder angles 

 of the segments are acute. Repugnatorial pores surrounded by slight 

 swellings occur on segments 5, 7, 9, 10, 12, 13, 15-19 inclusive. The 

 smooth convex dorsal plates with only a slight transverse sulcus are 

 characters of the genus Leptodesmus, to which this form is referred. At 

 the bottoai of the transverse sulcus there is a minute tuberculate ridge. 



