﻿STRAWBEEBY EOOTWORM ON GREENHOUSE EOSES 21 



•whicli forms the upper side of a longitudinal groove, the lower edge of which is 

 made up of the cosfe of the legs on the thoracic segments and a row of only 

 slightly prominent tubercles on the abdominal segments, one on each. Each 

 tubercle in this second row bears a bunch of from two to four setse. A trans- 

 verse ventral ridge is present on each abdominal segment and bears two 

 groups of short spines on each side of the ventrimeson. These form two 

 longitudinal rows along the abdomen. The medial gro,ups are each composed 

 of from S to 10 spines, except those on the last segment, which only have 4 or 

 5 spines, while the outer groups have from 4 to 6 spines. All the spines on the 

 abdominal ventral ridges arise at a sharp, acute angle from the body and point 

 backward. 



The head is smooth, somewhat flattened in front, and bears a few setse. 

 The clypeus is transverse, trapezoidal, narrowing forward, and the labrum 

 is rounded in front. The minute antennae are four-jointed, the outer angle 

 of the third joint being continued in a cylindrical process which reaches to 

 the end of the triangular fourth joint. The maxillae are moderately developed. 

 The cardinal and basal pieces are not well distinguished, the maxillary lobe 

 is armed with stout spines within, and the palpi are prominent and four-jointed 

 The labium is thick and semicircular, with little appearance of a palpigerous 

 tubercle. The labial palpi are slender, cylindrical, and unarticulated. The 

 bifid mandibles are dark brown with black tips, and therefore stand out in 

 marked contrast to the light-colored head and body. 



The legs are about as long as their corresponding segments and are white, 

 with the exception of the simple claws, which are dark brown at the tips. 

 There are a few setse on the legs, becoming short and spinelike toward the 

 claws. 



EAELY ACTIVITIES AND LOCATION IN THE SOIL 



That the newly emerged grubs are very active and have consider- 

 able vitality was demonstrated when five larvae were kept in a 

 small gelatine capsule with only the dried leaf bearing the empty 

 eggshells from which they hatched. They remained alive from 

 three to five days. 



The leaf (fig. 4) carrying the egg mass may drop or be washed 

 to the ground by the force of the sj^ringing water before the larvae 

 hatch, so that they may crawl off directly on the soil; but if the 

 leaf is still stuck to the twigs or stakes the larvae do not hesitate 

 to drop off. Newly hatched larvae have been placed on a piece of 

 pai^er and their course of travel traced. Their tortuous trail was 

 in every case made up of a series of loops, always to the right if 

 the little larva started that Avay, or to the left if the first turn was 

 to the left. One larva traveled a distance of approximately 36 

 inches in 63 minutes, at the end of which it was 4% inches in a 

 straight line from the starting point, having crossed its path 15 

 times, always turning to the right. These actions probably explain 

 why the larvae always bore their way into the soil with a spiral 

 motion. 



Presumably the larvae enter the ground (fig. 4) as soon as they 

 abandon the leaf on which they hatched. Larvae placed on the soil 

 of beds immediately after hatching entered the ground not more 

 than 2 inches from where they were first placed. Others put on 

 the soil of potted plants would bore into the first crevices or open- 

 ings which they encountered. Only in a very few instances were 

 these newly hatched larva; observed to remain on the soil surface 

 longer than 15 minutes. Some Jarvtc which were dropped on soil 

 from a height of 18 inches immediately worked their way into the 

 groimd, and 75 per cent of tlieiii were found alive three days later. 



The entire larval stage is spent in the soil (fig, 4), usually close 

 to the ball of roots of the rose plants. Ol'tcntinies larva; have been 



