THE GKAIN BUG. 



21 



imposed on a cylindrical cluster of eggs of the New Mexico range 

 caterpillar {HemUeuca olivias Ckll.) that had been deposited around 

 a sunflower stem. 



NUMBER OF EGGS IN EACH CLUSTER AND THEIR DISPOSITION. 



Counts were made of 185 typical o^gg clusters collected in the field 

 during 1915 and 1916. The number of eggs in individual clusters 

 varied from 13 to 43, the average being about 26. The smallest Qgg 

 cluster consisted of 9 eggs and the largest, apparently deposited by a 

 single female, consisted of 75 eggs. No uniformity was apparent in 

 the number of eggs composing each cluster. This is a deviation from 

 the published records, which indicate that in closely allied species 

 there exists a uniformity in the number of eggs in each cluster. 



The eggs are deposited with considerable regularity in two or four 

 parallel rows, each egg being placed in the alternate space between 

 the eggs of the adjoining row (see fig. 3), andeach row consisting of 

 from 7 to 20 eggs. This tendency is particularly marked when plant 

 stems or the awns of grain heads are selected for Qgg deposition. 

 Frequently when eggs are deposited on the broad surface of an ob- 

 ject the formation of the cluster is very irregular. 



NUMBER OF EGGS DEPOSITED BY EACH FEMALE. 



The females normally do not deposit their full complement of 

 eggs at one time or in a single cluster. Twenty-one newly matured 

 females collected in the field early in the season and placed in con- 

 finement deposited a maximum of 107 and a minimum of 9 eggs, the 

 average being 54 eggs from each female. These eggs were deposited 

 in from 1 to 10 clusters over periods extending from 1 to 16 days. 

 (See Table VI.) 



Table VI. — Ovipositicyii habits of confined females of Chlorochroa sayi. 



Female 



No. 



Total 

 number 

 of eggs. 



Number 

 of sepa- 

 rate 

 clusters. 



Number of eggs in each 

 cluster. 



Average 

 number 

 of eggs 

 In each 

 cluster. 



Days 

 between 

 first and 

 last ovi- 

 position. 



1 

 2 

 3 

 5 

 9 

 10 

 12 

 16 

 17 

 18 

 19 

 20 

 21 

 22 

 23 

 24 

 25 

 26 

 27 

 28 

 30 



91 

 66 

 32 

 60 

 62 

 43 

 107 

 11 

 16 

 58 

 55 

 56 

 53 

 9 

 67 

 97 

 43 

 61 

 43 

 71 

 43 



5 

 1 

 1 

 6 

 3 

 2 

 5 

 2 

 1 

 5 

 3 

 2 

 2 

 3 

 2 

 4 

 3 

 6 

 1 

 2 

 10 



53-3-7-14-14 



18.1 



56 



32 



10 . 



20.2 



2L5 



21.2 



5.5 

 16 

 11.3 

 18 

 28 

 26.5 



3 

 33.5 

 24.2 

 14.3 

 10.1 

 43 

 35.5 



4.3 



16 



56 



32 





3-4-6-44-1-2 / 



5 

 1 

 1 



10 

 2 



59-1-2 



4-39 



56-30-11-4-6 



8-3 



16 



43-2-4-7-2 



6 

 3 



11 

 3 

 4 

 2 



13 

 3 



11 



32-19-4 



28-28 



40-13 



3-3-3 



34-33 



46-13-12-26 



2-26-15 



16-9-33-1-1-1 



43 



60-11 



9 

 2 



31-2-1-1-1-1-1-1-2-2 





