22 



Nymphs. — As only three of the five nymph stages were observed 

 and described by tlie writer, it has seemed advisable not to publish at 

 this time a technical description of any stages exce^)t the egg and 

 adults. A brief description follows, which will suffice to give a gen- 

 eral idea of the appearance of the innnature stages. 



The newly hatched nymph appears to the naked eye entirely black, 

 but under a lens the abdomen is seen to be very dark slate-colored, 

 with light spots on the lateral margins and a pair of shining l)lack 

 tubercles at the middle of the second and third abdominal segments 

 above. This stage is about 1 mm. in length and nearly as broad as 

 long; the head is api^ressed, making the broadly oval outline almost 

 unbroken; the dorsum is rounded, giving the insect the appearance 

 of a minute turtle. The next two stages are much alike, with reddish 

 or orange border on thorax and abdomen, thorax otherwise blacl(', 

 head black, abdomen sometimes entirely black, but more often dark 

 violaceous with black punctures. The fourth and fifth stages — al- 

 though as stated above not seen by the writer — are without much 

 doubt characterized by a general black, violaceous, or olivaceous 

 black color with a reddish or orange border to the thorax and 

 abdomen as in the first three instars. Also reasoning from what 

 takes place in other pentatomids, without exception as far as known 

 the wing pads first make their appearance in the fourth stage as 

 backward-curving extensions of the sides of the mesonotum, not 

 reaching the posterior margin of the metanotum. In the fifth or 

 last nymph instar of all pentatomids observed by the writer, includ- 

 ing representatives of three genera, the wing pads extend to the 

 middle or slightly beyond the middle of the third abdominal segment. 



Adult. — The original description of the adult of P. ligata by Say 

 is as follows: 



p. ligata. Dull olive green, external edge sanguineous. 



InLabits Missouri. 



Body olive green, rather dull; confluently punctured; antenna? black; second 

 joint rather longer than the third ; thorax, lateral margin sanguineous passing 

 to yellowish on its inner side; scutel at tip bright sanguineous; henielytra san- 

 guineous on the lateral margin nearly to middle, abdomen on the lateral margin 

 from the middle to the tip sanguineous; beneath tinged with yellow on the 

 pectus ; feet greenish, yellowish at base. 



Length, eleven-twentieths of an inch. 



Presented to me by Nuttall as a native of Missouri. The edge of the head is 

 not reddish. 



The top of the head is more closely set with punctures than the 

 thorax and is quite l)lack in all the specimens I have seen; when there 

 is an olivaceous or i)ale tinge it is scarcely noticeable. The basal 

 joint of the antenn;e is sometimes, but not always, pale. The eyes 

 may be entirely black, or, as sometimes occurs, the outer rows of 

 facets are olivaceous or n)ore rarely sliglitly reddish. Tlie under 



