February, '16] WHITMARSH: APATETICUS LIFE-HISTORIES 51 



But after all there is no set of rules for migration tests with aphids. 

 It is perhaps only a matter of time and patience. The present national 

 policy of watchful waiting applies as appropriately to the small affairs 

 of the aphid as to larger matters. 



President Glenn W. Herrick: We will now listen to a paper by 

 IMr. R. D. Whitmarsh. 



LIFE-HISTORY NOTES ON APATETICUS CYNICUS AND 

 MACULIVENTRIS 



Bj- R. D. Whitmarsh 



Apateticus cynicus Say 

 This is one of our largest and most common predaceous, brown stink 

 bugs. Unlike its near relative A'pateticus macuUventris, it is but single- 

 brooded. These bugs deposit but a single egg mass, according to my 

 records, which consists, as a rule, of about forty-five eggs. The eggs 

 are laid in late fall and the young emerge from these eggs anywhere from 

 the middle of April to the middle of May, depending on the season. 

 The eggs are of a reddish-brown color, barrel-shaped, and measure 

 about one-tenth of an inch in height by one-sixteenth of an inch across. 

 Like other pentatomid eggs, they are provided with a lid-like cap 

 around which are about twenty short, club-like processes. At the 

 time of hatching this lid lifts and a light reddish colored insect emerges 

 which soon becomes dark red with black head and thorax and black 

 spots along the dorsal portion of the abdomen. The length of time 

 spent in the different instars depends greatly on the amount of food 

 which the bugs are able to find. Under favorable conditions they will 

 pass through the various immature stages and become adult in a 

 little over a month and a half. LTnder unfavorable conditions they 

 may not reach maturity in less than two and a half months. Follow- 

 ing is the approximate time which elapses when the insects occur 

 under favorable conditions : From the time of the hatching of the egg 

 to the first molt, 5 days; second instar, 5 days; third instar, 1 week; 

 fourth instar, 2 weeks; fifth instar, 3 Aveeks. Under our conditions 

 of climate the majority of the insects become adult between'the middle 

 of June and the middle of July. Ordinarily, mating takes place from 

 two to three weeks after the insects become adult, and continues 

 at intervals throughout the remainder of the summer. The males 

 usually commence djing off about the first of September, while the 



