February, '17] COOLEY: SPINACH CARRION beetle 97 



Some are more nearly spherical than others. See Plate 5, figure 2. It has been 

 found also that the eggs increase in size after being laid. This subject is discussed 

 more thoroughly in another paragraph. 



First Instah: — Length, 5 to 6 mm.; width of head, 1.30 to 1.80 mm.; width of 

 body, 2.00 to 2.70 mm. All well chitinized parts, black; connecting membranes, 

 white. Head well rounded, antennae with three nearly equal joints, third joint with 

 a distinct terminal sensorium beneath. Two ocelli beneath base of antennse and 

 group of foiu" above. Mouthparts short and fleshy, maxillary palpi four jointed, 

 labial palpi two jointed. The dorsal wall of the body is made up of a series of strongly 

 chitinized, transverse plates, which project laterally and terminate posteriorly in a 

 sharp corner. The plates of the three thoracic segments are wider than the abdom- 

 inal plates, and, of these three, the anterior one is largest and the second one, inter- 

 mediate in size. Segments, thirteen; segment twelve bearing a pair of two-jointed 

 cerci. On the ventral surface, the abdominal segments, excepting the first, have 

 transverse plates as above. The thoracic and first abdominal segments are mainly 

 membranous. Coxae elongated, tubular and well chitinized. Terminal segment 

 with the dorsal and ventral walls joined, tubular. Head, including antennae, and 

 body, excepting membranous portions and including the legs, sparingly clothed with 

 short bristles or spines of varying length. See Plate 5, figure 3. 



Second Instar: — Length, 6.50 to 9.50 mm.; width of head, 1.70 to 2.00 mm.; 

 width of body, 3.00 to 3.50 mm. Otherwise the second instar is like the first. See 

 Plate 5, figure 4. 



Third Instar: — Length, 11.00 to 15.00 mm.; width of head, 2.20 to 2.75 mm.; 

 width of body, 4.80 to 5.20 mm. Otherwise the third instar is hke the first and 

 second. See Plate 5, figure 5. 



Pupa: — Length 13.50 mm.; width of pronotum, 6.00 mm.; width of abdomen 5.00 

 mm. Entirely white, soft. Antennae, legs and wings, free. On the anterior margin 

 of the pronotum, on each side, are two large spines directed forward. Abdominal 

 segments 2 to 8 inclusive, each with a long, curved bristle on each side. At the tip 

 of the abdomen is a pair of elongations directed backward and on the tip of each is a 

 long bristle. See Plate 5, figure 6. 



First Appearance in the Spring 



The adult beetles may often be found sparingly among the first 

 insects out in the spring. They may be seen crawling on the ground 

 before any vegetation has started. The earliest occurrence of which 

 we have an actual record is March 15. It is quite clear that both 

 adults and some larvse appear long before the sugar beet crop is planted. 



Egg Laying 



The eggs are laid in the soil. A preference is shown for moist soil 

 and the eggs may be found under the surface as deep as two inches. 

 In depositing the eggs the insect may extend the tip of the abdomen 

 into the soil for some depth or burrow under the surface. The female 

 has been seen in the act of laying eggs in the field. The tip of the 

 abdomen was extended down into cracks in the soil for the purpose. 

 It is probable that in nature the eggs are always laid under the surface, 

 though in the insectary, -some were laid on the surface. 



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