8080 Insects. 



pectoralibus nigris, antennis supra, tibiarura apice tarsisque 

 posterioribus fuscis 9; partium omniuiu colore obscuriori $ . 



Some years the currant bushes {Ribes riihrum) are attacked by little 

 caterpillars, which, from their feeding together in large numbers and 

 being very voracious, soon eat bare whole rows of bushes. I imagine 

 that in years favourable to their development there are three broods ; 

 the first imagos appear in the beginning of May, and the larvae pro- 

 duced from the eggs of these have already undergone their metamor- 

 phosis in the beginning of June (see, on this head, the observations of 

 Bouche), so that by the middle of that month a second brood of 

 imagos has appeared. Now, in June, 1840, I found hundreds of 

 larvae, of which some that I reai-ed produced perfect insects in August ; 

 and in the month of September of the year following I found all the 

 currant bushes at Zwararaerdam eaten bare, and many larvae yet on 

 the branches, so that this may have been the third generation. How- 

 ever, I think we must assume that there are generally but two broods 

 in the year, — namely, imagos in May producing larvae in May and 

 June, these again producing imagos in July, the oflfspring of which 

 pass the month of August in the larval state, and spin up by 

 September, to pass the winter in the cocoon. 



The larva (fig. 1), which is about 16 mm. long, is of a grayish green 

 colour, with paler sides, the first and penultimate and sometimes the 

 terminal segments being yellowish or orange. The head is shining 

 black, with brownish yellow mouth. The whole body is covered 

 with black points, which project more or less, and each bears a single 

 little black hair. These points are arranged in curved rows, the first 

 segment having one, the second two, and the following segments 

 three rows. Besides these at the sides above each leg are one larger 

 and two smaller black shining spots, each spot having little hairs 

 growing on it. The spiracles are white. The larva has twenty legs, 

 so that only the fourth and eleventh segments are apodal ; the six 

 thoracic legs are black and green ringed, with brown claws, the 

 abdominal legs pale green, the anal claspers yellow ; above these last 

 on each side is a little black spine ; I could not discover any trace of 

 the so-called abdominal glands or other secretory apparatus. 



These larvae feed both day and night, and, beginning in company 

 on a leaf, they eat on until there is nothing left but the stalk and 

 some of the thickest veins. Before quitting the bush they moult 

 once more, assuming a pale yellowish green colour, the first and 

 terminal segments being orange, but they are now without the black 



