56 



SCALE INSECTS. HemiptefaV 



Cotton in the West Indies has been attacked by two 

 species of scale insects which are commonly known as the 

 black scale and the white scale. The black scale (Saissetia 

 nigra, Nietn.) has been a very serious pest, especially in 



ig 1 . 55. Black scale on cotton. 

 Slightly enlarged. (Original.) 



Barbados, where in 1905, several fields of cotton were a total 

 loss owing to the severity of the attack of this pest. At tl^e 

 present time, black scale attracts very little attention and 

 has ceased to be regarded as a pest by most planters. This 

 changed condition has been brought about by the develop- 

 ment of the parasite of the black scale. This beneficial 

 insect is now known to occur throughout the West Indies. 

 It was first reared from the black scale in Barbados in 

 1907, and specimens were submitted to the United States 

 Department of Agriculture for identification. Through 

 the courtesy of Dr. L. O. Howard, Chief of the Bureau of 

 Entomology, these were studied by Mr. J. C. Crawford 

 who found the insect to be a species new to science to 

 which he gave the name Zalophothrix mirum. The insect 

 is very small (about T Vmch in length), at first glance resem- 

 bling a small ant with rather short wings. Its general 

 colour is dark-brown, the head bearing conspicuous 

 reddish brown eyes ; the transparent wings are crossed 

 by a broad dark band near the middle. The eo-g o f the 

 parasite is deposited by the female under the body of 

 the scale insect, about the time that the latter begins to 

 produce eggs. The parasite grub hatches in the midst of 



