Chilocorus kwwanae 



m 



A NEW BIOEOGICAI, 



CONTROL FOR 



EUONYMUS 



SCALE 



Cuonymus plants are versatile and attractive 

 ornamentals that grow throughout much of 

 New Hampshire. They rank as 12* among the most 

 commonly used plants in United States landscaping 

 and they come in many forms, including bushes, 

 climbing vines, groundcovers, and small trees. The 

 common evergreen types retain their leaves, but the 

 popular burning-bush, or winged-euonymus, is de- 

 ciduous. The evergreen varieties of euonymus are 

 susceptible to a minute insect pest known as the 

 Euonymus scale. The mature scale insect itself 

 looks like a minute white speck, but heavy infestations result in whitened bark and 

 discolored leaves. Plants heavily infested will eventually die, unless insecticides 

 (doimant oils and summer sprays) are applied. 



Euonymus scale is a pest of foreign origin, having probably arrived in this country 

 along with the many varieties of euonymus which were imported to the United States 

 from Asia. Unfortunately, most of the scale's natural enemies were left behind, and 

 without its natural biological controls here in North America, the scale has become a 

 serious problem. 



A new effort is being made this year through the Entomology Department of the 

 University of New Hampshire to introduce a natural predator to control Euonymus 

 Scale in New Hampshire. The friendly predator, an Asian lady beetle, Chilocorus 

 kuwanae, has an inordinate fondness for eating euonymus scale and has been shown to be 

 a viable biological control of the scale. Despite recent release efforts involving Chilocorus 

 kuwanae in the Northeast by the United States Department of Agriculture GJSDA), this 

 species of lady beetle has not yet become established in New Hampshire. However, 

 this lady beetle has already been a great triumph in Massachusetts, where much of 

 the success can be attributed to the biological program of Dr. Roy van Driesche, Ento- 

 mology Department, University of Massachusetts. Dr. van Driesche has kindly 

 supplied enough lady beetles to UNH to start a small colony of the lady beetles. It is 

 anticipated that the colony will grow in numbers, so that this summer it will be 

 possible to make several releases of lady beetles on the UNH campus in Durham, 

 where there is presently a severe infestation of the scale. Hopefully this new project, 

 supported in part by USDA, wUl be a success and facilitate the introduction of an 

 effective biological control of Euonymus scale in New Hampshire. 



Anyone in New Hampshire who would like to obtain a small batch of lady beetles 

 to control Euonymus Scale must contact the author and be willing make a trip to Durham 

 this summer to pick up the lady beetles. (Also, you will need to bring along a container, like 

 a large peanut butter jar, and a cool ice chest to transport the lady beetles safely.) ^^ 

 John is Survey Entomologist in the Entomology Department at the University of New 

 Hampshire, Durham, NH 03824. Phone: (603)862-1737. 



ritten and IRustrated by 

 Dr. John Weaver 



April & May 1993 

 23 



