I 



nvasion of the 

 Multicolored Asian Lady Beetles 



The Multicolored Asian Lady Beetle has been introduced to the United States 

 and has been observed in alarming numbers in other states. 



It has just arrived in New Hampshire. 



JOHN S. WEAVER 



LADY BEETLES, also known as lady- 

 bugs, ladybirds, and ladybird beetles land 

 Coccinellidae if you happen to be an Ento- 

 mologist) owe their common name to the Vir 

 gin Mary, when during the Middle Ages they were 

 called "Beetles of our Lady." Most species of lady- 

 beetles are predators and are regarded as beneficial 

 insects and several species have been used success- 

 fully as biological controls of destructive plant pests 

 such as aphids, mealybugs, and scale insects. 



Several coccinellid species have been introduced 

 by the United States Department of Agriculture to 

 control a number of alien pests, such as the recently 

 introduced Russian Wheat Aphid, which has caused a 

 great deal of crop damage in the West. In the history 

 of introducing new species of lady beetles, there have 

 been many successes and many failures. Often a spe- 

 cies which has shown promise as a predator in the 

 laboratory will not, for one reason or another, survive 

 after being released into the real world. 



The Multicolored Asian Lady Beetle (hereafter 

 MCALB), Harmonia axyridis (Pallas), are native to east- 

 ern Asia and are active predators of several forest 

 pests. Numerous introductions of MCALB were made 

 in the USA from 1916 to 1985. Many releases in the 

 South were made in an attempt to control Pecan 

 Aphids. However, nearly all of these early attempts 

 showed very little measured success. The first no- 

 table recoveries of MCALB in the field were made in 

 1988 in Louisiana, and later, in 1990, in Georgia and 

 Mississippi. Today this species is known from the 

 Carolinas to Maine. 



Along the northern edge of its invasion, MCALB has 

 gained much notoriety for its curious behavior of ag- 

 gregating by the thousands in the fall and seeking 

 sheltered overwintering sites, often in peoples nice 

 warm homes, in the Carolinas and Virginias, large ag- 

 gregations of these beetles around the end of October 

 are not uncommon (hence, another common alias for 

 MCALB is the Halloween Lady Beetle). 



The adult MCALB, like most other coccinellids, is 

 oval and convex. It is 3/16- to 1/4 -inch long and has 

 several different color variations (see cover illustra- 



tions). Adults collected in New Hamp- 

 shire have wing coverings that are orange 

 to orangish-red with as many as 19 black 

 spots, or as few as none. The pronotum is 

 ivory with 4 or 5 black central spots which some- 

 time coalesce into a dark M-shaped band. 



The first specimens of MCALB were taken this sum- 

 mer in New Hampshire from Rockingham to Coos 

 counties by UNH Extension Specialist Alan Eaton in 

 the course of his integrated pest management work in 

 corn and apples. I have also observed a few MCALB 

 adults in my garden this summer, and over the past 

 few weeks, have seen them regularly on some milk- 

 weed plants, heavily invested with aphids, which I al- 

 low to grow among the perennials. These observa- 

 tions suggest that we might be about to witness large 

 aggregations of MCALBs in New Hampshire similar to 

 those which occurred in Pennsylvania and Ohio last 

 year. The importance of mentioning this now is to in- 

 form people of what they might expect to see, so that 

 they won't be alarmed when a few thousand beetles 

 drop by for a visit this October. 



In the fall, the lady beetles will mass together and 

 take flight, apparently searching for a warm sheltered 

 place to overwinter, and at this time may resemble a 

 swarm of bees. Several curious observations of 

 "swarming" ladybugs have been reported from other 

 states. In a typical observation, a homeowner might 

 see large numbers of ladybugs arriving suddenly and 

 landing on the house, garage, barn, trees, etc. The 

 beetles might hang around for several days or fly 

 away in a few hours. Often they gather on the warm 

 southwest or sunny side of a building in the after- 

 noon. MCALBs are attracted to lights and prefer light- 

 colored objects and may congregate near windows and 

 porches or any lighted areas. They will crawl into 

 homes, root cellars, wells, etc., if they can find entry 

 through cracks, vents, or openings into storm windows 



These lady beetles are beneficial and harmless. 

 Hence, insecticides are not recommended as a means 

 of controlling them. To remove ladybugs from the 

 home a mini- or regular vacuum cleaner can be used 

 to collect the live beetles, which can then be released 



OCTOBER / NOVEMBER 



