THE GREEN JUNE BEETLE OR FIG EATER J. J. DAVIS AND PHILIP LUGINBILL, NORTH CAROLINA AGRICULTURAL EXPERIMENT STATION CONDUCTED JOINTLY BY THE STATE DEPARTMENT RALEIGH By JOHN J. DAVIS and PHILIP LUGINBILL Entomological Assistants, Cereal and Forage Insect Investigations INTRODUCTION The green June beetle (Cotinis nitida L.),2 or fig eater, as it is sometimes termed, is one of the most common and conspicuous insects of the South, and numerous inquiries relative to it or to the immature form, the grub, are received annually. It is hardly likely that the grub is directly responsible for killing grass, as is quite generally supposed, and this feature will be fully discussed in a following paragraph. Indirectly the grubs have been responsible for considerable injury to field crops, such as alfalfa as well as to golf greens-injuries which made necessary the investigations herewith reported. The adults, the velvety green June beetles, frequently attack fruit, especially figs, grapes, and peaches, and occasionally injury to other crops, such as corn, is reported. Our studies on the common white grubs (Lachnosterna spp.), have naturally led to a study of related genera, particular reference being made to the habits and work of the larvæ and means of distinguishing one from the other. Although our common white grubs are by far the most important from the economic viewpoint, it is nevertheless of greatest. importance that farmers and others, as well as entomologists, be able to recognize readily the related species in the larval or grub stage, whether they be directly or indirectly injurious or simply scavengers. This publication not only treats of the economic status of the grub of the green June beetle, but gives also simple characters for the identification of the related species likely to be confused. Our investigations on the life history and habits of this insect were made at Columbia, S. C., by the junior author, and at Louisville, Ky., and Lafayette, Ind., by the senior author.3 INJURY The adult beetles are frequently reported injuring fruits of various kinds, including figs, peaches, grapes, plums, apricots, prunes, nectarines, pears, apples, raspberries, and blackberries. Of these, the thinskinned fruits, especially figs, peaches and grapes, are most often damaged, the other fruits listed above being only occasionally or slightly attacked. Injury to figs in South Carolina, Georgia, and other Southern This bulletin is of interest to farmers, gardeners, and others in North Carolina and other Southern States. Published with the approval of Dr. L. O. Howard, Chief, Bureau of Entomology. Washington, D. C. "More commonly known under the name Allorhina nitida. This opportunity is taken to acknowledge the assistance of Mr. A. F. Satterthwait of this office in the care of breeding cages during the spring of 1913. States is an annual occurrence, and indeed one of the popular names of this beetle, fig eater, originated from its prevalent habit of feeding on this fruit. From Pennsylvania southward comes the frequent report of injury to peaches, very often to those which are quite sound, contrary to the opinion of some authors that only decaying, partially decayed, or overripe fruit is attacked. The green June beetle is likewise a wellknown grape pest, and Prof. H. Garman reports injuries to this fruit in Kentucky as follows: "The common green June bug, well known to every Kentucky schoolboy, becomes very troublesome locally, and occasionally by cutting the skins of grapes and utterly destroying the fruit of whole bunches and even whole vines. On the experiment farm at Lexington this pest would, if allowed to work unhindered, destroy the whole crop of the early varieties in the experimental vineyard. It was formerly more troublesome than now, but is liable any season to appear in such numbers as to be the cause of anxiety on the part of those having the vineyard in charge. The very sweet, thin-skinned, early sorts suffer most severely. On a visit to the vineyard August 1, 1896, I found Moore's Early, Poughkeepsie, and White Imperial being severely damaged, while Brilliant was only moderately injured. The clumsy beetles were clinging to the berries, in some cases a dozen on a bunch, greedily devouring the pulp and leaving them in an unsightly and utterly ruined condition. They were guilty of injury to early peaches and plums during the same month." (Garman, 1904.) Besides the orchard fruits, Webster and Mally report injury to tomatoes by these beetles in southern Ohio (Webster and Mally, 1897), and even such fruits as melons are sometimes eaten. Corn in the ear is a favorite food of the beetles, which not infrequently are sufficiently numerous to injure noticeably both field and sweet corn. They have even been observed injuring young corn plants by gnawing into the stalk, and in one instance young sorghum plants were attacked. Their fondness for sweets sometimes tempts the beetles to enter beehives, thereby causing more or less disturbance. Three unusual feeding habits have been previously reported. Mr. Charles W. Long observed the beetles attacking walnut trees and described the injury as follows: "They appeared to bite through the bark, making a hole one-eighth inch wide and one-half to three-fourths inch long. The bark seemed to be softened with some exudation from the mouth." (Leng, 1884.) In 1888 Mr. W. W. Meech, of Vineland, N. J., found beetles feeding greedily on the fungus Roestilia aurantiaea on quince trees (Riley and Howard, 1888), and in 1891 Mr. Frank Triplett observed them boring into and extracting sap from tender branches of black oaks at Springfield, Mo., the injury causing the leaves to wither and the branches to dry and break off. In the latter case the attack seemed to be confined to the tops of the trees. (Riley and Howard, 1891.) The beetles are sometimes a nuisance in well-kept lawns and golf ens, due to the little mounds of earth excavated by them as they er the ground. The grubs have been considered serious enemies of lawns and garden ps for years, although the most recent authorities have rejected this V. From the facts that we have gathered, the grubs may damage ps under unusual conditions, but most of the injury reported is either irect or grubs of the genus Lachnosterna, our common and most deactive white grubs, were associated, and doubtless they and not the inis grubs were responsible for the direct injury; or, noticing the bs in conspicuous numbers, injury may only have been anticipated the observer. It is unquestionable that these grubs prefer soil heavily tilized with animal manures; and, further, that they may and usually live and mature in manure or similar decomposing matter. Prof. H. rman concludes that "it is now known that they (grubs of Cotinis da) feed only on dead vegetable matter, manure, compost and the like, 1 are consequently most numerous where food of this sort is most undant, viz., about heavily enriched land, and in the vicinity of old ups of decaying manure." (Garman, 1904.) We are able to corroboe Garman's statement that these grubs may live and complete their nsformation in soil completely devoid of any living vegetation. Dr. ward (1879) called attention to the fresh and green condition of the vns at the Capitol grounds in Washington in spite of the fact that abs occurred in enormous numbers in the ground. The same author 98), in the most complete article on this species published prior to = present one, says: "The actual amount of damage done by these væ is problematical, and in fact it is even problematical whether they rmally do damage at all." And again, "Taking all these considerans together, it is probably safe to say that the normal food of the lorhina larva is the vegetable mold of rich soils, and that in its larval ge it is not a crop pest." And again, "In view of the well-known bits of the Cetonians, all of the species of which, whose bits are known, being feeders upon decaying vegetation only, it seems ange that the root-feeding hypothesis should ever have been adopted. obably the basis of such an hypothesis was the great abundance of the væ in the soil and their resemblance to Lachnosterna larvæ." Instances where the grubs of the green June beetle were directly jurious are few. Fruit lying on the ground, or such crops as celery, dive, etc., which are covered for bleaching and afford excellent condions for the grubs, may be directly attacked and damaged, especially the grubs are abundant. On the other hand, reports of injury to crops as grass, strawberries, corn, alfalfa, etc., by the eating of the ots, are probably incorrect; at any rate we have never been able to rify such reports. ch .. Indirectly the grubs may considerably damage garden and field crops. well as lawns and meadows by their tunneling and burrowing, up |