occurrence of virus and the distribution ing a compatible, practical, and economical pounds in 1976, a tenfold decrease. Much within the state. The surveillance serves research effort. An indirect result of the of the reduction is attributed to more ju- as an early warning system for possible research has been a gradual evolvement dicious and efficient use of chemicals and outbreaks of the disease and provides an of new control strategies being adopted a shift to more effective oil-type formu- overall statewide evaluation of the effec- by mosquito control agencies throughout lations facilitated by University research. tiveness of vector control programs. the state. Reliance on chemical control Instead of oils being applied at dos- has faded appreciably in recent years, age rates of twenty to fifty gallons per Conclusions and the trend has shifted toward inte- acre of mosquito breeding area, as in the past, control is equally effective at rates Voluntary cooperation and collabor- grated management. averaging two gallons per acre. As a re- ation between California mosquito The shift is directly reflected in the sult, labor and material costs have been control agencies and U.C. scientists on records of insecticide consumption of research projects are increasing. The mosquito control agencies. For example, cut deeply and environmental pollution is negligible. close working relationship between the in 1962-the peak year of pesticide ap- ____ --______University of California and the control plication-6615,000 pounds of insecticide Russell E Fontaane z~ Extensaon Entomologzst, Unz versaty of Calafornza, Davzs, and Charles H Schaefer agencies has stimulated and strengthen- were used by California control agencies zs Entomologzst an the Experzmenl Stataon at the Fresno Mosquito Contiol Research Facalaty ed the research program toward achiev- compared with approximately 63,000 -~ --

Exotic dung in pasture~ and __

range land ecosystems- - -~ ~ - John R. Anderson Edmond C.Loomis

ecause they rapidly bury now gradually dispersing and burying economically important pests in California, B dungpadsandthereby reduce pest more dung pads as they expand their comparable in importance to lice, ticks, breeding sites, selected of ex- range. Because cattle (and bison) are not or . otic dung beetles are being imported and native to California, only a few of the na- used as an integrated pest managment tive dung beetles have adapted to cattle Effect on forage tool on California's pasture and range dung. The small native beetles, unfor- Studies at a U.C. field station near land. These beetles are being mass-pro- tunately, have little impact on the vast Marysville have shown that because of duced and released in an attempt to quantities of cattle dung deposited each the smothering of new growth and cattle's simultaneously manage three pests: the year, rejection of the rank growth surrounding horn fly and the face fly, which breed The adverse economic impact of pads, the non-degraded dung pads from only in cattle dung, and the dried-out parasitic worms and horn and face flies one cow cause first-year grazing losses of slabs of dung, which become pests that on the cattle industry is well known, but nearly 0.30 acre, or about $4.50 per cow. smother the growth of new vegetation it is not widely recognized that dried-out At the rate of twelve, 10-inch dung pads for two to four growing seasons. Their dung pads also are a major problem. Re- per cow per day, a 5,000-acre ranch sup- digging also may improve pastures by ac- cent research, however, has revealed porting 450 cattle loses about $2,000 in celerating nutrient recycling and by im- that non-degraded cattle droppings are potential conversion of forage to weight proving soil stability and permeability. Researchers in other areas also have found that dung beetles reduce the num- MANURE CRUST bers of parasitic gastro-intestinal worms that infect cattle. Beef cattle have been the leading monetary commodity in California agri- culture for many years, with dairy cattle 0 0 ranking second. This project could thus 0 BEETLE0 affect much of the 36 million acres of a range land unsuited for other kinds of ag- 0 0 D

riculture, as well as the 700,000 acres of > 0 0 0 irrigated pasture supporting both beef 0 00 and dairy cattle. As noted recently by 0 00 Cl Extension economists, about 65 percent a0 0 of the nearly three million beef cattle 0 a 0 0 produced annually in California obtain all 0 0 their feed from range land. 0 0 0 Exotic dung beetles are expected to represent a permanent, self-perpetuat- ing type of pest management. They are

CALIFORNIA , FEBRUARY 1978 31 gains the first year. Dried-out dung pads of a greenhouse, the California Dung in 100 percent of the dung pads, it is too may smother newly sprouting annual Project has expanded to a point early to evaluate the reproductive suc- vegetation for as long as four years, and where four species of exotic beetles are cess and dispersal of beetles free-released the accumulated losses after three and being mass-reared at U.C. Davis. In 1975, in other areas. However, experience with four years can range from $2,500 to 7,000 beetles of two species were released. similar projects in Australia $3,000. Hence, if exotic dung beetles In 1976, 38,347 beetles were released, and Texas indicates that beetle popula- bury only 25 to 50 percent of existing and during 1977 nearly 250,000 beetles tions did not “explode” and disperse wide- dung pads, they might have a marked ef- were released in California pasture and ly until several years after mass release. fect on forage production as well as par- range lands. All dung beetle species being reared tially reducing parasitic worms and the The exotic beetles have a complex and released in California were received numbers of horn and face flies. The latter life cycle with four stages: egg, larva from quarantine facilities of the pests are reduced or prevented from de- (grub),pupa, and adult. The nesting adults Commonwealth Scientific and Industrial veloping in dung pads rapidly dispersed work in male-female pairs which dig bur- Organization of Australia, and from the and buried by beetles. rows beneath fresh dung pads. Males U.S.D.A. dung beetle project in Texas. The blood-sucking horn fly is as- drop pieces of dung down the burrows All species being released are sociated with reduced milk production where females form the dung into brood beetles of the dung-burying type. and weight gains. The face fly is associat- balls and deposit an egg in each ball. The The release of effective dung-bury- ed with pinkeye and blindness in cattle brood balls are stored in underground ing beetles should establish more produc- and other large mammals, as well as be- tunnels 2 to 18 inches below the soil sur- tive, balanced pasture ecosystems. But ing a general pest of horses, sheep, and face, with the depth depending upon soil since we have found that systemic insec- humans. Horn-fly-associated weight loss- composition and compaction. The eggs ticides provided in cattle rations render es in untreated beef and dairy calves in hatch into larvae which eat the dung cattle dung toxic to both native and exo- California would be equivalent to at least brood balls and rapidly grow. tic dung beetles, as well as to the fly $5 million in a three-month fly season, Field releases have shown that pests, such pesticides should not be ap- while pinkeye treatments and resulting three species - alexis, Onthopha- plied in areas where dung beetles are to blindness cost producers an estimated gus taurus, and gazellu- be established. $1.5 million per year. Current insecticide have successfully overwintered in differ- costs for both horn and face fly control ent parts of the state. Although overwin- John R. Anderson is Professor of Entomology at the University of California, Berkeley; and Edmond C. are estimated at $1.5 million per year. tered Onth. gazellu inhabited 40 percent Loomzs as Extension Parasitologist at the Univer- From its beginning in 1973, when a of new dung pads in a southern California sity of California, Davis. few beetles first were reared in a corner release site and subsequently were found

URBAN PEST MANAGEMENT

The Urban Integrated Control Project under of Biological Control of the University of Tulip trees for Tulip aphids-invaders from the direction of Dr. William Olkowski is cur- California at Berkeley, this spring the pro- the East Coast. Young Klee Orthel watches rently funded jointly by the cities of Palo ject will move to new, larger quarters under the process. Alto, Berkeley, San Jose, Davis, and Modesto, the auspices of the John Muir Institute, a the Palo Alto Unified School District, the , private, non-profit research institution with In the photo at right, crew members of the John Muir Institute, and the Environmental headquarters in Napa, California. Urban Integrated Control project work to- Protection Agency. To date an overall pesti- gether with Public Works personnel in San cide use reduction of over 90 percent has been Monitoring pest and natural enemy Jose. Carefully timed water washing of the achieved by the project in each of the street 1 populations on the street trees in Berkeley trees is a useful strategy for reducing honey- tree systems it has studied. After seven years (left), Linda Orthel (holding bag) and John dew accumulations and enhancing beneficial of being housed in a trailer at the Division 1 Cordwell (on ladder) check the of the effects of the pest’s natural enemies.

32 CALIFORNIA AGRICULTURE, FEBRVARY 1978