EUROPEAN AND MEDITERRANEAN PLANT PROTECTION ORGANIZATION
00/7909
PPM Point 8.5/PPot Point 3.2.2
North American Phyllophaga spp.
Identity
Taxonomic position: Insecta: Coleoptera: Scarabeidae
Notes on taxonomy and nomenclature: There are over 200 Phyllophaga species in North
America. According to the literature, only three have specifically been reported as pests
(excluding P. ephilida, which has already been studied at the last meeting, and which has a
more southern distribution and attacks sweet potato). These are Phyllophaga anxia,
Phyllophaga fusca and P. implicita.
 P. anxia
Name: Phyllophaga anxia Leconte
Synonyms: Lachnosterna anxia
Lachnosterna dubia
Common names: common June beetle (English)
barbeau (French, Canada)
cranberry white grub (English)
 P. fusca
Name: Phyllophaga fusca (Froelich)
Synonyms: Lachnosterna fusca (Froelich)
Common names: northern June beetle (English)
hanneton du nord (French, Canada)
Bayer code: PHYGFS
 P. implicita
Name: Phyllophaga implicita (Horn)
Synonyms: Lachnosterna implicita Horn
Bayer code: PHYGIM
Hosts
Phyllophaga spp. are polyphagous pests. The adults feed on the foliage of forest and shade
trees. They are strongly attracted to fragrant flowers and ripe fruits. The preferred host of P.
implicita adults are Salix spp. and Populus spp. Adults of P. anxia are reported in Québec to
feed on elm, oak, poplar, rose, aspen, ash, raspberry, willow, cherries, Alnus, walnut, birch
etc., and also on flower petals of plants such as apple and lilac.
The larvae (white grubs) feed especially on the roots of fibrous-rooted plants. Stronger taprooted plants are often tolerant to injury. Phyllophaga spp. attack maize, timothy, lespedeza,
Kentucky bluegrass, sorghum, soybean, strawberry, potato, barley, oat, wheat, rye, bean,
turnip, cranberry and other cultivated crops. They also infest various pasture grasses, lawns
and nursery plantings.
P. anxia is reported specifically on Abies fraseri (Fraser fir) and maize. In Canada, it is
reported as causing damage mainly to potato but attacks in young pine, larch and oak
plantings are also mentioned. P. fusca mainly attacks grasses (and also Abies fraseri), and P.
implicita mainly maize and soybean. In south-eastern Dakota, P. implicita is reported as
causing damage to maize, wheat, oats, barley, sugarbeet, soybean, potatoes.
Geographical distribution
EPPO region: Absent
North America:
For Canada, the distribution is taken from Bousquet (1991). It does not correspond to that of
Arnett (1993) which reports Phyllophaga spp. only in the south-east and north-east of North
America, and in Oklahoma. The main Phyllophaga sp. in Canada is P. anxia.
In USA, Phyllophaga spp. are often treated together and are reported as widespread. The web
site of North Carolina State University mention that they are present mainly in north central
states and New England. For USA, the geographical distribution given below has mostly been
established using fragmentary information from scientific abstracts or the Web sites of state
extension services or universities. This gives an indication of the geographical range but it is
certainly incomplete. In Iowa, the main Phyllophaga spp. (in numbers) are reported as being
P. balia and P. futilis, with the three below being less important. Funt et al. (1997) quote
Phyllophaga spp. as pests of strawberry in the Midwest, without details on the species
concerned.
 P. anxia: Canada (Northern Territories, British Columbia, Alberta, Saskatchewan,
Manitoba, Ontario, Québec, New Brunswick, Nova Scotia, Prince Edward Island,
Newfoundland), USA (Nebraska, Massachusetts, North Carolina, North Dakota, Iowa)
 P. fusca: Canada (British Columbia, Ontario, Québec, Nova Scotia, Newfoundland); USA
(North Carolina, Iowa)
 P. implicita: USA (North Dakota, Iowa). Reported as the most abundant Phyllophaga spp. in
southeastern North Dakota.
Biology
Larval infestations are greatly influenced by soil type or texture. Infestations by Phyllophaga
spp. are reported to be more common in light, sandy soils that are well-drained than in poorly
drained, heavy clay soils. Phyllophaga spp. have one generation approximately every 3 years.
Generations overlap so that adults and larvae are present every year.
Females deposit eggs in soil during late spring or early summer (20 to 50 eggs). They
especially prefer grass sod near wooded areas for egg-laying. Eggs hatch in 2 to 4 weeks (up
to 7 weeks reported in North Dakota for P. implicita). Newly-hatched larvae first feed on
organic matter, then on crop roots throughout the summer. Most larvae reach the second instar
stage before soil temperatures begin to decline in the autumn, then burrow deep in the soil to
overwinter (below the frostline, sometimes 1.5 m). The following year they again migrate to
the root zone to feed (around end of May). These larger larvae cause much greater damage
than they did the year before. Larvae moult to the third instar by July and continue feeding
through the entire summer, being found in the upper 15 cm at the base of plants until a killing
frost. After overwintering again well below the soil surface, the larvae feed on seedling roots,
but seldom cause significant losses, because they pupate early in the summer. Adults emerge
from pupal cells in the spring three years after the cycle began. The adults hide in the soil
during the day and fly to trees to feed at night. The year of greatest injury corresponds with the
second year of the life cycle, when second instars are the most numerous in the spring. For P.
fusca and P. anxia, Guppy (1982) reports that first flight of overwintering adults occurred in
mid-May with the accumulation of about 156 day-degree above 5°C beginning on 1st April.
P. anxia naturally carries a virus (phyllophaga anxia iridescent virus, PaIV) which has little
significance in nature (Poprawski & Yule, 1990).
Detection and identification
Symptoms
Larvae eat the roots and may cause death of plants. The main symptoms are yellowing and
wilting of the plants, mainly of grasses. Fraser fir seedlings show yellowing of the needles and
death.
Morphology
Eggs
Pearly white, becoming dark just before hatching. Oval to spherical shaped, the eggs are 1.5 to
3 mm in diameter and encased in a cell of soil particles.
Larva
C-shaped larvae are creamy white to whitish gray with distinct brown heads and three well
formed pairs of legs. Young grubs are 5 mm long and fully grown larvae range from 20 to 45
mm long depending upon the species. Two rows of hairs on the underside of the last segment
distinguish white grubs from similar grubs.
Pupa
Approximately the same size as the adult, the pupae may be creamy white, pale yellow, or
dark brown.
Adult
Adults are called May beetles or June beetles. They range in length from 15 mm to 30 mm.
They vary in colour from reddish-brown to dark brown, and are shiny. They are robust,
oblong, and hard-shelled.
Detection and inspection methods
Phyllophaga spp. can be trapped using light traps, chemical lures using sex pheromones,
examining the host plants for beetles, and soil sampling for grub populations.
Means of movement and dispersal
The beetles are generally weak fliers and can travel on the wind. Larvae may be transported in
soil around the roots of plants for planting, but are rather large to be readily carried in traces of
soil on vegetables.
Pest significance
Economic impact
Some authors consider that white grubs are amongst the most destructive soil insects in North
America. They destroy root systems by feeding and tunnelling. When numerous, the larvae
can cause severe mechanical plant damage by uprooting plants during movement. The
structure of the soil can be modified and plant establishment affected. However, in the
literature, it is difficult to see the relative importance of species. Moreover, the situation of
these pests seems stable. Duval (1993) refers to a brochure published in 1934 by the Ministry
of agriculture of the Quebec province on how to control white grubs.
Adults cause serious damage to trees and shrubs only when they are in large numbers (Duval,
1993). They feed on leaves in late summer and skeletonize them.
Damage by larvae mostly occur in spring or autumn when the soil is very damp. Damage in
grassland, lawns or golf courts is particularly visible. The plants are weakened and may
eventually die. White grubs may kill plantings of pine, larch and oak (Duval, 1993).
Infestations on Fraser fir are highest in new plantings established on newly ploughed sod or
other grasses. They result in or death (Sidebottom & Mc Graw, 1993) Root injury weakens the
fir plants and also provides an entry site for root diseases.
We have not found any specific reference to damage to potato, apart from the statement by
Duval that P. anxia attacks mostly potato in Canada. However, we supposed that damage on
potato is similar to that caused by white grubs in Europe (e.g. Melolontha spp.), i.e. that larvae
gnaw the tubers.
Phyllophaga is reported as a vector of Pantoea stewartii. (EPPO A2 pest) but we have not
found other mentions of this (IPM Alabama home page:
www.aces.edu/department/ipm/anr601.htm).
Control
The method mentioned as the most reliable is a suitable crop rotation. Susceptible crops
should be avoided (i.e. maize, strawberry or potato) after grassland. Rotation should be with
non-susceptible or resistant crops such as oat, rye, clover, orchard grass or lucerne.
Other cultural methods include ploughing when the larvae are in the corresponding layer of
the soil, and not cutting the grass too short, which deters females from laying eggs. Watering
should be adapted. For example, females will not lay eggs if the soil surface is not moist, and
it is advised to water lawns at intervals to allow the surface to dry. In grasses which have
already been damaged, light frequent watering is preferable during warm periods.
Chemical control is routinely used, by soil treatment pre-planting or on established crops.
Lim et al. (1981) list 16 parasitoids and predators of P. anxia in Quebec, some of which have
an important role in the control of populations. The Dipteran Microphthalma michiganensis
parasites 45% of 2nd and 3rd instar larvae according to Petch et Hammond (1926). The use of
entomopathogenic nematodes has also been investigated (Heterorhabditis heliothids,
Steinernema carpocapsae and S. glaseri). Bacillus bacteria have been used, but they do not
establish in northern soils.
Phytosanitary risk
Phyllophaga spp. could certainly cause damage to crops in the EPPO region but would find
themselves in competition with widespread and damaging Palaearctic chafer beetle larvae
(e.g. Melolontha spp.). It is not sure how Phyllophaga spp. could reach Europe since there are
no obvious pathways. They have never spread outside of North America and have not
attracted much attention in text books on pests. In particular, they are not regarded as invasive
pests, but rather as a stable element of the entomofauna. They are not quarantine pests for any
other RPPO but European Melolontha have been regarded as quarantine pests by other
continents. The species that seems the most important for potato, Phyllophaga anxia, is
present in a wide range of climatic and environmental conditions, but would not find suitable
environmental conditions in the south of the EPPO region.
Phytosanitary measures
These pests could be covered by general measures against soil pests, i.e. freedom from soil or
application of EPPO Phytosanitary procedure no. 54 on growing plants prior to export (for
nursery forest trees?).
Bibliography
Anon. (?) White grubs. ipmwww.ncsu.edu/AG271/forages/white_grub.html
CABI Crop Protection Compendium
Arnett R.H. (1993) American insects. A handbook of the insects of America North of Mexico. The Sandhill Crane Press, Inc.
Florida
Bousquet Y. (1991) Checklist of beetles of Canada and Alaska. Agriculture Canada
Di Pirro M., Glogoza, P.A. Weiss, M White grub management. North Dakota State University Entomology department
http://www.ext.nodak.edu/extpubs/plantsci/pests/whitgrub/whitgrub.htm
Duval, J. (1993) Le hanneton commun et les vers blancs. http://eap.mcgill.ca/agrobio/ab360-06.htm
Guppy, J.C. (1982) Effects of temperature and light intensity on nocturnal activity patterns of the northern June beetle,
Phyllophaga fusca, and the common June beetle, P. anxia (Coleoptera: Scarabeidae). Canadian entomologist, 114, 11511157
Kard, B., Hain, F. (1987) Chemical control of three white grub species (Coleoptera: Scarabeidae) attacking Fraser Christmas
trees in the Appalachians. Journal of entomological science. 22, 84-89
Lim, K.P., Stewart R.K. Yule, W.N. (1980) A historical review of the bionomics and control of Phyllophaga anxia (LeConte)
(Coleoptera: Scarabeidae), with special reference to Quebec Annals of the entomological society of Quebec, 25, 163-178.
Lim, K.P., Stewart R.K. Yule, W.N. (1981) Natural enemies of the common June beetle, Phyllophaga anxia (Coleoptera:
Scarabeidae), in southern Quebec. Annales de la Société Entomologique du Québec, 26, 14-27
Funt R.C., Ellis M. A., Welty C (1997?) Small fruit pest management handbook Bulletin 861. Chapter 1 strawberries, Ohio
state university Midwest http://www2.ag.ohio-state.edu/~ohioline/b861/b861_16.htm
Poprawski T.J. (1994) Insect parasites and predators of Phyllophaga anxia (LeConte) (Col., Scarabeidae) in Quebec, Canada.
Rice M. E. (1998) rarity in ubiquous insects - the June beetles. http://www.ent.iastate.edu/entsoc/ncb98/prog/abs/125.html
Rivers R.L., Pike, K.S., Mayo, Z.B. (1977) Influence of insecticides and corn tillage systems on larvae control of
Phyllophaga anxia. Journal of economic entomology, 70, 794-796.
Sidebottom J. McGraw (1993) North Carolina Coopretaive Extension Service White grub control in Fraser fir Christmas
trees