Page 16 - Volume 4, Issue 2, July 2011

1

Laboratory of Biological Control of Pesticides, De-

partment of Pesticides Control and Phytopharmacy,

Benaki Phytopathological Institute, 8 St. Delta Str.,

GR-145 61 Kifissia (Athens), Greece

2

Technological Educational Institute of Kalamata,

School of Agricultural Technology, Department of

Crop Production, Antikalamos, GR-241 00 Kalamata,

Greece

3

NAGREF, Forest Research Institute, Laboratory of For-

est Entomology, GR-570 06 Vasilika (Thessaloniki),

Greece

Corresponding author:

dimitrios.avtzis@fri.gr

Hellenic Plant Protection Journal

4:

45-52, 2011

First record and molecular identification of the parasitoid

Anagyrus

sp. near

pseudococci

Girault (Hymenoptera:

Encyrtidae) in Greece - Host size preference for the

vine mealybug

Planococcus ficus

(Signoret) (Hemiptera:

Pseudococcidae)

F. Karamaouna

1

, G. Menounou

1,2

, G.J. Stathas

2

and D.N. Avtzis

3

Summary

The parasitoid

Anagyrus

sp. near

pseudococci

(Hymenoptera: Encyrtidae) was recorded for

the first time in Greece and was identified using a PCR-based technique. Once identified, the host size

preference of the parasitoid for the vine mealybug

Planococcus ficus

(Signoret) (Hemiptera: Pseudococci-

dae) was examined in choice experiments with four host size classes (0.5-0.9, 1-1.5, 1.6-2.3 and >2.3 mm)

mostly consisting of one host stage (2

nd

, 3

rd

instar nymph, young female adult and preovipositing female

adult, respectively).

Anagyrus

sp. near

pseudococci

preferably parasitized adult female mealybugs larg-

er than 1.6 mm, whereas no successful parasitism was observed in smaller mealybugs (0.5-1.5 mm).

The mean development time of the parasitoid at the two host size classes where parasitism occurred

was 15.99 ± 0.43 days for females and 17.01 ± 0.53 days for males (28 ± 1

o

C, 16L:8D) and did not statisti-

cally differ between the sexes. Host size at parasitism did not affect the size of female and male para-

sitoid offspring.

Additional keywords

: development, host selection, parasitism, vine mealybug

Introduction

The vine mealybug

P. ficus

is a pest of grape-

vine in the Medditerranean region, North

and South Africa, Middle East, Mexico, Cali-

fornia and Argentina. It is the most common

mealybug species infesting grapevine in

Greece (Heraklio); it has been a key pest on

grapevine in South Africa for more than sev-

enty years and it is a pest of economic im-

portance damaging table and wine grapes

as well as raisins in California (6, 10, 28, 30,

31, 33). Furthermore,

P. ficus

is a vector of the

Grapevine Leafroll Associated Virus 3 (GLRa

V-3) (13) so it is considered economically im-

portant even at low densities (15).

Chemical control of

P. ficus

is difficult

and ineffective as the mealybug feeds on

all parts of the grapevine (roots, trunk, cor-

dons, canes, leaves, fruit) and a portion of its

population often resides in protected loca-

tions i.e. under the bark of the trunk or cor-

don (8, 11, 15, 34). Biological control through

introducing and/or fostering populations of

natural enemies has provided an alternative

method to suppress vine mealybug popu-

lations (7, 12, 34). The parasitoid

Αnagyrus

pseudococci

(Girault) (Hymentopeta: En-

cyrtidae) is the most commonly reared spe-

cies among the natural enemies of the vine

mealybug

P. ficus

(23) as usual with many

Planococcus

spp. and

Pseudococcus

spp. (31).

Similarity in favourable climatic conditions

and geographic distribution between

A.

pseudococci

and the vine melybug renders it

one of the most important biological agents