The First Finding of The Fig Psylla Homotoma ficus L . ( Hemiptera , Psylloidea , Homotomidae ) in Serbia

The fig psylla Homotoma ficus (Homotomidae, Psylloidea) is reported for the first time from Serbia where it has recently been found in 12 localities. It is a Mediterranean species which has been introduced together with cultivated fig plants also outside their original distributional range. It can cause economic damage on its host in certain years. A diagnosis and illustrations of adult, larva and egg of H. ficus are provided and information is given on its distribution, life cycle and natural enemies in Serbia.


INTRODUCTION
Jumping plant lice (Hemiptera: Psylloidea) is a relatively small group of phytophagous sap-sucking insects with usually narrow host ranges.It is currently classified into six families (Burckhardt, 2005).One of the smaller families is the Homotomidae which includes about 80 species worldwide, all of them associated with the plant family Moraceae and mainly the genus Ficus (Hollis and Broomfield, 1989;Hollis 2004).A single species, Homotoma ficus (Linnaeus, 1758) feeding on fig (Ficus carica) is present in warm regions of western Palaearctic (Burckhardt, 2011;Klimaszewski, 1973).
According to earlier investigations in regions of fig cultivation on larger parcels, H. ficus appears periodically in larger number when larval feeding can lead to some damage on fig leaves, but mostly the species is not considered as an economically significant pest (Burckhardt, 1994).Economic damage has however recently been reported by Gencer et al. (2007).It is due to direct effects of larval and adult feeding on leaves, and sometimes on fruits as well, and development of sooty mold as a consequence of honeydew excretion by larvae and adults.The sooty mold inhibits respiration and photosynthesis of infested plants and also reduces the market value of infested fig fruits.
The fig psylla H. ficus was registered for the first time in Serbia in Belgrade (Voždovac) in 2007, after that it was found also in other localities in the country.This paper reviews the diagnostic morphological features of adults, larvae and eggs, and the information on the biology and distribution of H. ficus in Serbia.

MATERIAL AND METHODS
The material was being collected from 2007 to 2009 in altogether 21 localities in Serbia (Figure 1) (ten of them were from Belgrade), using visual inspection of Ficus carica L. The adults were collected from the host plants with an aspirator, the larvae of different instars and eggs were collected together with the plant organs on which they were found.The material was fixed in 70% ethanol for further analysis.In order to make the tracking of first instars hatching easier, branches on which eggs were laid, were collected during February and March and put into Petri dishes in laboratory conditions at room temperature.Fifth-instar larvae were reared in Petri dishes until they became adults.The reared adults and fifth-instar larvae were fixed in 70% ethanol and used for slide making.For microscopic observation and drawings, eggs were cleared in lactic acid, and then transferred in Kieffer medium using a modified method according to Kieffer (Amrine and Manson, 1996).Fifth-instar larvae and adults were macerated in 10% KOH and permanently mounted in Canada balsam (Hodkinson and White 1979).Biology of H. ficus was investigated in field conditions.

Biology
The fig psylla has one generation per year.It overwinters in the egg stage on the host plant.In laboratory conditions, larvae of H. ficus started hatching on March 17, 2008.In field conditions, hatching was registered on March 26.Larvae of the first and second instar are hidden under flaked bud leaves.From the third instar on, larvae are concentrated on both sides of leaf veins on the lower side of the leaf (Figure 7).The presence of thirdinstar larvae was registered on April 25.The number of larvae per leaf was between 2 and 20.While feeding, larvae excrete honeydew which is usually wrapped in wax, so their presence can be recognized by wax secretion in the form of drops or threads on leaves.The first eclosion of adults was registered at the end of May (May 26, 2007 andMay 30, 2008).During summer (June to August), adults were found on fig mostly on lower sides of the leaves, concentrated near major leaf veins.Copulation was observed at the end of August and during September, first laid eggs were registered in September (September 17, 2007 andSeptember 1, 2008).Eggs were laid near leaf buds and in the folds of the bark in small groups.

Natural enemies
During investigations of the biology of the fig psylla, the presence of two species of predatory bugs was registered.Malacocoris chlorizans Panzer (Heteroptera: Miridae) was found in all localities where the fig psylla was present and was observed to feed on larvae of H. ficus.Furthemore, Orius minutus (L.) (Heteroptera: Anthocoridae) was registered as an egg predator of H. ficus.

DISCUSSION
According to literature, fig psylla Homotoma ficus has one generation per year and overwinters in the egg stage on host plant (Boselli, 1929;Dobreanu and Manolache, 1962;Loginova, 1968;Burckhardt, 1994;Gencer et al., 2007).During our investigations, we confirmed that fig psylla H. ficus has one generation per year and that it overwinters in the egg stage on host plant, which coincides with previously mentioned authors.
For the region of the Crimea, Loginova, 1968, found that larvae start hatching at the beginning of April, and she registered the first eclosion of adults in mid-June, while in coastal part of Georgia she noted that the development of H. ficus was about two weeks later.Dobreanu and Manolache, 1962, cite that in the region of France (Montpellier) larvae hatch during February and March.Gencer et al. (2007) cite that in the region of Turkey larvae hatch at the beginning of April and the eclosion of adults is in May.
Similar data were obtained during these investigations.The beginning of larvae hatching in our conditions is at the end of March or beginning of April.Firstinstars and second-instars are hidden under flaked bud leaves.From the third stage of development larvae concentrate on lower side of a leaf, on both sides of leaf nerves.First ecloded adults are registered at the end of May and beginning of June.
Loginova, 1968, found that in the region of the Crimea, adults stay on fig usually 7-10 days after eclosion, and then move to other plants, such as conifers, oak, horse-chestnut, hawthorn and date.Loginova registered the return to the host plant in September when she also registered first laid eggs.However, Gencer et al., 2007, cites that adults are on fig from May until the end of September in the region of Turkey, and that they lay eggs in October.
In our investigations during summer months, adults of H. ficus could be found on fig, mostly on sunny parts of the crown (south and south-west exposition) and mostly on lower part of the leaf.At the end of August and beginning of September, adults could be found copulating, and first laid eggs were registered at the beginning of September.
H. ficus is originally distributed in the Mediterranean area and the Middle East.However, it has been introduced together with the host plant in other countries outside the original distributional range, too.Hodkinson and White (1979) register it from the Great Britain.Burckhardt and Mühlethaler (2003) report it from Switzerland.According to Mijušković, 1999, andSeljak, 2006, H. ficus is also present in coastal regions of Slovenia, Croatia and Montenegro.Halperin et al., 1982, andGencer et al., 2007, registered

Figure 1 .
Figure 1.Map of inspected localities in UTM projection (original)
fig psylla in the USA (California), too.