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A holiday item: the Cistus miner Dicladispa testacea

During a short holiday in the Tro÷dos Mountains of Cyprus (end April-early May) numerous mines were found on Cistus salviifolius, apparently belonging to this species. Cyprus can hardly be considered to fall within the region of interest of the UK or Dutch leaf mines fanciers. Yet, the species seems to be common in at least the Eastern Mediterranean, and may be met by several of you at some moment. Therefore I'd like to give a short description of the mine.

Dicladispa testacea (Linnaeus) belongs to the Chrysomelidae  (subfamily Hispinae). The imagines are characterized by numerous long outstanding spines all over the dorsal side of the body. All species of this mainly (sub-) tropical subfamily are leafminers.

 

 

Mines of the species was recorded from the Dalmatian Island of Hvar by Buhr in 1930. Hering (1967) revisited the island and found the species to be quite common there. The hostplants mentioned from Hvar are Cistus monspeliensis, salviifolius and villosus. In the Tro÷dos the white flowered C. salviifolius grows mixed with the pink flowered C. creticus, but Dicladispa was found exclusively on C. salviifolius. Buhr visited Hvar from the end of March - end of April, Hering from the end of April - mid of May. Thus there are no indications excluding the possibility of a second or third generation later in the summer or autumn.

 

The young mine is an elongate brownish upper side or full depth blotch over the main vein. The larva is said to make several mines. Each time a mine is left his happened through a very rough exit, always at the upper side, and almost always at the distal end. Possibly the larva uses the peculiar spiny comb at its rear end to force an opening.

 

 

 

Later mines (or later stages of the same mine) have shallower upperside lobes that extend laterally and may occupy the whole leaf. As is evident in the transparency opposite, all frass is concentrated in an elliptic zone over the main vein. The frass, that looks rather like tar when the mine is opened, forms a layer over the bottom of the mine; the 'ceiling' is completely free of frass.

 

 

 

 

Pupation occurs in the mine. Upon our return home we found that one dead pupa was laying outside of the mine in the apex of a leaf, with behind it the characteristically untidy exit slit. I suppose therefore that the pupa leaves the mine just prior to its ecdysis

This was confrmed by an imago and an empty exuvium (also outside of the mine) found among the collected leaves. The imago enabled me, with the kind help Ben Brugge, collection manager of the Zo÷logical Museum, Amsterdam, to ascertain the identitiy of the miner.

 

Below are the main references I can give. Probably there are more, unknown to me:

Buhr H, 1930. Einige Blattminen und Gallen von der Insel Lesina (Hvar) in Dalmatien. - Sitzungsberichte und Abhandlungen der naturforscheden Gesellschaft zu Rostock [3] 2: 125-148.

Hering EM, 1967. Blattminen der Insel Hvar (Col., Dipt., Hym., Lep.). - Deutsche entomologische Zeitschrift [2] 14: 1-80.

Willem N Ellis. May 2004

 

 

 

Images:ę Willem Ellis, Holland, 2004

 

Newsletter of leafmines.co.uk 

June 2004