Bulletin 18 - November 1982: Hymenoptera Highlights I

Hymenoptera Highlights I

Since the departure of our previous Chairman and Recorder, Giles Roche, the collection and identification of Hymenoptera, with particular emphasis on the Aculeata (bees and wasps), has been continuing albeit on a more limited scale.

Several outings to the remote areas of the Emirates over the last nine months have provided approximately 75 species, some of which are new to the group's collection.

The more lucrative collecting areas around Hatta have been revisited and the grounds of the Hatta Fort Hotel are now considered to be an important contribution to the entomological environment. The more traditional collecting areas of the Wadi Faid, Wadi Jeema and Hatta Power Station still provide new species for the patient collector.

Nearer to Abu Dhabi, the Calotropis bushes between Shwaib and the Dubai-Hatta Road have continued to be successful and also have the added advantage of being within comfortable driving distance of Abu Dhabi on surfaced roads.

With the sad demise of the sewage farm, collecting in Abu Dhabi now has to be carried out in the parks and areas of roadside vegetation. However, for the self-conscious collector, the avid interest of the local populace can be extremely disconcerting and facilitate the escape of the more illusive species.

The islands around Abu Dhabi have yet to yield any substantial number of specimens. One exception to this generalisation is Futaisi, a privately owned island west of the Intercontinental Hotel. Although during the summer months the collecting is best described as limited, during the winter months several species have been netted in conjunction with the flowering of the indigenous vegetation.

Wahlah and the Wadi Murnay, both nestling in the mountains between Khor Kalba and Hatta, have been the most notable of the more remote locations visited of late. Khor Kalba is also an area which promises to be rewarding and it is intended to cover this area in greater detail during the winter months.

By far the largest superfamily recorded are the Sphecoidea (fossorial or "digging wasps"). These insects generally are solitary in nature and as their nests are made in sandy locations or hollows in trees etc, are common in plantations and wadis.

Less numerous are the species of Vespoidea, the true wasps. Nests of the social Vespa orientalis (the large brown and yellow hornet) and polistes walt (Vespidae) have been observed, complete with occupants, in various areas including Hatta and Dibba. Both species are extremely common throughout the UAE especially in wadis where surface water is present. Members of the Eumenidae family have also been collected and it appears that semi-social and solitary behaviour is displayed by members of this group.

Bees (Apoidea) are being collected in reasonably large numbers and one of the major families represented to date is the Anthophoridae with the Apidae family showing the widest distribution. One of the Apidae, Apis florea appears to be the most prevalent and can be found allover the Emirates collecting pollen from a wide 'variety of trees and flowers. The most noticeable member of the Anthophoridae is the Xylocopa or carpenter bee. These individuals are large, rotund and either completely black, black and yellow or all yellow. They are common around Abu Dhabi and can be easily confused with large beetles in flight.

Species of Megachilidae, the leaf cutting bees, have been taken at various locations in the UAE and one individual is presently assessing the advantages of the writer's dhow as a desirable family residence.

Of the other families of wasps the Pompiloidea are numerous throughout the Emirates. These are the spider hunting wasps and are mainly found in stony locations, especially wadis, or around palm trees or in fact anywhere spiders are found. Only the female hunts spiders which she paralyses with her sting and then places in the nest for the larva to feed on. It appears that the males take no interest in spiders and are generally found visiting flowers and trees.

Unfortunately both the sexes of Pompiloidea are extremely difficult to collect due to their erratic behaviour and nimble hunting tactics among the stones and bushes. Although many individuals have been sighted only a very small number have actually been caught.

Other additions to the group's collection include species of the Chrysidoidea and Scolioidea families. Both are parasites of various bees, wasps and other insects. The Chrysidoidea are bright metallic blue or green in colour and are extremely fast fliers of medium to small size. The Scolioidea tend to be large, hairy insects although as usual there are exceptions to this and smaller species have been found.

Parasites of other denominations have also been collected, e.g. Ichneumonoidea, but no work has been attempted on the determination of these specimens. A volunteer specialising in the collection and identification of the parasitica would be most welcome as would any eccentric wishing to catalogue the group's growing collection of flies (Diptera).

The identification of the hymenoptera order is a difficult task. Unlike lepidoptera, there are no works of reference that can give an exact identification of a given individual merely by comparison with a photograph. At present the group's recorders are attempting to place the specimens collected into genera and families and it is hoped that specific identification will be made by higher authorities or specialists at regular intervals.

It is also hoped that our efforts will lead to a greater understanding of the ecology of the region and the various lifestyles of the insects concerned. The writer would be pleased to receive any specimens or information that may be useful in this research.