The Principal Area of Study.
My studies mostly take place in Axarquía, the eastern part of Málaga province, along with the neighbouring parts of Granada but other parts of Andalucía are also visited each year. Except for the Acantilados de Maro-Cerro Gordo at the eastern end the coastal belt of Málaga is largely urbanised. Away from the larger river valleys, much of the land rises sharply into gully-cut hills up to 800m above sea level [asl] and up into a number of mountain ranges, notably the Montes de Málaga, Sierra de Alhama, and the adjoined Sierra de Tejeda and Sierra de Almijara. The highest point is the Maroma peak in the Sierra de Tejeda at 2060m asl.
The hills are largely cultivated where they are not too steep, though there are some abandoned areas that have reverted to scrub or rough weedy grassland. On some of the deeper soils cereals are grown but most are covered by orchards: olive and almond above 400m asl and now mostly avocado and mango at the lower levels, though a mixture of other trees, including citrus can also be seen. In some areas raisin vines are also grown. In the river valley flood plains, along with avocado and citrus, vegetables are cultivated [cf picture on 'Contact' page].
The lower parts of the mountains and hills that are not cultivated are heavily grazed by sheep and/or goats. In places oak woodland still exists [Quercus rotundifolia or Q suber with pockets of Q canariensis] and other area are pine-covered, mostly by [originally planted] Pinus halepensis; some with a mixture of oak. The pine woodlands in particular often have a broken canopy which permits a layer of scrub and herbs to grow beneath. Above the woodland sub-alpine communities can be found, though the highest parts are frequently covered in a largely bare karst landscape. The scrub habitats can be dominated by Quercus coccifera, Cistus, Ulex, Rosmarinus, Genista, Retama and other leguminous shrubs. The heavily grazed swards typically contain Phlomus purpurea and Asphodel ssp. In the damper gullies Spartium juncem and Rubus ulmifolia are common. The swards and abandoned cultivations are winter-green, drying up in May; the latter frequently dominated by tall spiny, often thistle-like species.
There is likely to be a decline in the distribution of mantids in this area at the present time as abandoned areas of cultivation are being brought back into arboreal cultivation again. The current trend is to plant avocados and mangos on land below about 400m asl and olives on higher ground. Terraces are being cut into the steep slopes using heavy machinery and the slopes below these plantations are sprayed-bare by herbicides as is much of ground below the more traditional plantations of almond, olives and raisin grapes. This leads to much soil erosion on the steeper slopes.
Over the past three years I have experimented with and refined both my rearing and studying of mantids. For sexual studies I usually catch large female nymphs a week or two before they become adult and then raise them until they are sexually mature. At this stage they will attract males. I use a small net for catching mantids which I find more useful than a standard sweep net in the woody and thorny vegetation prevalent in this area. The net in made for a kitchen sieve with the mesh removed. This is then replaced with a fine tough nylon net with the rim reinforced with soft leather. Ootheca laid under stones are relatively easy to find and can be a good source of material though those laid on vegetation can be very difficult to spot. Usually, after removing them from the stone with a sharp knife, I mount them on a short, narrow strip of wood or on a fennel stem crushed to provide a flat surface. A paper paste stick is used to fix the ootheca to the wood. I then put them in jars with plastic screw-on lid that have had a hole cut in them with a hot knife and a fine mesh glued over the hole. They are kept under-cover, outside, at the side of the house.
The first big problem encountered with the Amelinae is feeding the newly-hatched nymphs. The larger [3rd or 4th instar onwards] nymphs and the young nymphs of the larger species like Sphodromantis will happily feed on fruit flies and aphids but the young Amelinae are too small to catch flies. They eat small aphids and I have found that sufficient tiny invertebrates can be sieved, along with bits of leaf litter, from the leaf litter below some large oak and carob trees in the garden to feed the small Amelinae. They will also eat the mites and Psocoptera found in powered and rolled grains from the market. There appears to be very little carnivorous behaviour during the first two or three instars and so these tiny nymphs can be kept together. I use plastic jars which can be bought very cheaply. I put a layer of plaster of Paris in the base to keep them stable and the metal lid has two holes in it, one mesh-covered and a 2cm one with a sherry cork in it with is used for putting in food etc. Flies can be easily put into the jar from 2cm diameter glass tubes through these holes and labels are put onto the cork which enables the label to be easily transferred to another cage with the insect. When the insects are small they are kept in jam-sized plastic jars. As they get larger so larger containers are used.
They adults are often kept in plastic transparent storage containers [20cms x 12cms x 25cms] that have the central plastic section exchanged for mesh and a 2cm hole again put in the top. The aim of the cage sizes is to provide sufficient space of the mantid to move around but small enough for it to easily catch food. When they are studied they are transferred to purpose-built larger cages. Adults of the larger species are also kept in these large cages. The larger nymphs and adult Ameles are usually fed on flies but the larger species are fed mainly on crickets bought from a local pet shop. These basic foods are supplemented with other suitable insects from around the garden. For instance, Sphodromantis will feed happily on wasps, though I tend to avoid spiders as I am not sure what species they can handle and uneaten ones build webs which the mantids can get tangled in. The flies and wasps are usually caught from my compost heap as are fruit flies to start off a culture in early February when they are plentiful. They largely disappear as the weather heats up and the cultures which I rear on potato powder have to be kept in a cool box here in the summer months. The mantids were kept in cages outdoors under dappled shade on tables or shelves 60-70cms above the ground. Exposure to too much sun or excessive heat will easily kill them in plastic cages but some of the larger species appreciate some exposure to early-morning sun. Wind could also penetrate the larger cages. Although the species in this area require little humidity, the tops of the cages of the smaller individuals are sprayed in the early morning most days. They are particularly vulnerable to drying out during moulting.
Soon after moving to Spain I started looking at the Orthoptera. The ecology here is very different from that I was used to in England and so there has been a huge learning curve here. As there are no published works on the Iberian Orthoptera I spent the first year collecting information and building myself a key to the species from the information I accumulated. This I gradually illustrated with my own photographs. Being a fairly useless taxonomist, my interest focused on their ecology and I began to accumulate and record information on the habitats the different species inhabited. With the huge number of plant species here, I soon came to realised that, unlike in Britain, the plant communities here are very numerous, diverse and overlapping and that the microclimate and structure is far more important to most species than the plant composition of the habitat. This being so, I started to record the distribution of species in two of the Parque National: the Montes de Málaga and the Sierras de Tejeda and Almijara.
With increasing age and the necessity of walking long distances up hills and mountains in the summer heat carrying large quantities of water in order to record Orthoptera, I looked for some additional insects to study that required less onerous work. Having half of the Iberian species of mantid living in my garden, I have increasing turned my attention into studying them in the last few years.
I bought the “Mantids of the Euro-Mediterranean Area” when it was published and set about looking at them in earnest. During a series of e-mails I exchanged with Roberto Battiston over an odd-looking Ameles I had found, he suggested I studied the mating behaviour of the Ameles here. I took up his suggestion and for the past two to three years this is what I have concentrated on, though at the same time looked into the behaviour and ecology of all the species here as well as still keeping some attention on the Orthoptera.
Watching the behaviour of purely wild individuals is very difficult, particularly the smaller species and so most of my studies are with caged or partially caged individuals. Whilst some of the mantids are raised from ootheca, particularly species from outside this area, most of my studies of mating mantids are now with females that I have caught as largish nymphs and raised to sexually mature adults. These are used to bring in males by their pheromonal signalling. Some of these males are then watched as they interact with the female, whilst others are caught and used for single sex interactions and interactions with mated females. The males of some species also come to light at night. Males will sit on the sides of closed cages of signalling females which is a good way of catching them. For the conspecific interactional work, adults are transferred from the cages they are normally kept in to larger cages where there is plenty of room for the insects to move towards and away from each other. These cages are filled with vegetation to simulate wild conditions, though sufficiently sparse to see what is going on.
During 2015 when the females were pheromonally signalling, the lid was removed from the cage to allow the males to get straight inside. A cage is being constructed for future work that can have the sides removed as well once the female has settled into the vegetation so that the male do not have to navigate the cage sides before gaining access to the female. Collation of the data collected on Ameles up to now has strongly suggested that captive males put into a cage with a captive female behave quite differently from the behaviour of wild males attracted to a chemically-signalling female in an open cage.
The cages used for observation were normally outdoors on a table 60cm high but very occasionally observations were continued indoors under artificial light when it became too dark to see outside. In 2016 red light will be used to observe the insects in the dark. They were observed from a distance of 2-3 metres and sudden movements were avoided so as not to disturb the mantids. Each significant event and its time and where necessary, its duration was recorded. Distance measurements were made as visual estimates against a ruler outside the cage. Observations often lasted several hours and needed a great deal of patience and concentration as movements tended to occur in short bursts with long periods of stasis in between.
I have noted that modern non-filament light bulbs emit a strong sound centred around the 35-50 kHz range, varying with the type and make. It is therefore likely that many species can hear these bulbs which might affect their behaviour and so should be avoided for nocturnal observations.